By Michael Ingui

This article was originally published on Green Building Advisor. To check out the original, click here.

Over a decade ago, I was working on a townhouse renovation next door to a Passive House renovation led by contractor Sam McAfee. Both projects were beautiful single-family townhouses in Brooklyn, N.Y.

My clients were incredibly happy with their house. It operated effortlessly, with an elaborate control system that allowed the 14 tons of cooling, radiators and in-floor heating zoned for every space, humidification and dehumidification, and 16 thermostats to be controlled in one interface.

The Passive House project looked similar to ours, but it ran on one small heat-pump heating and cooling system, included fresh air 24/7 via an energy recovery ventilator (ERV), and its windows blocked most street noise. Their HVAC required far less ductwork, and there was no boiler, no flue, no massive manifold setup, and no redundant thermostats or sensors. The controls were incredibly simple, and the house simply felt better. We immediately started to collaborate with Sam as our Passive House consultant, and it changed the way we work. We embarked on Ingui Architecture’s first Passive House–certified townhouse, also the first in Manhattan. While our firm focuses on high-end residential work, Passive House and passive measures can be used for many different project types, including multifamily, affordable housing, and commercial construction.

What Is Passive House?

Before diving into our history of Passive House construction, it’s worth defining Passive House and explaining how we use Passive House principles as a design tool.

Fundamentally, a Passive House is just a better-built building. By investing in

• super-insulated envelopes,

• airtight construction,

• thermal bridge-free detailing,

• heat-recovery ventilation, and

• high-performance glazing,

you end up with a house that uses less energy, resulting in happier and healthier occupants.

Although the five principles of Passive House listed above are the practical tools needed for success, very few clients ask for those things. Explaining Passive House strategies alone is rarely enough to convince a client. Instead, we tell clients that Passive Houses are incredibly quiet, serene, and secure; free of most bugs, dust, and outside allergens; resilient in extreme weather and able to hold their temperature longer; and deliver filtered fresh air 24/7. The highest-cost investments, airtightness, and an ERV system become no-brainers once clients understand the benefits those investments provide.

Passive Measures

Often certification is not right for a project—budget, scope, or consideration of historic details can make it impractical. Regardless, we apply the same systematic approach to Passive House measures on both certified and noncertified projects. In most cases, those measures significantly reduce heating and cooling loads and create healthier indoor environments.

Since our first foray into Passive House, our office has completed over a dozen certified Passive Houses, many noncertified passive projects, and even more renovations that have benefited from passive measures. We learned quickly that unless we had a repeatable, systematic approach, neither clients nor contractors would embrace it. We developed our approach over the next few years and have been refining it ever since.

The first meeting included a few construction firm owners, our team and Passive House Consultants, and Kevin Brennan, our airtightness and insulation subcontractor and a Passive House Tradesperson instructor. Many had competed for years; few had met.

The first meeting started as awkwardly as one might expect. But by the end, everyone was sharing photos and had made pages of notes on how to improve details. The second meeting drew nearly 20 people, including engineers and other architects, and was moved to the afternoon so that it could be followed by a happy hour. Now the Contractor Collective meetings have 40 to 50 attendees, and many contractors speak between meetings. With each meeting, we refined sequencing and product preferences, and we updated and improved details. This level of collaboration and community building is key to successfully scaling Passive House, both locally and broadly. These Collectives were one of the inspirations for what is now the Passive House Accelerator and Reimagine Buildings Collective.

Assurance of healthy indoor air is another benefit that Passive House and passive measures offer. This became clear to many of our clients in 2023, when wildfire smoke from the Canada fires caused the air quality in New York City to drop to levels not seen since the 1960s. At the time, one of our clients had recently moved into his Passive House and was monitoring both energy usage and air quality in his new home. He found that “in the house, the air quality meters I had just gotten showed that during the fires, the air quality was exponentially better inside than outside.” Another former client family, living in a Brooklyn Heights Passive House with their young son, told us their favorite aspect of living in a Passive House was the “peace of mind knowing that our family is insulated from pollution.”

As I’ve said many times before, the only people not employing passive measures are those who simply don’t know it exists. Using the certification framework, regardless of whether you intend to certify your project, provides a road map and a checklist for success. Certification, when appropriate, gives the added benefit of including a third party who can be used as a tool during the project. Often the team of certifiers at the certifying body is integral to managing the most difficult challenges faced during the project.

A Systematic Approach to Passive Measures

In future articles, I’ll dive into our systematic approach step by step, exploring the best practices employed by our office, other architects, builders, and consultants to successfully complete Passive Houses:

• Defining the “why”: comfort, health, resilience, and performance

• Design first, performance always

• Building the team early

• Model before you build

• Making airtightness approachable

• Windows and ventilation strategies

• Perfecting the details

• Testing, verifying, and monitoring

• Teaching clients and reflecting every time

One of the best aspects of the high-performance building community is the level of collaboration among practitioners and a long history of openly sharing problems and solutions. Publications like Green Building Advisor and Fine Homebuilding, and resources like Building Science Corp., Passive House Accelerator, Reimagine Buildings Collective, BS* + Beer, Building Science Symposium, and more have already accelerated the construction of high-performance buildings. We are lucky to be in an exciting emerging market where better building and happier clients create a win-win for everyone.

Top photo by Adam Kane Macchia.