Hi, Dale here. It’s been a couple of months; welcome back again!
This post is aimed at those of you who are architects, builders, and skilled tradespersons. We’ll take a deep dive into Phius certifications (Passive House Institute US) with a focus on single family homes. (Phius standards can be applied to multifamily and commercial buildings too; I may post more on them in the future.) This post is a bit longer, with lots of links to materials I found over the last few months.
First a quick refresher: Passive House is the gold standard for building energy efficiency. Phius has created building envelope standards (insulation, airtightness, and vapor control) that are cost-optimized for all climate zones in North America (and beyond). The result is a building that requires 75-90% less energy to heat and cool than most buildings and produces savings that pay back the additional envelope cost over time. If you have not seen this introductory video before, it is well worth 4 minutes of your time: Passive House 101 Explained in Under 4 Minutes.
- This TEDx talk spells out the benefits of Passive House which you can promote to your clients. The UK-based speaker sums it up as “Virtuous Luxury.” While I prefer to refer to our homes as “high performance, superbly durable, and extraordinarily healthy,” the talk is a great model for how to promote the value of Passive House to the building owner and the public. (MiNet0 designs aim for lagom, not luxury, along with quality, innovation, and sustainability.)
For professionals designing and building single family homes, Phius offers several rigorous certifications:
- For architects and building engineers, it’s the CPHC certification (Certified Passive House Consultant):
- I obtained my CPHC certification in a class of 15 architects and 3 engineers who had HVAC/mechanical systems background like myself. I was on a team with two architects which was super helpful because they could quickly render a building in 3D CAD. My strength was the number crunching on HVAC/DHW energy use and assembly R-values needed for our in-class project.
- In total, obtaining the certification will require $2100 and
- a few weeks to watch the independent online training totaling 50-60 hours.
- 24 hours of live training over two weeks (including a team project).
- time to study for and take a challenging, calculation-heavy online exam.
- more time to submit a complete drawing package meeting Phius requirements for an assigned hypothetical project. This was challenging for me with my fledgling 3D CAD skills. Phius does accept hand sketches for some of the details.
- You can apply here.
- For builders, it’s the CPHB certification (Certified Passive House Builder):
- I know of only one CPHB in West Michigan. We need more! In fact, I want to either partner with a builder who obtains this certification, and/or hire someone who obtains this certification to be the lead carpenter on my sites.
- You can apply here for upcoming virtual training starting January 16 (for two weeks) and again on March 20: Browse All Events | Phius
- For a house to be Phius certified, an independent 3rd party rater must be involved in the project’s design, construction, and final inspection phases.
- Residential raters can apply for two-day, in-person training in Boston starting March 21.
- Commercial verifiers can apply for two-day, in-person training in Boston starting January 25.
- These services would be excellent additions to businesses that already do HERs ratings, LEED or Greenstar certification, and/or other building performance testing. Again, we need at least one in West Michigan!
- We also need skilled trades gearing up to support this work:
- Carpenters will need to learn some new air-sealing skills, which is arguably even more important than the finish-carpentry. On a passive house jobsite, nobody penetrates the envelope without an approved plan for reliable air-sealing and a signoff that’s it’s been done correctly!
- Insulators will need equipment and training to do a high-quality job of dense-packing cellulose insulation into thick, open wall and roof cavities. (Wet-applied cellulose is NOT allowed in thick assemblies!)
- HVAC contractors will need training to install and start low-ambient heat pumps and high performance ERVs. Once trained, there’s no reason a low ambient heat pump should require more labor to install than a cooling-only system (although the unit will cost more).
- Plumbing contractors should be familiar with EPA WaterSense and trained to put in heat pump water heaters. Again, there’s no labor addition here vs an old-fashioned electric water heater.
- Electrical/solar contractors are needed who can design and install an integrated system with a smart electrical panel, a solar array, a battery storage system, a bi-directional EV charger, the heat pumps including a condensing dryer, and the induction stove. There is some additional design and installation work for the power and storage systems, but everything else is normal. Look at it as an addition to your scope of work. There’s no better time to add the “power plant” to the house than right up front!
- All finishes are sourced for low embodied carbon and health, but otherwise they install normally. (OK, maybe some new zero-VOC adhesives, paints, etc., but an Energy Star appliance plugs in just like any other appliance.)
- Everyone will need some training/orientation to the special requirements of the building and site, all of which will be documented in the plans, so pay even more attention to the details than usual!
For the house itself, Phius offers two paths to certification:
- The prescriptive path is less costly (~$700 plus CPHC fees of say $10,000 and rater fees of $5-10,000) but will constrain the footprint of the building to a “compactness ratio” of envelope to floor area.
- The performance path (~$1700 plus CPHC fees of say $15-20,000 and rater fees of $8-15,000) allows more design flexibility but requires a WUFI energy performance model.
- Notes
- When I first started thinking about building net zero houses back in 2020, I was hesitant to seek certification because of the additional costs and time required. However, I’ve come to see the support and roadmap offered by Phius as indispensable. It’s not easy to change course and build better within a construction community that has so much status quo inertia. Phius (and Greenstar and LEED and BEAM) have helped me clarify both the vision and the details needed to produce a comprehensively net zero design that is build-able with obtainable materials.
- New houses can be certified either to Phius Core or, with the addition of onsite renewable energy, to Phius Zero.
- Existing homes can be certified under the Phius Revive program. (Retrofits are in many ways more difficult than new construction, so I opted to start with new construction, and specifically with a spec house because that gives me complete control of the variables. My goal is to perfect the recipe first before offering more general services to the public.)
- Notes
Overview of the process, for architects/CPHCs in particular:
- Here’s a great overview of the design and certification process by two architects/CPHCs, Tom Boeman and Curtis Stewart, from the Phius Alliance, Chicago Chapter.
- Here’s another more design-oriented webinar by Tessa Bradley, a principal architect with the Artisans Group in the Olympia, WA area.
- PSA: For architects and developers of high-performance buildings of any size, you are invited to join us for this virtual conference: (47) Join us for Reimagine Buildings ’24 on March 7-8, 2024 – YouTube
In summary, Phius offers a road map to cost-optimized, verified performance. It is rigorous, but as Jack Semke says in the 4-minute video, Passive House is more of an evolution than a revolution in building design and construction. Anyone with an aptitude for building science, a willingness to learn, and a desire to build a better future is encouraged to obtain the certifications and begin offering these upgraded services. Our world needs you!
Future blogs I’m working on include:
- The financials of MiNet0-1
- Phius for multifamily (as mentioned)
- Let me know if you have a topic you’d like to see me cover.
To close, thank you again for engaging! I invite you to bookmark our blog and follow me on LinkedIn.
