We’ve written a lot about why Passive House is the next big thing in construction, and simply put, actually building one takes a very different process than is typical in American construction. This post is about what design and construction will look like in the future, and how that can result in better buildings for everyone.
Certified Passive House buildings, or buildings that aim to be “net-zero” have very well defined targets for success and the targets are very demanding to hit. A net zero building produces as much energy as it consumes- you know if you are successful at the end of the year based on whether or not you had to pay the utility company anything at all. A certified Passive House is required to meet 3 critical performance numbers: one for heating and cooling energy, one for total energy consumption, and one for air tightness. It can be very difficult for contractors to be certain that their buildings will meet these kinds of goals prior to construction, and incredibly expensive to address any issues once construction is complete. We’ve seen over 100 certified Passive Houses built in the United States, and over 20,000 buildings in Europe. How does this work?
The fundamental difference in creating a high performance building that really delivers as advertised is in the collective responsibility for performance. Each high performance building is a system in which the functionality of each component is interdependent on other components to function correctly. Architectural form, framing, insulation, and other system components all effect one another in their performance, so the parties responsible for each element all have a stake in the performance of each others components. Each of these systems in turn affect cost both up and down. Getting it right is a delicate balance of performance, design intention, aesthetics, and craftsmanship that requires true professionals in all of the design professionals, consultants, and contractors who are involved. Recently various professional industries have latched onto this idea and it is generally described as integrated project design (or sometimes integrated project delivery). In construction however, this is not just about the design on paper. Delivering high performance projects requires integrated contracting. This is what we call our approach, and it seems to work exceptionally well.
While the coordination of professional trades and consultants can sound complicated, the shift in mentality and responsibility is really only big change. Much of the work can still be done by subcontractors with specialized knowledge of each field. When the understanding of relationships between building components and systems increases, performance increases drastically. Doing this requires an educated and invested workforce, and team members that are dedicated to open, clear communication. The traditional linear process commodifies construction into discrete parts to optimize for lowest cost. The integrated process ties elements together to capture synergies between elements and optimize performance. Interestingly enough, this also results in reduced cost and improved comfort.
When we did the Strand-Pfirman house in Whitefish, we were brought on as a subcontractor early in the design process. The architect and general contractor collaborated extensively to ensure that the form, size, and layout of the building fit the functional and budgetary goals. We were offered the opportunity to make recommendations about form, size, and layout that would reduce the cost of the HVAC and insulation systems. The shape of the house was optimized to reduce insulation costs, allowing us to provide a thicker wall for the same amount of money. We performed multiple heat load calculations to determine the most efficient heating equipment size based on the thicker walls and the selection of windows. The result: the owners took occupancy in February and tracked the energy they used for heating only. They paid $7 the first month, and $4 in March.
Another example was on the Cravy project we’ve been working on this summer. We substantially increased the usability and real estate value of the property by finishing the basement into three additional bedrooms and a full bathroom. We also fully insulated the space with R25 walls and high performance Alpen windows. Careful coordination with the plumber and the architect in planning the space allowed us to fit a forced air heating system into each room. The result is a more comfortable, usable basement that also costs less because the entire house is served by a single mechanical system.
One of the most important pieces of feedback we’ve received about integrated design and construction is our clients are happier. They understand what’s going on, and they like seeing contractors, architects, and other consultants collaborate. Plus, the process is a lot more fun, and a lot less stressful. When everyone understands their stake in the project outcome, every team member gets motivated to do their best work. Mutual respect fosters a collaborative, exciting atmosphere, and the quality of the entire project gets elevated. Integrated design offers a better deal for owners, consultants, contractors, and the only way to deliver truly high performance projects.