An Architect’s Guide To: Designing Your First Passive House

Michael Ingui is a partner at Baxt Ingui Architects and the founder of Passive House Accelerator. The Accelerator is a catalyst for zero-carbon building and a collaborative media platform for practitioners, developers, and manufacturers working to create better buildings through Passive House design and construction.

Passive House is a hot topic in the architecture community, especially as conversations around energy usage gain increasing urgency worldwide. Have you ever wondered why clients are now seeking Passive Houses in larger numbers? Have you ever wanted to design a house to Passive House standards but didn’t know where to start?

Passive houses are well-sealed, well-insulated, thermal bridge-free buildings with filtered, fresh air 24/7. This allows a Passive House to require almost no heat in places like New York City, and significantly less cooling (especially when taking shading into account).

Passive house construction and high-performance windows and doors in this townhouse addition allowed us to create walls of glass with an indoor-outdoor experience to a roof deck clear of all mechanicals. Also interesting is that this house requires almost no heat, even in this space. Photos by Peter Peirce, Inc.

Many of our clients come to us seeking a high level of design and simply the best home they can have. Part of our portfolio are townhouse and brownstone renovations and additions, many of which are in landmark protected historic districts. We have found that our clients obtain the highest quality building and the amenities they want is through Passive House design.

Our clients typically know what they want when it comes to design: large expanses of glass, smaller mechanical systems at convenient locations, and healthy, serene environments that create spaces in which they are excited to live. However, there are other things that they don’t know are possible, so they don’t ask for them. For example, they don’t know they can have a house that is relatively bug-free, sealed from almost all outside dust, supplied with filtered, fresh air 24/7 and capable of staying warm all winter without the need to turn on the heat. Once they know these things are possible, they can’t live without them.

Focusing on the incredible amenities of Passive House rather than the methodology of getting there is how we get so many clients to do Passive House. Before Passive House, we never discussed the ins and outs of how we heated and cooled their homes, and there’s still no reason to do it today. People want the best house they can have, and designing to Passive House is a great way to get them there.

Many of our projects are in landmarked districts in New York City. This simulated double-hung window system looks incredibly similar to the double hung windows on either side yet performs so well that the heating and cooling is delivered through a small grill at the opposite end of the room. There are no visible differences between the passive houses we do and a typical house, but the sound the door makes when it closes, serenity inside, and noticeably filtered air immediately tells you you’re in a better built home. Photos by Peter Peirce, Inc.

Even in New York City, the Passive Houses we’ve completed require almost no heat. As a designer, imagine not needing a boiler, radiators or other systems because the house has been so well insulated. This makes smaller heat pump mini-splits, which take up minimal space and can be located far away from windows, effective. Shifting mechanicals away from windows also provides great design opportunities.

There are several tips and tricks that allow us to make our Passive projects as successful as possible.

First, we bring in Passive House consultants early in schematic design. This ensures that while we design, we keep important performance measures in mind. With their help, we’ve been able to create large expanses of glass on some façades, and less on others, and they’ve also helped let us know where shading is needed. Passive House consultants can provide a sense of where mechanicals can be placed, informing design decisions and creating interesting possibilities. Including your consultant in design and detailing early de-risks not only your first Passive House, but also every one thereafter. This prevents working backwards, keeping costs down and satisfaction up!

We have used the performance level of Passive House windows and doors along with the freedom from needing heating at the windows to create interesting spatial relationships between levels in ways that would have been very difficult otherwise. In this home, we removed a portion of the parlor level, allowing the garden kitchen-dining area to communicate seamlessly with the living room and outdoor terrace, which is accessed through the bridge above. Photos by Peter Peirce, Inc.

We also include general contractors as early as possible. Our office has worked this way for years, bringing in contractors after schematic design and working with them to develop details, mechanical strategies and structural strategies. This process enables better detailing and reveals design opportunities early in the process.

We are often asked how to find Passive House certified contractors. Typically, we actually just use the contractors we’ve known for years. As long as your contractor loves building, they can learn how to do a Passive House easily. There are a number of contractor training courses available, and the community of contractors and craftspeople familiar with Passive House is constantly growing. Once they take contractor training, contractors should host kickoff meetings with subcontractors to ensure that everyone knows what the goals are.

Many of our contractors utilize Passive House consultants during construction to de-risk implementation of tricky details. Bringing in the consultant early, bringing on a contractor early, and having consultants and contractors collaborate during building are three key moves that allow architects to focus on design instead of troubleshooting problems. This, in turn, keeps the budget and schedule in check.

The benefits of designing a Passive House don’t stop at the interior. What would have been four or more exterior A/C units are now very often only one unit, and this unit is typically small, quiet, and can often be wall-hung. These Mitsubishi Citi Multi heat pump units MEET THE BUILDING’S ENTIRE LOAD. Reclaiming roofs allow us to create outdoor living rooms, complete with almost any amenity the client desires. Left photo by Mike Tauber; Right photo by Baxt Ingui Architects.

During our first Passive House projects, we learned a number of important lessons that we feel every designer should keep in mind:

• Proper shading is imperative to maximize performance of large windows.
• A systematic approach from start to finish is key.
• Weekly meetings keep all members of the project team informed and on track.
• Utilizing the blower door as a tool during construction, not just a test at the end, prevents contractors from working backwards to find leaks in finished projects.
• Adding the blower door into the commissioning process at the end of a project, alongside confirming air flow, balancing mechanicals and teaching clients how to care for their homes has been essential to completing projects and keeping clients happy for years to come.
• For those unfamiliar with a blower door test, it is simply a nylon door with a fan that allows you to pressurize and depressurize a house to determine how well-sealed it is.
• Passive House has allowed us to create homes with large amounts of glass, massive skylights and layouts free of annoying mechanicals. It has certainly created more satisfied clients!

Once you’ve created a better building through Passive House, you can start to consider renewables like solar. In this project, we were able to create a canopy system that helped to shield a large multi-panel door system from the sun and rain. Photos by John Muggenborg. 

Creating your first Passive House can be fun and rewarding for designer and client alike. It can create a healthy, serene, and comfortable indoor environment and, if you follow a systematic approach, it can be completed in a cost-effective manner.

To learn more about embarking on your first Passive House, look here: 10 Steps to Designing Your First Passive House | Passive House Accelerator.

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