case study of passive houses

Passive House Case Studies

We have gathered our best case studies for you to explore:.

Nearly Zero-Energy Family House

Sustainable solution that gives a good conscience without emptying the wallet

The House at Cornell Tech

The world's largest, tallest Passive House building is helping New York City meet aggressive CO2 targets

Family House Cherasco

ROCKWOOL insulation is at the core of this ground-breaking Passive House renovation

University Hospital Olomouc

An innovative clinic built to nearly zero-energy levels

More on Passive Buildings

Passive House

Passive house designs enable us to build houses that save energy, improve air quality and reduce noise pollution.

What is a Passive House?

Definition, principles & requirements

Welcome to the zero-energy house

Built with the right techniques, a home can produce as much energy as it uses.

ROCKWOOL Group

On the Podcast: Interviews with Buildings of Excellence Round 4 Award Winners. Listen

A CLT and Passive House Case Study

Cross-laminated timber (CLT) is taking center stage in a new Boston development set to break ground later this year. Placetailor’s 201 Hampden is a zero-carbon, full CLT, Passive House building that will be bringing 14 units of affordable and market-rate housing to Boston’s Dudley Square, with construction set to begin later in 2022. Placetailor’s development, architecture, and construction management divisions worked with Massachusetts Institute of Technology start-up Generate Technologies to provide the region with this exemplary mixed-income, mixed-use building.

There are immense benefits to utilizing CLT, despite it being still in its infancy as a building material and its unfamiliarity to many building code officials. These benefits can be captured best through the lens of the triple bottom line concept, which explores a business’s or a product’s impacts on the planet, people, and profitability. Placetailor fused the triple bottom line concept and its dedication to Passive House design to forge its “Future Housing” practice.

The CLT utilized at 201 Hampden is processed using timber that is sustainably harvested in the United States. The raw material is manufactured into cross-laminated panels or strips of timber that are compressed together. For this particular project, the team is utilizing reclaimed eastern hemlock that was the recent victim of a blight; fire and structural testing are currently being done on the CLT panels made from this stock.

The nature of the material itself acts as a long-term carbon storage vessel. By utilizing CLT as the structural components of a building, the need for concrete and steel are eliminated, or greatly reduced. This material choice substantially lowered the carbon footprint at 201 Hampden, essentially turning the building into a carbon sink.

Additionally, CLT provides surprisingly beneficial thermal properties for exterior assemblies, aside from being a structural component.  While the strict R-value is very low for timber, and is only R-6 per CLT panel in the typical wall assembly of this project, the thermal mass of mass timber reduces the amount of potential thermal bridging moments and helps normalize the interior temperatures. Consider a log cabin, which might only have an overall wall R-value of 6 but has helped many survive in cold climates. Thanks to the CLT and continuous exterior insulation layers, 201 Hampden will act like a next-generation log cabin. As an extra bonus, CLT’s thermal mass allows for minimizing the thickness of the exterior insulation, translating into less embodied carbon—while still adding up to a lower operational carbon footprint throughout the life of the building.

Biophilic design attests that humans have an innate desire to connect with nature or elements that remind us of natural settings. CLT, having a wood-grain texture and finish, will impact individuals by providing a visual and haptic sensation of being surrounded by woody plant species. Beyond having a soothing physical appearance, the material is healthy for the indoor environment. CLT is a safe material to interact with because it does not emit unsafe levels of volatile organic compounds (VOCs)—a critical requirement for achieving safe indoor air conditions and Phius certification. At 201 Hampden, the design team opted to expose the CLT structure to the indoor environment as much as possible. This choice reduced the need for additional materials and paint, which ultimately cuts back on the number of emitted VOCs.

Marginalized communities are often impacted more severely by the multiple crises of today, whether it’s the climate crisis, the health crisis, the housing crisis, or the displacement crisis caused by inequitable development. By utilizing a material such as CLT in a mixed-income project in the heart of Roxbury, we move closer to equitable growth in the neighborhood, creating a development where people of all socio-economic levels are able to benefit from CLT’s psychological and physiological benefits and participate in the proactive reduction in their carbon footprint.

CLT has proven itself as a beneficial building material for its constructability and ease of assembly. As mentioned previously, CLT can replace the need for other structural materials, when planned for properly. This reduces the need for more trades to be involved in a project, simplifying construction site coordination. The pre-fabricated panelized construction process expedites the project and cuts back on the overall timeline.

While this first foray into CLT has come with the cost of a learning curve for Placetailor, the lessons learned can be applied to taller buildings, where the CLT can replace typical steel construction with a considerably greater cost-effectiveness. During the course of design, the team has also been introduced to start-ups who are working to incentivize the selection of mass timber through brokering carbon credits. Economics drive so much, and so this financial connective tissue will no doubt prove invaluable for turning the construction industry toward carbon-neutral materials.

Future Housing

At Placetailor, we have been designing and building exclusively to Passive House, net zero-energy, or net zero-carbon standards for over a decade. We have found that the majority of people looking for a home are less concerned with a particular sustainability certification and instead are more concerned with whether their homes can facilitate their zero-carbon lifestyles. They want to know that it was developed with support from the community, by companies within the community, and by designers and builders from the community who are able to continue to live in the community. They want to know that it is healthy and comfortable. All of this, when achieved consistently at or below market rate, we refer to as Future Housing.

Phius has been a guiding star in our continual and evolving definition of Future Housing. The handful of critical principles and targets provide a clear path to not just lower energy use, but also to the ancillary benefits of health, comfort, and sound attenuation that round out the core of our Future Housing standard. (For those who are unfamiliar with Phius requirements, to achieve certification a project must comply with the U.S. EPA’s Energy Star and Indoor AirPLUS program requirements, as well as those of the U.S. DOE’s Zero Energy Ready Home program and the typical Passive House metrics.) So, while not every project of ours has been certified, every project has been within reach, and every project since our inception in 2008 has exceeded the AIA 2030 Challenge energy reduction targets.

Design Process

Our Future Housing starts at the project's conception, making sure clients and investors are aware of and on board with our mission to achieve Passive House standards. With open communication and understanding established, the design process begins. When 201 Hampden started the schematic design phase, our certified Passive House consultant (CPHC) reviewed Phius’s requirements with the project architect to ensure these would be incorporated early in the design process. Thorough energy modeling and analysis allow the design team to make informed decisions.

What follows is a procedural breakdown of Placetailor Elton Hampton Design’s (PTEH’s) integrated design process starting with preliminary analysis and ending with simulated energy modeling. For orientation, the project is located in Boston, Massachusetts, which is situated in climate zone 5. This is a heating-dominated climate with low outdoor humidity levels in the winter.

Preliminary Analysis

Steps 1 and 2, undertaken during the early analysis phase, can be performed without the need for energy modeling software, making it accessible to all. Steps 3 and 4 require light energy analysis software that is intuitive for an end-user to learn and implement.

Step 1 . Analysis begins with volumetric and surface area calculations, specifically surface-to-volume ratios (SVR) and heat loss form factor (HLFF) calculations. SVR is a measure of massing volume efficiency of a building's design (see Figure 1). The calculation is performed by taking the sum of the entire building envelope and dividing it by the building's gross volume (envelope area / gross volume). The ideal target ratio range is from 0.24 to 0.3.

HLFF measures the compactness of a building. The more compact a building is, the less insulation is needed to achieve the building's energy reduction targets. Inversely, the less compact a building is, or the higher the HLFF, means that it is less efficient, and more insulation will be required. The calculation is performed by taking the interior conditioned floor area and dividing it by the sum of the building’s entire envelope area (iCFA / envelope area). The ideal target is equal to or less than a ratio of 2.5.

When these calculations were crunched for Hampden, the design failed to be within an acceptable range for SVR, but performed very well for the HLFF ratio.

These results signaled to the design team that Hampden has a good ratio of interior floor area to exterior envelope area, but that the shape of the building's volume is not efficient. Hampden is shaped like a triangle, which is one of the least efficient volumetric shapes. This means that the building will require more energy to heat and cool the space. Alternatively, additional upfront money can be spent on more robust assemblies and systems to compensate for this.

Step 2 . Calculating a building's window-to-wall ratio is another accessible means of designing an efficient building. As a rule of thumb, it is ideal to target 18-20% of glazing to wall area across an entire building (see Figure 2). The amount of glazing recommended per façade orientation is dependent on the location, in addition to project type. If the project is located in a heating-dominant climate, it would be beneficial to install more windows on the south façade and fewer on the north. This will help to best utilize solar heat gain on the south façade and mitigate against heat loss on the north-facing façade. To hit the building’s energy reduction targets, the design team may need to specify different glazing solar heat gain coefficients (SHGCs) for individual facade orientations.

Step 3 . This part of the energy analysis utilizes an Autodesk Revit plug-in called COVE.tool. Figure 3 is a solar exposure diagram showing the averaged amount of sun that a surface receives throughout the year. The green façade, which is east-facing, is receiving morning sunlight, yielding a 50% solar exposure rate. The southwest façade, which is mostly yellow in color, is experiencing mid-afternoon sun and is receiving 80% solar exposure. This analysis informed the design team that windows with a lower SHGC, such as 0.25, should be specified for the southwest façade to reduce the amount of solar heat gain.

Figure 4 is a Spatial Daylight Autonomy diagram. It is showing visible light transmittance within the residential units. The floor area closest to the windows are receiving an uncomfortable amount of light, indicated by the red and orange tiles. This is suggesting the design team could reduce the overall glazing percentage and still maintain a comfortable amount of interior daylight. When indoor environments receive excessive light, fabrics can become sun bleached and surface glares can affect occupant comfort.

Step 4 . This step consists of analyzing photovoltaic (PV) production on site. This is computed via an online software tool called Helioscope (see Figure 5). Oftentimes, with medium to large size multifamily projects, it won’t be possible to cover the entire building's energy usage with on-site solar. Such is the case for Hampden. In these cases, it’s good to target a PV output large enough to cover a building’s miscellaneous electrical loads.

Simulated Energy Modeling

Step 5 . This phase of robust energy modeling starts in schematic design and continues into construction documentation. Energy modeling will sometimes extend into the construction administration phase, if there are change orders or value engineering efforts later in the project. PTEH utilizes WUFI Passive software for advanced analysis of hydrothermal conditions while also taking shading, daylight, and climate into account.

Before schematic design ends, the CPHC will conduct a feasibility study that models out three different case studies using WUFI. This allows a cross comparison of different assembly and mechanical, electrical, and plumbing (MEP) system options. The CPHC presents these options to the client and design team in a collaborative setting to weigh the pros and cons of each option.

Case 1 . Code Minimum Design . The first energy model is built to the project’s local energy code minimum requirements. This provides the design team and client with a baseline understanding of how their building would perform if no Passive House concepts were taken into consideration.

Case 2 . Architectural Drawing Set . The second WUFI case study will be modeled based on the architect’s narrative for assemblies and systems. Usually, the architect’s narrative meets or exceeds the minimum energy code requirements.

Case 3 . Passive House . The last energy model is designed to Passive House certification. This takes the architect's design narrative and enhances it to hit the energy reduction targets.

The target energy reduction criteria specific for 201 Hampden are listed here. These numbers are determined by Phius and are customized for 201 Hampden’s design and location.

Hampden’s Passive House Target Design Criteria:

HEATING DEMAND:            4.6 kBtu/sf/yr

COOLING DEMAND:            5.4 kBtu/sf/yr

PEAK HEATING LOAD:            3.8 Btu/hr/sf

PEAK COOLING LOAD:            2.7 Btu/hr/sf

SOURCE ENERGY CONSUMPTION:    4,683 kWh/person /yr

Below is how Hampden performed under each of the three different case study scenarios. Green text indicates numbers that meet or exceed the Phius requirements, while red text indicates points of failure.

CASE 1 - Code Minimum Design

HEATING DEMAND:            6.75  kBtu/ft2yr

COOLING DEMAND:            2.64  kBtu/ft2yr

PEAK HEATING LOAD:            7.8  Btu/hr ft2

PEAK COOLING LOAD:            2.93  Btu/hr ft2

SOURCE ENERGY CONSUMPTION:    5,583  kWh/person /yr

CASE 2 - Architectural Drawing Set

HEATING DEMAND:            2.43  kBtu/ft2yr

COOLING DEMAND:            4.36  kBtu/ft2yr

PEAK HEATING LOAD:            3.89  Btu/hr ft2

PEAK COOLING LOAD:            3.12  Btu/hr ft2

SOURCE ENERGY CONSUMPTION:    3,667  kWh/person/yr (with PV installation)

CASE 3 - Passive House

HEATING DEMAND:            1.46  kBtu/ft2yr

COOLING DEMAND:            3.63  kBtu/ft2yr

PEAK HEATING LOAD:            3.24  Btu/hr ft2

PEAK COOLING LOAD:            2.59  Btu/hr ft

SOURCE ENERGY CONSUMPTION:    3,566  kWh/person yr (with PV installation)

201 Hampden performed well in the Case 2 scenario due to the architect and design team utilizing robust assembly and system assumptions. Therefore, very little had to change to satisfy Passive House criteria in Case 3. Updates to the architectural drawing set model to achieve Passive House included a reduction in the number of windows, a higher performing HVAC system, and minor changes in assembly R-values.

In many instances, energy modeling can be used as a cost savings tool by helping teams dial in on the exact amount of insulation and performance needed to hit their Passive house targets. For 201 Hampden, the project was able to reduce the overall amount of insulation and windows that the design team had originally specified, providing some cost savings.

Step 6 & beyond . With the feasibility study completed, the CPHC continues to collaborate with the architect and design team to best detail assemblies and building systems that maintain the Passive House criteria targets. Below are the current assumptions for 201 Hampden’s building envelope assemblies. Components are listed in order from outside to inside (see Figure 6).

Slab on grade :

-Crushed stone

-4 inches of compression strength EPS rigid foam board

-Under slab vapor barrier (this also serves as the air barrier)

-4-inch concrete slab on grade, polished and sealed for final finish.

Foundation Wall :

-Drainage board

-below grade rated insulated sheathing w/ 3 inches of rigid insulation, taped at all seams (this serves as the air barrier)

-fluid applied waterproofing

-concrete foundation wall

-1 inch of interior EPS rigid insulation board between furring strips

-two layers of gypsum for fire rating.

Exterior Wall, Type 1 :

-siding per elevation

-siding attachment system

-Insulated ZIP system w/ 3 inches of rigid insulation, taped at all seams (this serves as the air barrier)

-6 7/8-inch CLT panel

-2x3 interior service cavity w/ mineral wool insulation

-two layers of gypsum sheathing for fire rating.

Exterior Wall, Type 2 :

-2x6 wood stud filled w/ mineral wool insulation

-1 3/8-inch air gap filled w/ mineral wool insulation

-2x3 service cavity w/ mineral wool insulation

Roof Assembly :

-TPO roofing membrane, welded at all seams.

-Underlayment board

-Tapered EPS insulation w/ 6.5 inches of buildup at the lowest point

-Continuous air barrier, taped at all seams

Mechanical, Electrical, and Plumbing Systems

All systems are fully electric, as no gas will be utilized in this project.

Mechanical Ventilation System . Ventilation systems are required to be balanced, or within a 10% pressure difference as specified by Phius. The WUFI Passive energy modeling analysis informed the design team that a semi-centralized energy recovery ventilation (ERV) system would perform efficiently. In climate zone 5, ERVs are preferable to heat recovery ventilation (HRV) systems. This is due to an ERV’s ability to recirculate humidity back into the building instead of exhausting it all to the outdoors like an HRV would do. This capability is critical for maintaining occupant comfort in the heating months when the relative humidity is very low. When indoor air becomes too dry, occupants may begin to experience irritation to their nose, throat, and eyes.

In Figure 7, the yellow highlighted square is the ERV closet with ducted supply and exhaust runs shown to each unit and room. The ERVs are located along an exterior wall to reduce the intake and exhaust ducting to the outside. The shorter these runs can be, the more efficient the system will operate. Semi-centralized in this case means the project is installing one ERV per floor. This reduces vertical changes and the need for fire dampers within the building. It also allows for more efficient distribution and runs. The resulting cost savings can be spent on a higher performing ERV. We are specifying a Topvex TR800 with MERV 13 filters for the supply air and MERV 9 for the exhaust air. Topvex TR800 is AHRI and CAS certified.

Mechanical Heating and Cooling System . A thermostat is required in each residential unit to control the heating and cooling systems, allowing for greater occupancy comfort and reducing wasteful heating and cooling. At Hampden we are specifying a decentralized system, with one Ephoca heat pump per residential unit (see Figure 8). The heat pumps will be placed in the common area of the units, such as in the living room. In order to provide heated and cooled air to the bedrooms, all bedroom doors will be undercut by ¾ inches to allow air flow. In addition to undercutting doors, jump ducts will be installed leading to each bedroom. The jump duct fans will be tied to the bedroom thermostats and kick on when room temperatures are above or below the thermostat setpoint. This method reduces the need for additional heat pumps per bedroom.

Plumbing System . The team opted for a centralized domestic hot water system with heat pump heating and storage tanks. Due to the restricting floor plan layouts, there is not enough room in each individual unit to accommodate a decentralized system. The design team specified the SanCo2 heat pump water heater. There will be four 119-gallon storage tanks on the ground floor in a conditioned storage room, as indicated by the yellow circles in Figure 9. The yellow highlighted rectangles are the exterior heat pump condensers. This system utilizes a CO2 refrigerant line, which reduces system heat loss and has a low global warming potential. This system is Energy Star rated and has a heating coefficient of performance (COP) of 2.8 - 5.5, depending on the outdoor temperature.

Looking Ahead 

The integrated team committed to the use of CLT in order to learn and demonstrate—just as we have in previous explorations of materials, means, and methods used in prior Future Housing projects. While there was a cost to the learning curve, there are clear benefits to its application on other current and future projects. Particularly for high-rise housing, CLT is now a go-to material for the team, because the economics make it cost competitive with a steel structure. The typically smaller spans for residential spaces also provide opportunities to reduce the floor-to-floor heights without sacrificing ceiling height.

The project has yet to be built, and there will no doubt be more lessons to learn before its completion. For the sake of our mission—to facilitate the rapid transformation of all housing to zero-carbon Future Housing—the team looks forward to sharing each and every one for the benefit of all the other teams out there.

—Liz Hauver is a CPHC and the energy design manager at PTEH. 

Project Team:

Developer: Evan Smith, Director of Placetailor Real Estate Development

Architecture: Placetailor Elton Hampton Design

Principal-in-charge: Bruce Hampton AIA

Project Manager: Juliet Borja AIA

CPHC / Energy Designer: Elizabeth Hauver

Project Designers: Mike Marotta RA, Sam Naylor RA

Design Consultant: Generate Technologies

Structural Engineer: Studio NYL

MEP Engineer: Zade Engineering

Civil Engineer: Merrill Engineering

Construction Manager: Felipe Francisco RA, PT Build

Passive House 101

• Passive House Intro
• Why: Passive House Benefits
• What: Passive House Standards
• How: Passive House Design Principles
• Passive House Retrofits
• Passive House LIVE!
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• Terms & Conditions

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Case Study: Madison Passive House by Mowery Marsh Architects

Can a house with modern European sensibilities slip into a suburban New Jersey neighborhood without offending the neighbors? What’s more, can it achieve Passive house certification without looking a little forced? This unassuming but self-assured house by Mowery Marsh Architects does both, even though it was built by a general contractor who knew next to nothing about Passive house standards. It is an example of how creativity in its purest form is also about collaborating, making connections that lead to dynamic buildings and streetscapes.  

The owners, who are from Belgium, lived just down the block when they bought this lot containing a one-story teardown. Although the existing house was dilapidated, the lot was deep and had beautiful mature trees. The couple envisioned a light-filled, four-bedroom house with tall ceilings, minimal detailing, and flowing spaces. This seemingly easy request, however, challenged the architects from the start.  

“They had a great design sense and the palette they were interested in excited us, but we’re on this street of houses with 8-foot ceilings and dinky porches,” says Jennifer Mowery, AIA, who designed the house with her husband and business partner Brian Marsh, AIA. “They wanted 10-foot ceilings. How would we give them what they wanted and make this house not feel like a monster on the street?”  

Warm Modern

The two partners were able to realize their clients’ aesthetic goals and preserve the street scale, in part, by drawing an L-shaped floor plan that projects into the backyard. The front reads as an updated bungalow with its front porch, a long dormer like the neighbor’s, and a second story tucked under the roof. A columned porch hung with four timeless “barn lights” reinforces the familiar rhythm of the house’s two-over-two punched windows.  

It’s clear something else is going on, though, and the crisp, black-and-white exterior is a clue. Visitors step up onto the long, metal-roofed front porch and into a two-story entryway with a stairway to the right and a mudroom and powder room to the left. From there they step down into the great room containing a living and dining area with large expanses of glass, and the kitchen beyond. The slightly raised front porch and foyer was a way to give the clients their 10-foot ceilings without creating too much massing outside. “The mudroom and front stairs are compressed, but not much, because that area is open to above,” Jennifer says. “It meant taking pieces of the puzzle that everyone has and rethinking them, making them more pure and clean.”  

Inside, building a modern dwelling in an older neighborhood also suggested a more nuanced approach to the double-height living space. The architects finessed this by designing a one-story window wall at the back of the house but inserting a bridge at the second floor with the two kids’ rooms on one side and a guest room and master suite on the other; this allowed for a two-story window slot at the back that creates the airiness the owners were after and floods the first floor with light. “I personally like living spaces that have some intimacy,” Jennifer says. “The house has a two-story space, but it’s not the space you’re hanging out in. It’s nice to treat circulation with a kind of grandeur.”

Other moves also nudge it toward hominess rather than grandeur. Extending the kitchen into the landscape allows the owners to experience the house exterior while they’re inside and to see into the kitchen from the living room. That connectedness “creates a story,” Jennifer says. The footprint also gave the architects more skin on which to place windows. “The kitchen and the master suite above it aren’t huge spaces but feel quite generous because they get light from three sides,” Jennifer says. The L shape makes the master bedroom feel like a sanctuary, tucked into the trees at the end of the finger, with a balcony overlooking the yard.  

The owners splurged on wide oak plank flooring with a matte finish, which gives the house a Nordic feel and marries well with the natural palette of black metal windows, walnut cabinets, and creamy white walls painted Benjamin Moore China White. Most modern designers would go for a purer white, and the wife hesitated, but she was pleasantly surprised at how well it worked, Brian says. “The colors we presented were very warm, not stark white, and she said she would never have picked the white, but she loved how it gave the house warmth throughout and avoided a cold modern box with black windows,” he says.

“Back in the day when people used creamy whites, they were pairing them with tan and beige, and everything felt muddy,” Jennifer adds. “This lends a little softness, so that when you do striking navy blue in the bath, it still seems homey and inviting. It’s something we play with in all our projects.”

Passive Aggressive

This is Mowery Marsh’s first certified Passive house, though a previous renovation fell just short of the requirements. Because most of their clients don’t have Passive house goals, Mowery and Marsh try not to lead with the conversation, but it’s a layer of rigor they apply to every commission. “Once you do Passive house construction, you can’t go back because the detailing of a regular house is so bad,” says Brian, who is trained in Passive house standards. These owners were familiar with the concept, however, and saw the value of getting the house certified. “They thought, absolutely, why wouldn’t you build this way?” he says.  

It took some serious networking to find a Passive house–trained subcontractor who could oversee critical tasks such as insulation and air sealing. The general contractor, Mike Passafiume, embraced the building science aspects and said, “You tell me what you want me to do, and I’ll do it,’” Brian recalls. “But I knew from past experience that wasn’t going to work.” Brian found Jason Endres through a supplier of Passive house materials. Jason is certified through PHI, a European standard, and this would be his first Passive house project, too.

If the building lives on the suburban edge aesthetically, it is buttoned down at heart. Mike’s crew used conventional 2×6 framing and screwed TGIs, or wood I-beams, outboard of the 2x6s to create a thermally broken, 12-inch exterior cavity filled with dense-packed cellulose and wrapped with a vapor barrier. “We had to have blower door tests even before we insulated, to check the airtightness of the taping and barriers they put up on the outside of the house,” Mike says.  

EPS rigid foam further insulates the envelope—12 inches around the foundation and 8 inches under the basement slab, plus foam glass under the foundation footings. “Our goal was to thermally break the foundation from the ground so you have the entire concrete mass acting as a thermal battery,” says Jason. “It sounds corny, but the house operates like a beautiful symphony. You have the ERV that’s constantly exchanging air, the triple pane windows, and the insulation, all doing their part to be passive.” The exterior was finished with Boral cladding, which has a crisp edge but looks like wood.

While acknowledging that the build-out was “a lot more involved” than on a conventional home, Mike was impressed with how well the house hit its targets. “It’s a cool design and barely needs any heat—and sound-wise, too; it’s very quiet inside,” he says.

Perhaps the most rewarding outcome for Mowery Marsh was assembling the team that could make this happen. “I think it’s significant that nobody on this construction team had ever done a Passive project,” Jennifer says. “You have to find someone who really wants to do it right. They have to have the drive to really futz with the details of every penetration.” The couple also welcomed the opportunity to design a forward-thinking house in an older established neighborhood. “We wanted people to understand that even in a suburban New Jersey town, you don’t have to be shoehorned into your vernacular but can still do something that belongs,” Jennifer says.

Plans and Drawings

Project Credits

Madison Passive House

Madison, New Jersey

ARCHITECT: Jennifer Mowery, AIA, and Brian Marsh, AIA, Mowery Marsh Architects, Hoboken, N.J.

BUILDER: Mike Passafiume, Home Improvements Plus LLC, Long Valley, N.J.

PASSIVE HOUSE CONSULTANT: Jason Endres, Endres Home Builders, Nutley, N.J.

BUILDING SCIENCE: Levy Partnership, New York

SITE SIZE: 0.6 acres

PROJECT SIZE: 3,400 square feet

CONSTRUCTION COST: Withheld

PHOTOGRAPHER: Haris Kenjar

Key Products

COOKTOP: Thermador

COUNTERTOPS: Caesarstone

DISHWASHER: Miele

ENTRY DOORS: Emtek

FAUCETS: Watermark (kitchen)

GARAGE DOORS: Clopay

HVAC: Mitsubishi mini-splits

INTERIOR DOORS: Trustile

LIGHTING: One Forty Three, Rejuvenation, Cedar Moss, Atelier de Troupe

POOL DECKING: Resysta

PORCH LIGHTS: Barn Light Electric

OVENS: Miele

REFRIGERATOR: Thermador

ROOFING: Sheffield Metals

THERMAL AND MOISTURE BARRIERS: Intello

UNDERLAYMENT/SHEATHING: ZipWall

WASHER/DRYER: Bosch

WEATHERIZATION: Mento

WINDOWS AND EXTERIOR DOORS: European Architectural Supply

WINE REFRIGERATOR: Miele

Case Study: Casa Linder by Buchanan Architecture

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The Passive House

Find out how these houses were designed to be modest, sustainable, affordable and attractive to bakehouse builders and social housing providers.

The overall aim of the project was to create an exemplar of three terraced houses as a catalyst for the wider building industry, and as an inspiration for future housing design and development.

The houses use the rigorous German ‘Passivhaus’ standard for energy efficiency, resulting in ultra-low-energy houses which dispense with conventional heating systems altogether. In fact, the heating load is so small that a hairdryer could be used to heat the house.

The houses were designed to be quiet, modest, sustainable, affordable and attractive to both volume house builders and social housing providers alike.

They were erected in only nine days by site operatives who were previously unfamiliar with this type of prefabricated, modern method of construction.

Case study: The Passive House

Download this case study to take away key learning and project information from The Passive House.

Timber qualities

The Passive House units use a locally manufactured PassiveWall™ timber frame closed panel system. This ensures a high standard of construction quality and accuracy while providing extremely low U-values and high levels of airtightness. The panels are made from home-grown Scottish timber with an insulated core of recycled glass wool made from 80% recycled glass bottles.

The external panels are pre-wrapped with a thermal foil membrane and internally with a pre-fitted thermal vapour barrier. This provides the main airtight seal and an extremely high level of airtightness.

The external units are clad in locally sourced Scottish larch timber sourced within 60 miles of the site. They are broken by continuous vertical reveal boards and vertical square-edged boards with cover battens to the rear elevation. The cladding is left untreated to weather naturally to a silver-grey colour, embedding the buildings within the landscape.

Locally sourced Forest Stewardship Council timber was also specified for cladding battens, skirtings, cills, door posts and door facings.

Special timber-related features

The terrace has achieved an 80% reduction in energy by using a locally manufactured off-site prefabricated closed panel system. It also uses high-performance windows to provide a super-insulated airtight building fabric.

Ventilation heat losses are massively reduced while ensuring excellent thermal comfort internally.

A balanced mechanical ventilation system also reduces heating bills and provides a cleaner, fresher quality of indoor air. Hot water is provided from an air source heat pump.

Biodiversity is enhanced through careful landscape design and the use of local species, enhancing of wildlife habitats, composting, and providing opportunities for food production.

Image credit: Ewen Weatherspoon

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Our website includes a web-based resource that showcase s sustainable, traditional, innovative, recycled and low carbon building materials. If you are looking for inspiration or information on different types of materials to consider for your project, visit our materials library.  

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Passion project: the passive house that raised the roof on sustainable living

A family home constructed on derelict land in Melbourne sets new standards for a hard-working eco house

T he overlooked plot that Marc and Felicity Bernstein-Hussmann ended up building a house on was deemed unfit for construction use by their local council in Melbourne , Australia, and so they faced extreme hesitancy from any bank to lend for development. Despite this, they pushed on with plans, even moving into a motorhome for four years while they went through the planning and saving process for their new home. Their tenacity was rewarded when both the council and bank U-turned, and their dream became a reality.

But what started life as a wedge-shaped piece of derelict wasteland – situated next to a 10-storey apartment block, double-storey housing site and a busy train line in Coburg, Melbourne – has been transformed by the couple into a modern passive house.

The Passivhaus was originally developed in Germany in the 1980s by Dr Wolfgang Feist, a physicist, and Professor Bo Adamson, a construction expert, who were inspired by medieval dwellings built in Iceland. The concept is underpinned by five guiding principles: airtightness; thermal insulation; mechanical-ventilation heat recovery; high-performance glazing; and thermal-bridge free construction. These eliminate the need for artificial heating or cooling systems. Taken together, the guiding principles meet the rigorous requirements of the International Passive House Association .

German-born Marc and Felicity, who studied architecture before moving to Australia, have created a working prototype for a new generation of passive house – Hütt 01 Coburg – to be created under their brand Home by Hütt . Designed as both an experimental case study and a home for the couple and their three children Anna-Lena, 16, Leon, 12, and Joshua, 10, the house showcases their passion for sustainable and contemporary design and for regenerating smaller spaces of derelict urban land. The idea of the passive house has been gaining traction in Europe and the UK, but in Australia it is still relatively new, with fewer than 50 houses certified.

“Passive houses offer a new way of living with incredible environmental benefits and substantially reduced power costs,” says Felicity. A constant 19C to 21C is maintained indoors despite temperatures that drop in Victoria to below 5C. “We are passionate that innovation is combined seamlessly with luxury, wellbeing and beauty. There does not need to be a visual compromise.”

The all-electric house, accessed via a blue stone laneway, was modelled initially in 3D to consider the impact of every detail: the orientation to the sun to maximise solar-heating gain; cross-ventilation to flush out heat in the summer; the introduction of cooling through-breezes from the moist, shaded rainwater garden that connects to the main living area, and staircase skylights to act as a chimney against overheating.

The house is built on a concrete slab that’s continuously insulated to prevent heat transfer (thermal bridging) where the slab meets the walls. Wood-fibre insulation stores carbon, mitigates thermal bridging and is breathable – unlike conventional polystyrene insulation that can collect mould and condensation. The walls and roof are built with prefabricated cross-laminated timber (CLT) and take a week to erect, with noise-reducing, carbon-storing and insulating properties a given.

The small internal footprint works incredibly hard, and the steep pitched roof creates space in the children’s bedrooms, with mezzanine beds above areas for play, study and relaxation. The capacious feel is embellished by heavy-duty nets just above head height in the bedrooms and at the top of the stairs, which optimise space.

On the ground floor, thoughtful spatial planning has created distinctive zones for cooking, eating and relaxing – neutral, calm spaces that have a timeless appeal. The sunken-lounge flooring is a bespoke concrete mixed with recycled aggregate. Like terrazzo, it adds a refined touch and complements the marble and wood used in the kitchen – another bespoke design by Marc and Felicity. All storage is located on the ground floor, hidden behind black-stained American oak units and artfully worked into wardrobes, cupboards, a study nook and under-seat cavities.

The laundry room and bathrooms feature bespoke detail: curved surfaces, a brass washstand designed by Felicity and high-end sanitaryware.

Unexpected design touches delight at every turn – light-induced patterns streaming into the stairwell from west-facing open exterior brickwork that offers a low-level sneak peek into the house; a garden window handpainted by Anna-Lena, and secret doors and passageways connecting the children’s bedroom spaces.

“A connection with nature inside and out is important to us,” says Marc. “Living biophilic walls enhance the ventilated air quality, eliminating allergens and increasing a sense of wellbeing.” A quirky bridge suspended over the courtyard connects to the roof garden planted with native grasses and dichondra, and a quiet rain garden which collects water that runs off the green roof. In the main garden stepping stones lead you to a wood-fired barbecue area, a goldfish pond – which irrigates a vertical kitchen garden – and a circular wooden deck area.

This house is living proof that building a sustainable home can be compatible with an urban location and a small footprint. As climate change intensifies, quality over quantity will become an ever-important design goal. With Passivhaus technology supporting sustainable choices and enhancing a sense of comfort and luxury, one can’t help but feel that this new generation of architecturally designed homes is the only way forward for building a better future.

hutt.com.au

• The Observer

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Passive House Case Study: A Journey Towards a Sustainable Future

Dec 13, 2023 | Blog | 0 comments

The story of Daragh and Yuki Hayes takes place in London, Ontario and starts with a desire to recover and rebuild sustainably after a devastating house fire. This unfortunate event catalyzed their exploration into passive housing, guided by the expertise of Just Working Construction . Their goal was not just to build a new house but to create an energy-efficient home that could stand the test of time and set a new standard in residential construction.

Who Are Daragh and Yuki Hayes?

Daragh and Yuki Hayes, along with their elementary school-aged son, unfolded as a poignant case study in resilience and sustainable rebuilding. Their journey began with a devastating event in September 2021 – a fire that ravaged their almost century-old home during roofing repairs. The fire, which started on the part of the roof with a low-grade slope, quickly spiralled beyond control, marking the beginning of a challenging period marked by insurance complications and temporary fixes that failed to protect their home from further damage.

The Hayes family’s plight was compounded by the ineffectiveness of the initial response to the disaster. The temporary tarping and repairs proved inadequate (3 attempts!), leading to issues like moisture intrusion, rodent infestations, and most notably, mold that was deemed impossible to remove without bringing down the home. This series of events ultimately led to their home being written off by separate teams of environmental hygienists; it wasn’t officially condemned but had become untenable due to mold and other damages. The decision to demolish and rebuild, originally stemming from a plan to repair and retrofit our home, was ultimately compelled by the extensive exposure of the property to the elements, pushing us beyond mere necessity and towards a vision for a better future.

From Ashes to Innovation

The old house, lacking in modern energy-efficient features and not well-insulated, stood in stark contrast to what the Hayes aspired for their next home. Daragh, a college professor at Fanshawe, had long been concerned about climate change and was actively pursuing ways to reduce his family’s carbon footprint, driven by a desire to create a lasting legacy. His pursuit of a long-term, generational solution in energy efficiency led the family to embark on building a home utilizing passive house design principles, albeit without full certification, mainly due to the high cost of certain components like passive-certified windows.

Their collaboration with Just Working Construction was a pivotal turn in realizing their dream. Despite being outside JWC’s typical working radius, the uniqueness of their situation and the potential to create something truly sustainable and efficient brought them together. This project was not just about rebuilding a house; it was about setting a new standard in residential construction – creating a comfortable, sustainable, and resilient home that would stand as a testament to innovation and environmental stewardship.

The Vision: Sustainable and Energy Efficient

Daragh and Yuki Hayes envisioned a home that meets their family’s immediate needs and stands as a sustainable and energy-efficient legacy for future generations. Their vision went beyond mere construction; they aimed to shape a living space that embodies sustainability in every aspect from the ground up. In prioritizing low energy use , especially in heating and cooling systems, they sought to minimize environmental impact and carbon footprint. The design of their home was crafted by Danielle Gignac of Invizij Architects with a focus on family-centric needs, ensuring comfort and functionality.

This vision aligns with the growing trend of passive buildings, where energy efficiency, performance, and smart use of resources like light and heat are central. Their journey adds to the evolving narrative of passive house case studies, demonstrating how homes can be built to meet stringent energy standards while offering a warm, comfortable, and sustainable living environment. Their project, processed and developed with care, is a testament to what can be learned and achieved in sustainable residential development.

The Project Team’s Role: Crafting a Future-Proof Home

Led by Adam Vandersleen , the project team at Just Working Construction embarked on this ambitious project with a deep understanding of Hayes’ vision. Their expertise in passive house construction was instrumental in turning the concept into a tangible reality.

Role of the Project Team:

• Innovative Design : Incorporating cutting-edge passive house technologies and materials.
• Attention to Detail : Focusing on every aspect of construction to ensure optimal energy efficiency.
• Collaborative Approach : Working closely with the Hayes family to align the project with their vision.

Overcoming Challenges in Building a Passive House

Faced with the aftermath of a house fire and navigating insurance complexities, the Hayes family, with Just Working Construction, turned obstacles into opportunities. The project in a challenging urban setting demanded a unique approach to building a passive house. Leaning on two elements helped with breaking down barriers surrounding passive homes in this setting.

• Resilient Strategies : Employing innovative solutions to overcome site and design challenges.
• Adaptive Building Science : Utilizing advanced building science ensures the project meets passive house standards despite constraints.

The Core of Passive House Design

This project exemplifies the essence of passive house building, combining elements like airtight construction, superior insulation, and high-performance windows and doors. These features are essential in achieving low energy consumption, crucial in the city’s cold climate.

Highlights:

• Energy Efficiency : Reduction in energy use through efficient design and materials.
• Comfort and Health : Focusing on indoor air quality and consistent indoor temperatures for year-round comfort.
• Affordable Technologies : Incorporating cost-effective and sustainable building technologies.

A Truly Sustainable Home for the Hayes Family

As the project nears completion, it stands as a model of sustainable development. This single-family home is a case study of turning adversity into an opportunity for learning and growth, setting a new standard in passive house construction.

Future Outlook:

• Legacy and Longevity : Building a home that fits the Hayes family’s needs now and for decades to come.
• Environmental Impact : Contributing positively to the climate and setting a precedent for future developments.
• Educational Opportunity : Serving as a learning example for clients, builders, and the community on the benefits of passive house design.

Harnessing the Power of Passive House Technology

The Hayes’ passive house project in the city represents a paradigm shift in residential building, embracing zero-energy and low-energy building concepts. This case study of a single-family home underscores the transformative power of passive house technology in addressing climate and energy challenges.

• Advanced Building Techniques : Utilizing state-of-the-art passive building science, the house is designed to optimize energy use, reducing reliance on active heating and cooling systems.
• Sustainable Development : The project sets a precedent for future developments, demonstrating how environmentally responsible buildings can fit seamlessly into urban settings.
• Performance Analysis : Continuous monitoring and analysis ensure that the home performs as intended, achieving significant energy savings over the years.

Impact on Community and Industry:

• Educational Value : This case study serves as a learning tool for builders, developers, and homeowners, showcasing the benefits and feasibility of passive house construction.
• Promoting Change : The project highlights the potential for change in the building industry, urging businesses to adopt sustainable practices.
• Adapting to Climate Challenges : By addressing energy efficiency and sustainability, the house is a proactive response to the city’s evolving climate and energy needs.

Setting a New Standard in Passive House Development

In collaboration with Just Working Construction, the Hayes family’s journey transcends a mere case study in passive house building. It represents a significant stride in redefining what comfortable, sustainable homes can be. From its inception on the drawing board to its completion, this project serves as a beacon of innovation and environmental stewardship.

The Hayes family’s passive house project is more than a home; it’s a testament to what can be achieved when good intentions, innovative technology, and expert execution converge. The results speak volumes about the potential of passive houses as a solution for energy-efficient, comfortable, and sustainable living. This case study stands as a shining example for future developments, striving to make a positive change in the world of residential construction. 

As we unfold the layers of this inspiring project, it becomes evident that this is not just a one-time story. It’s an evolving tale of progress and learning. To truly capture this groundbreaking project’s essence and ongoing developments, we are excited to announce that this feature will be the first in a series of blogs. These blogs will not only delve into the intricate details of the Hayes family’s journey but also offer insights, challenges, and triumphs that come with such an innovative venture.

Interested in partnering with Just Working Construction on a passive home? Reach out and speak with us today.

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Case study: passive house, bessancourt, france.

By Laura Raskin

Architects Milena Karanesheva and Mischa Witzmann’s bamboo-clad passive house in Bessancourt, France, 20 miles northwest of Paris, has lured architectural tourists, locals, film crews, and friends of friends. They’ve come around to marvel at its presence in a town where 12th- and 13th-century structures along dense, narrow streets and courtyards trump modern design. As improbable as the house is, located between a historic district and small residences from the ’70s and ’80s, and as challenging as it was to build, it has helped promote the passive house ethos in a country that has been slower than others in Europe to adopt it.

Published March 1, 2011 Permalink  Citation

(2011, March 1). Case Study: Passive House, Bessancourt, France. Retrieved from https://www.buildinggreen.com/case-study/case-study-passive-house-bessancourt-france

Case Studies in Passive House Design

Passive house design improves the indoor environment and maximizes energy savings..

• By Robyn Friedman, Multi-Housing News

Multifamily residents are more focused than ever on the health and comfort of their interior environments. 

That concern, heightened by COVID-19, has resulted in an increasing number of apartment projects to be designed and built to the Passive House standards promulgated by the Passive House Institute US, a non-profit organization committed to making high-performance passive construction the mainstream market standard.

“Tenants are seeking out these buildings now because they want to live in buildings that have good indoor air quality—and they’re willing to pay more money,” said Katrin Klingenberg, PHIUS executive director. “For a for-profit developer, if people are willing to pay even $50 more a month, that translates into direct value for your building.”

According to PHIUS, passive buildings are designed and built in accordance with the following five principles: Continuous insulation throughout the entire envelope without any thermal bridging, an airtight building envelope that prevents infiltration of outside air and loss of conditioned air, high-performance windows, balanced heat- and moisture-recovery ventilation, and use of a minimal space conditioning system.

Multifamily developers who seek PHIUS certification should expect a cost premium of approximately 0 to 3 percent over the standard Energy Star construction baseline. But the additional cost is returned via significant energy savings. PHIUS buildings perform 60 to 85 percent better than traditional ones in terms of energy consumption, according to PHIUS, making Passive House a viable option for affordable properties as well as luxury.

Since 2011, 73 multifamily projects have achieved PHIUS certification. 

AFFORDABILITY MEETS COMFORTABLE LIVING

Finch Cambridge, Cambridge, Mass.

Finch Cambridge,a 98-unit mixed-income affordable housing project in Cambridge, Mass., provides one- through three-bedroom apartments for very low-income households (under 30 percent of the area median income), low- and moderate-income households (30-80 percent of AMI), and middle-income households (80-100 percent of AMI). It is the largest new construction of 100 percent permanently affordable housing built in Cambridge in 40 years—and the largest multifamily Passive House development in Massachusetts, according to the developer, Homeowners Rehab Inc.

HRI, which has completed net-zero projects and three new-construction developments that were LEED Platinum certified, likes to incorporate sustainability into its developments “to provide healthy housing for our tenants,” said Jane Carbone, HRI’s director of development.

The project incorporates “active design” elements to encourage health and wellness and includes all-electric HVAC systems designed for comfortable living and low utility bills, while the whole-building ventilation system improves health and reduces allergens, with continuous filtered fresh air delivered to each unit.

High-performance, triple-glazed windows offer daylight and fresh air, while exterior shading prevents solar heat gain in the summer months. The result: a 70 percent reduction in energy usage compared to the national average for multifamily housing. Devices track air quality, energy use, water consumption and carbon emissions to constantly monitor the building’s performance.

Finch Cambridge was designed to reflect the wooded areas of the adjacent Fresh Pond Reservation through a treehouse design. Residents are encouraged to use the open stairwell and to take advantage of walking trails nearby. Amenities include a large multipurpose community room and kitchen, resident lounge, study rooms, a rooftop terrace and landscaped outdoor spaces.

HRI worked with NEI General Contracting and ICON Architecture on the $56.7 million development. Construction began in 2018, and the property was ready to welcome tenants in the summer of 2020. “We knew they were the right team,” said Carbone. “Both firms provide much-needed knowledge of Passive House and cutting-edge efficiency standards.”

THE ‘CUTTING-EDGE’ IN ACADEMIC BUILDINGS

Portland Commons, Portland, Maine

The University of Southern Maine recently broke ground on the largest construction project in the school’s history—a $100 million Career & Student Success Center and the adjacent Portland Commons Residence Hall. Both projects are expected to be completed in June 2023. 

The 218,000-square-foot student housing component is designed to Passive House standards and will use 50 percent less energy than a comparable structure built to code. It is the second-largest academic Passive House building and the seventh largest in the U.S. The adjacent CSSC is designed to LEED standards.

“We’ve designed a lot of buildings over the years to meet various energy-efficiency standards, but this is the highest standard we’ve ever aspired to,” said Jeff Jones, a principal of Capstone Development Partners, a national student-housing developer based in Birmingham, Ala., that specializes in on-campus, public-private partnerships. “This is cutting edge.”

The residence hall will have more insulation in the exterior envelope than a typical residential building, Jones said, and the HVAC system will be upgraded to improve indoor air quality. “There are substantial stringent installation policies, procedures and practices that we have to follow, and inspections throughout the construction process to verify that we are doing all we can to provide the energy efficiency that is the driver behind Passive House efficiency and indoor air quality,” he explained.

The residence hall will have 580 beds, a community kitchen, bike storage, laundry rooms and an outdoor courtyard. Jones said that the development team needed to balance the sustainability goal with quality and affordability to keep rents affordable for students.

“New construction is more and more expensive, particularly when you incorporate standards like Passive House,” he said. “The key to the success of this project was that everybody was committed both to the sustainability objective and also to the affordability objective and worked really hard to balance those sometimes-competing goals.”

LUXURY WITH AN EMPHASIS ON HEALTH AND WELLNESS

Solis, Seattle

Located in the heart of Seattle’s Capitol Hill neighborhood, the 45-unit, six-story Solis apartment building uses 70 percent less energy than a typical new building. Solis is currently the largest Passive House multifamily building in Washington.

“It’s a great way to not only reduce your carbon footprint but also to show the world that this is a profitable venture,” said Marc Coluccio, COO of Seattle-based SolTerra, which purchased the project for $4.5 million in 2018 and built it out for a total cost of $24.5 million.

Solis was developed by Cascade Built, a Seattle-based development and contracting firm, which sold the project but remained the general contractor. The design, which includes studios and one- and two-bedroom apartments, is based on Passive House principles to reduce energy use and operational costs and prioritize resident health and wellness. But it’s luxurious as well. 

“The units have some of the nicest finishes of any apartment building I’ve ever been inside,” said Sloan Ritchie, president of Cascade Built. Interior features include engineered wood flooring, quartz countertops and modern cabinetry with matte black hardware, he added. 

Passive House features include an open-air residential lobby and exterior staircase, which reduce heating and cooling loads, continuous filtered fresh air, healthy materials, zero air transfer between units and individual heat pumps.

Common elements include a rooftop deck with views of Mount Rainier and the Seattle skyline, a fire pit and a dog run. There is ground-floor retail as well—a wine and chocolate shop, hair salon and French bakery and café.

Coluccio noted that Solis’ sustainability features helped attract SolTerra to the investment. “This project provides slightly better returns because of the reduced energy costs,” he said. “It’s just amazingly efficient.”

Electric bills for the entire 45,000-square-foot building—apartments and retail—are $700 per month, he added.

Solis has an occupancy rate of 97 percent and asking rents range from $1,850 to $3,800. 

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Case Study: Kāinga Ora Passive House standard

Kāinga Ora's Bader Ventura development reduces energy costs and carbon emissions through the Passive House standard.

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New Zealand's building and construction sector contributes to around 15-20% of New Zealand's overall carbon emissions. It's critical for the construction industry to play a significant part in reducing carbon emissions for the future of Aotearoa New Zealand.

Kāinga Ora - Homes and Communities is tackling this challenge through its Carbon Neutral Housing Programme, including committing to reducing carbon in its residential developments by 2030. One of Kāinga Ora's key carbon reduction projects is its new development, Bader Ventura, located in Māngere, Auckland. It's the state housing provider's first residential development using the Passive House standard.

The Passive House standard is an accreditation that can be used to ensure construction projects have been designed and constructed to maximise energy efficiency. The standard includes criteria for heating, cooling, energy, ventilation, airtightness and thermal comfort.

The Bader Ventura development includes 18 homes in three-storey walk up buildings, which will be 85% cheaper for tenants to cool and heat and will become Australasia's first central government public housing development that meets the Passive House standard.

During construction, Kāinga Ora committed to sharing lessons learnt to support the wider sector in adopting the Passive House standard. This case study is focussed on the design phase, which is now finished, and construction will finish in mid-2023.

Kāinga Ora case study video

Video Transcript

Scene 1 – opening

Construction Sector Accord logo.

Beacon Projects logo.

Text on screen: If New Zealand is to achieve its climate change goals, including new zero carbon by 2050, the building and construction sector must play its part.

Construction work noises.

Music playing – no lyrics.

Shots of Bader Ventura construction site.

Shots of Patrick Dougherty and project team.

Kāinga Ora logo.

Text on screen : Kāinga Ora – Homes and Communities aims to decarbonise all public housing construction activity to low carbon by 2030.

Patrick Dougherty: As the country's largest developer, with a pipeline that's thousands per year for many years to come, there's an opportunity for us to provide leadership.

Brian Berg: Our aspirations are to decarbonize our build program. That's our buildings, also our infrastructure, and other construction activities, in line with Aotearoa's emissions reduction plan.

Shots of construction site, new houses being built and construction materials.

Text on screen: Bader Ventura in Mangere, Auckland is the first Passive House development for Kāinga Ora. The Passive House approach will improve energy efficiency, reduce lifetime embodied carbon, and deliver positive financial and wellbeing outcomes for occupants.

Patrick Dougherty: The cool thing about an occupant's benefit from a passive house, it's only going to cost them a dollar a day to either heat or cool. Per day that is, so that's $365 on average a year to provide all your heating and cooling, which if you talk to any family, they'll understand it's a magnificent difference to what they're currently paying.

Shots of newly built houses.

Brian Berg : A passive house is a building that has been designed to achieve the certified passive house standard. That means it's an emphasis on high levels of insulation in the thermal envelope, which is the walls, the roof, the floors, the windows, and the window frames, an emphasis on air tightness, and then also making sure that we're getting enough high quality fresh outdoor air into that building through a mechanical ventilation system.

Shots of a construction site, construction workers and construction materials.

Rob Moule: While the cost per square meter might be slightly higher than traditional construction, the long-term benefits of a build like this will be huge.

Drone footage of construction site.

Shots of construction work.

Rob Moule: It's so exciting to be able to create change and transform the traditional ways of doing things, and that's one of the things we've looked at as a company. Innovation brings transformation to how we do things, not just the status quo. So the pre-cast concrete that's used here is insulated pre-cast concrete, which isn't often done, but the durability and the lifespan, and the insulation ratings you get from it, are phenomenal.

Shots of construction materials.

Brian Berg: One innovation that I'm personally really proud of on Bader Ventura is the low carbon concrete that we specified in the wall panels. To me, this really shows the concrete industry rising to the challenge to decarbonize construction, and concrete in particular.

Text on screen: Kāinga Ora has committed to continuous reporting of performance and to share learnings with the wider industry.

Jo Charlton: We have to educate, we have to lift, we have to disperse information. We have to take everybody with us.

Shots of project team in a meeting.

Patrick Dougherty: Industry transformation, particularly in the construction sector, is vital. This is an example of providing that leadership. But this is not leadership where Kāinga Ora is showing the way, this is actually us working in partnership with industry to find the way.

Image renders of finished Bader Ventura project.

Rob Moule: I hope the industry's going to look at this project as a beacon, or a landmark project. It's one of Australasia's first apartment building complexes done full passive, and we've had a lot of people stop by already and look at some of the innovations we've been delivering. Hopefully they look at it as a way forward and say, "hey, someone's done it, and it is possible."

Shots of Patrick Dougherty and project team on site.

Shots of team in office.

Patrick Dougherty: Lives are really changed when you have someone who might be living in a cold, damp house and they move into a new one that's got warmth, it's dry, and it's built in an environment that gives them a nice family environment. Lives are being transformed as a result of us improving the quality of what we build.

Scene 3 - closing

In 2020, Kāinga Ora established its Carbon Neutral Housing Programme, which aims to decarbonise public housing construction activity to low carbon by 2030. The programme focuses on three primary areas: reducing operational energy use for customers to have affordable heating and cooling; reducing carbon in building materials and waste; and leading and supporting industry change.

The Carbon Neutral Housing Programme is focussed on how Kāinga Ora can start achieving future government emissions targets using today's technology and how they can bring the industry on this journey. The programme roadmap created a strong foundation for the Kāinga Ora project team to explore different innovations and practices to achieve the Passive House standard during the design phase of Bader Ventura.

The focus of Bader Ventura is to improve overall energy efficiency and to reduce thermal bridging, which can be achieved by designing to the Passive House standard. Thermal bridges are formed when a certain material has a higher heat transfer than surrounding materials. For example, if you have a concrete structure passing through insulation, it will act as a thermal bridge. The problem with thermal bridges is that they are a pathway for heat loss, resulting in a cold home and/or higher heating costs. The cooler internal surface temperature caused by the bridge can also cause condensation on internal surfaces, which contributes to mould growth.

Bader Ventura is a Kāinga Ora pilot project demonstrating the Passive House standard to test whether this certification can help drive energy efficient outcomes in a cost-effective way, and show how it can be replicated across the sector. The decision to build to the Passive House standard was triggered by a conversation between Kāinga Ora's Development Manager and suppliers about thermally broken windows. After realising that these windows were available for around the same cost as standard windows, they discovered that the Passive House standard was a feasible option if the entire project team committed to the idea.

One of the main hurdles was getting the design team on board, as a lot of the design had already been completed and would need to be reworked. There was also resistance in moving away from traditional design and construction processes.

A Passive House consultant joined the team to help with the transition, and Kāinga Ora and the design team worked collaboratively to understand the issues and work through solutions. Unlike other certification standards, Passive House is pass or fail, so there were no partial credits or optional criteria. Early discussions around aiming for the Passive House standard required a high level of trust, expertise and partnership across the project team.

The time and costs involved in gaining the Passive House design endorsement were higher than other projects, partly due to adopting the standard once the design process was already underway. Kāinga Ora expect the benefits to be delivered across the lifetime of the finished building, which is more important than short-term gains from saving money during the construction phase.

The integrated design process to achieve the standard helped the team work together toward a common goal – with building services engineers, architects, Passive House specialists and the construction team all collaborating throughout the process.

Outcomes and benefits

Reducing carbon and improving residents' wellbeing.

Bader Ventura will deliver a reduced operational carbon footprint of more than 70% and reduce heating costs for residents by around 85% (compared to a similar sized dwelling built to a 6 Homestar rating). These significant benefits mean residents will have heating and cooling costs of about $1 per day and will enjoy comfortable year-round temperatures and fresh filtered air.

Enabling industry transformation

Kāinga Ora has committed to continuously reporting its performance and key learnings to the industry throughout the project. The only way to transition to a low emissions future is by working together as a sector and collaborating through multiple channels, such as webinars, site visits, events, reports and more.

MBIE's Building for Climate Change programme was established in 2020 to guide the building and construction sector to achieve its contribution to New Zealand's emissions reduction targets, and make sure our buildings are prepared for changing climate conditions.

The Kāinga Ora Building Roadmap is aligned to policies like these, sets out measures for lower carbon construction and outlines the dates when Kāinga Ora and the wider sector are expected to meet certain targets. Kāinga Ora is aligning its decarbonisation efforts with central government policy to provide evidence to the sector that lower carbon buildings are possible with today's technology.

More information about the Building for Climate Change programme (external link) - mbie.govt.nz

More information about the Kāinga Ora Building Roadmap (external link) - kaingaora.govt.nz

Piloting new approaches to improve productivity

Designing and building to the Passive House standard was more expensive than traditional approaches – mainly because the project team and Kāinga Ora didn't have any experience with the requirements, they had to learn along the way and Passive House standards were added partway through the design process. The learnings and templates from Bader Ventura will be used on future developments to improve productivity and energy efficiency, such as on the Bader Harvard development in Mangere, Auckland.

Lessons learnt

The lessons learnt from the design phase are outlined below. More insights from the construction and post-occupancy phases will be shared by Kāinga Ora once completed.

Identify the environmental standards before starting design

The Passive House standard was added into the design requirements after much of the design work was already complete. It was important for Kāinga Ora to be open to innovation and suggestions from the project team, and ultimately, they found that the standard was the right approach for Bader Ventura. However, it's important to understand the rework, cost and time delays from changing direction during the design phase.

Build a strong team with a passion for environmental outcomes

Designing and building to the Passive House standard requires a different level of commitment, skill and training for the team working on the development, which can seem daunting at the start of a project. There was some resistance from consultants around the level of detail required and considering how to work with the variety of standards and systems.

To overcome this challenge the development team needed to be determined and carefully plan an integrated design process that brought everyone on the collective journey. This involved a series of workshops, meetings and iterations to develop the design. The designers, engineers and builders all worked together to drive specific outcomes to achieve the Passive House standard, such as overcoming thermal bridging issues and ensuring a thermal envelope compliant with the standard.

Project partners

Kāinga Ora also acknowledges the wealth of expertise and assistance provided by its main partners on the project including:

• Precision Construction – building partner
• Peddlethorp – architects
• Oculus Architectural Engineering – passive house lead and façade engineers
• Kirk Roberts – structural engineers
• 2PiR Consulting – building services engineers
• Sustainable Engineering – passive house certifiers  View a series of informative NZ Passive House case studies (external link) .

Many of these companies also have links to helpful resources about Passive House construction on their websites.

Read more information about the Bader Ventura project (external link) - kaingaora.govt.nz

Read our guide on how to implement a similar approach in your business.

© Ministry of Business, Innovation and Employment

https://www.constructionaccord.nz/good-practice/beacon-projects/case-study-kainga-ora-passive-house-standard/ Please note: This content will change over time and can go out of date.

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