In this interview, ZEP Founder Joe Emerson asked Josh Salinger of Birdsmouth Construction about their business decision to focus on high-performance buildings and their latest push into a cluster of zero energy homes.

JE: Who is Birdsmouth Construction?

JS: We are a design-build firm with a focus on high performance building—either zero energy or on the path to zero. Our team of 17 employees focuses on custom residential and small commercial construction in and around Portland, Oregon. Our design side provides full architectural and structural engineering services for high performance buildings at the residential, multifamily, commercial, and institutional levels. It is our goal to lead the construction industry towards zero carbon buildings in order to address climate change through the built environment.


JE: How many zero energy homes have you designed and/or built?

Our first ZE home was the Carlsson project in SW Portland, which we completed in 2015. By the end of 2017, we will have completed four zero energy homes. Plus, we currently have  two more custom zero energy homes in design and are working on a zero energy home development.


JE: What motivated you to begin designing and building zero energy homes?

It’s a long story. It starts with the fact that 47% of all the energy used in the U.S. goes towards our buildings. This is more energy than industry and transportation combined. One can make a large difference in addressing climate change by demanding and creating zero energy buildings. In addition to these homes being zero energy, they also last longer, they are more comfortable, they are healthier for the people that live in them, and they can be absolutely beautiful. Along with all of this, these homes have very low energy bills—therefore addressing affordability at the same time. Building zero energy homes is a win-win-win that motivates our team every day.


JE: Have you built any zero energy developments or multi-family homes?

We are currently in the process of developing Going Street Commons, a zero energy community consisting of 11 certified Passive House homes in NE Portland’s Cully neighborhood. Inspired, designed, and built for a zero energy future, GSC will serve as a model for building durable, comfortable, healthy, and extremely energy efficient homes that respect people, communities, and the built and natural environment. We are really excited to be able to develop this community of homes and be able to offer them at market price. To date, we have reservation agreements for 7 out of the 11 homes.


JE: What is the thing you like best about zero energy homes?

They simply make sense financially and ecologically. They are healthier and more comfortable. These are high-quality buildings that address many of the pitfalls of the way people have been building in the past. Once one has built a zero energy home, one cannot go back. Once one learns how to do something right, the results speak for themselves. A reasonable person cannot build ‘bad’ buildings after having built a zero energy home. There are no sacrifices with these buildings. Zero energy homes perform better for their occupants than typical buildings, period. And when done right, they cost less to own.


JE: What have you learned about designing/building cost-effective zero energy homes so they are affordable?

It starts at design. Not just schematic design, but even before one lays a pencil to paper. If one’s goal is zero energy from the onset it will guide one’s decisions throughout the whole process, from the first meeting through construction. The acronym K.I.S.S. (Keep It Simple, Stupid) should be one’s guiding light. Simplicity can be beautiful—think of a country song. As soon as one finds oneself fussing over an origami-like detail, zoom out and think about how it could be simplified. Oftentimes, the answer isn’t that complicated. Also, having an experienced and educated staff and an informed and committed base of subcontractors can streamline the build process and produce zero energy homes cost effectively.


JE: What design details are most important to strong energy performance?

Pay attention to the air barrier. Draw it on the plans – preferably in a different color. We create an ‘Air Barrier’ details set, called ‘Detail AB.1, top plate to bottom of rafter detail’. One should be able to put one’s pencil down on a building cross section and draw a continuous line around the entire building without lifting up the pencil. Talk through the air barrier strategy with the project manager and site supervisor prior to construction. Listen to their input – constructability matters in terms of cost, time and effectiveness. Model your projects prior to building with a robust energy design program such as PHPP, Wufi Passive, or REM/Rate. Plan your mechanical, electrical, and plumbing and have all the layouts plotted prior to construction. Ultimately, pay attention, do good work and importantly, test as you go.


JE: What have you learned about how to keep costs down?

Use the local trade vernacular whenever possible. Trying to teach old dogs new tricks doesn’t tend to lend itself to cost savings. Here are a few examples of going with the flow of materials and workers instead of swimming against the current. Don’t harp on the framer to pull every errant nail and then try to track down all the holes. Instead, use a self adhered membrane and simply cover up these leaks. Pay attention to the context. Is it the rainy season when the air barrier is going on? Use liquid-applied membranes. Does the house have a simple shape? Use tapes. Does the site supervisor on this building have a lot of experience installing the windows with clips? Use clips. Try and cut out unnecessary steps and materials by, for example, using advanced framing or off-the-shelf materials. Consider materials that have multiple functions such as sheet goods that act as an air barrier, weather barrier, vapor control layer and the structural sheathing. Simplify plumbing runs. Use a simple wall assembly over and over so you build up muscle memory in the staff and subs. Leverage economies of scale if possible. Set budgets for items in your projects and ask your suppliers and subs how they can help you meet them. It’s surprising how many great ideas sprout up from this simple request.

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Josh Salinger, CEO and Founder, Birdsmouth Construction

JE: Are there any new technologies for reaching zero energy cost effectively that you are excited about?

We have been eyeing the ‘magic box’ HVAC systems that are on the horizon. Systems such as the Minotair or CERV can heat and cool, provide filtered air, balanced ventilation, and control humidity all in one system. One set of ducts to install and all in a small system with no exterior unit. This technology is exciting as it essentially costs about the same as a traditional furnace in a code home, but provides all of this and more in a extremely efficient manner. The Minotair brags of COP’s of 3 or more in heat pump mode.


Often water heating is the largest drain on the energy budget, and the new CO2 split heat pump water heaters, such as the Sanden, sip energy with a COP of up to 5. It can really perform well without affecting the temperature or latent loads in the home. An added advantage is that the CO2 used in the Sanden has a considerably lower carbon footprint than the refrigerants in most heat pump water heaters.


JE: What advice would you give a client beginning the process of looking for and buying a zero energy home?

Choose your project team early on. Get the architect, engineer, and builder working together from the onset. Way too often we see fully formed schematic designs that, technically, could be shoehorned into ZE, but at what cost? If only the architect had initially consulted with an experienced zero energy builder a lot of the complexities could have been avoided and, likely, the end product would have been better. Also, be direct and open about your budget. A good team will know what the budget goal is and work with the client towards delivering the program goals within their budget.


JE: How would you advise designers and builders to reduce construction costs?

Work in an iterative process. Get product and material information, along with the cost and constructability aspects from the builder and incorporate it in the design, then do it all over again. Listen to one another and don’t be obstinate. Keep an open mind and an eye on the ultimate goal. Size your mechanical systems based on the energy model. Specify fixed windows wherever operating windows aren’t needed. Use simple wall assemblies and foundations. Use the inherent beauty of construction materials to one’s advantage, for example, use the concrete slab as the finished floor. It can be beautiful, and if someone desires to cover it in the future, it’s easily done.


JE: What was your experience with the financing and appraisal processes of zero energy homes you have sold? Do you have any suggestions for other builders?

We have found, in general, most real estate agents, appraisers, and banks tend not to value the true benefits of zero energy homes. That said, things are changing and we have been able to locate accredited green appraisers and brokers in our area. Also, downloading and filling out the ‘Residential Green and Energy Efficient Addendum’ from the Appraisal Institute and providing this to your lender/appraiser/broker helps them understand and value the benefits of ZE homes. One does have the right to choose a different appraiser when asking for a appraisal. Make sure you are getting a trained professional who knows how to properly value these homes.


JE: Did you receive a third-party certification? If so, how important was that in your process?

Yes, we certify all of our homes to Earth Advantage Net Zero, PHI, and/or PHIUS+ certification. One benefit of certification is the third-party blower door test. It verifies our homes before and during the process and allows our clients to know that we are building like we say we do. The precertification process, specifically the Passive House computer modeling, helps us determine exactly how much insulation we need or how much performance we need from our windows. We can size systems appropriately and not oversize them. We can orient the home to its specific geo-location and size the overhangs so we can avoid overheating or cold spots. By playing with the locations, dimensions, sizes, and position of the windows in the wall assembly we can really tune the design so we can make sure we are being as efficient from a cost and performance perspective as possible. The third-party certification also helps us market our homes and stand above the fray. Studies have shown that certified homes also bring a sales premium over similar, non certified homes.


JE: Do you live in a zero energy home? What do you like about it?

I don’t. Mostly I just bemoan the energy inefficiency of my 1925 bungalow and follow my kids around turning off the lights after them. We did install a Sanden CO2 heat pump water heater after our old water heater broke down, and I also installed exterior blinds on the West upper windows of our home. I can’t wait to replace the windows, tear off the siding, install exterior insulation, work on the air barrier…


JE: What policies are needed to advance the movement toward zero energy building as standard practice in the construction industry?

Currently, I think the fight is not at the federal level. With climate change denying politicians in charge of the USDOE ,we can’t expect to see change as rapidly as is needed. The saving grace is that large strides can be made at the state, county, and city levels. For example, in Vancouver BC, all governmental and affordable housing is required to meet the Passive House standard. This is something to try and emulate here in the U.S. Also, if we can show built examples of  zero energy housing for less-advantaged communities, it will show proof-of-concept that should answer any skeptic’s criticisms against a zero carbon energy code. Additionally, states need to adopt the IRC energy code cycle change every three years.
Builders would be encouraged by incentives for high efficiency construction. Locally, we should be lobbying for policies, such as incentivizing floor area ratio (FAR) increases, adjustments to height restrictions, or setback requirements for buildings that meet a high level green certification such as zero energy or Passive House. In some areas builders are allowed to build more densely. More units on a given site allows them to recover the extra up-front construction cost by selling more units. These are things many local jurisdictions can do without running afoul of most current state statutes. Other programs aimed at utilities such as the Metered Energy Efficiency Transaction Structure (MEETS) program that allow developers to reap the financial savings of additional energy upgrades while at the same time allowing the utility to remain whole should be pursued. Other items such as incentives and challenges such as the 20×2020 building challenge should be considered locally.