TL;DR
This month, I’ll admit that I went down a rabbit hole on different sustainability programs, and I’m taking you along for the journey with me. While there is a lot of information below, the short story is that there are many programs that can help a design team, contractor, and owner build a better home. What is essential is choosing the right program for the given set of goals. Also, keep in mind that a reasonable goal may be to combine programs that fulfill partial goals, such as designing to Passivehaus while attempting to source low carbon or carbon sequestering alternatives for common materials.
As an ever changing and charged conversation, I would also be very interested to hear your thoughts on this topic if you’d like to email me or give me a call.
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A few months ago, I wrote a newsletter about the Pretty Good House. This non-standard-standard offers a good – if lackadaisical – approach to building better, but there is still plenty of room to consider the gold standard programs that we have available. But, how do they compare and which may be best for a given owner or project?
As I began writing this, I attempted to create a table of the different methodologies and their requirements. Reality sunk in as I realized that each method approaches the concept of sustainability with different goals, and as such has a totally different way of measuring success. An easy to digest table is simply impossible to reconcile with the differing requirements. So, instead I will briefly discuss each and their method. For simplicity, not all requirements of each program are represented here. It would likely require a PhD dissertation level analysis to fully break down all the programs with full comparisons, and our goal today is to have a basic understanding to help our clients navigate which program may be best for their goals.
Very few of the programs available seek to understand or mitigate the embodied carbon in building materials. Indeed, on this list only the Living Building Challenge has a component that addresses this aspect. While some high embodied carbon materials – like aluminum – can be avoided by designers, for holistic sustainability many aspects must be considered and it may be that many years of industry change will be required to address this issue.
I will also note that this list is not conclusive. There are other programs that may have merit and add value to a project. I specifically excluded a few European standards, for instance.
Energy Star 3.1:
Released by Energystar.gov, this program is an easy to follow sets of rules that can achieve a somewhat better than code building with a really minimal effort. A blower door test result of ACH50: 3.0 is expected. Where a home built to code standard may achieve an ACH50 of ~7.0 this still represents a significant uplift in quality. Even though the effort this standard requires is minimal this still represents something better, and that is to be applauded. I have seen this applied on production quality homes, but do not expect it would meet the high quality expected of high-end clients.
Passivhaus Institutes’ Passivhaus
The true poster child of sustainable home building, Passivhaus was first introduced in Europe in the 1970’s. This standard seeks to utilize existing building materials and systems to achieve 90% reduction in total energy use. A blower door test must result in ACH50 of 0.6 or less to be considered a success. While this standard is difficult to achieve without significant effort and requires successful deployment of many passive energy strategies it does not seek to reduce carbon emissions or reach net zero. Thus, it only looks at part of the whole problem of sustainability.
International Living Future Institute’s Living Building Program
This standard is a holistic, if onerous, view of how to build sustainably. Currently in its 7th iteration, it describes 7 ‘petals’ across the 541 page manual that are required to complete the challenge. Place, Water, Energy, Health+Happiness, Equity, and Beauty. The standard requires demonstration of results over a 12 month period so results are actual rather than assumed or modeled. As the LVB is billed as being for any building type – or a park – it is very difficult to recommend to a homeowner as the requirements are obtuse, if I am being generous. Even so, the holistic approach to the various parts of a building in its construction and use are laudable.
International Living Future Zero Carbon Certification
This program tackles both operational and embodied carbon. Like the Living Building program, results must be demonstrated after a 12 month service period. It can be considered as a subsidiary part of the Living Building Challenge as that standard references this one as one of it’s 7 ‘petals’. However, taken alone, it offers guidance on building to a zero carbon standard. It does this by requiring primary materials (foundation, structure, and enclosure only) chosen to be a % lower than the industry baseline. By itself this is not very aggressive and may have limited impact. Consider this is combination with the reliance on use of carbon offsets (often considered a rob-Peter-to-pay-Paul level of policy failure) to reach Zero Carbon, and this program may offer limited success. It is worth considering that many of the common and integral building products we use regularly do not have low carbon or carbon sequestering alternatives. This limits our choices in this arena and hampers efforts.
Department of Energy’s (DOE) Net Zero Energy Building (NZEB) program
This program is geared towards buildings other than homes and they direct you to a slightly different program called the Zero Energy Ready Home Program. The program seeks to create a building that is energy efficient enough that IF renewable energy systems were added that it would be Net Zero. As with Passivehaus, this program does not consider the materials that go into building or the carbon emissions during building use, only the energy expenditure. This standard is verified by software modeling and inspections during construction as opposed to reviewing real world usage after 12 months like the LVB above. Interestingly, meeting the requirements of the above Energy Star standard is one of the components of this program, though it goes much further. Since this standard only seeks to be net zero ready it is not recommended for any client with holistic interest in sustainability, but may meet the needs of clients looking to reduce their energy use alone.
USGBC LEED (Leadership in Energy and Environmental Design)
Attempts to “…drive the market towards a near-zero carbon reality…” A laudable goal that has stalled somewhat in execution. After many years of complaints that LEED accreditation is a game where reports of project teams including nonsensical items in designs just to get LEED points for the accreditation are common, I find it hard to recommend this standard to anyone. Especially in the residential space. More than anything I find that the only purpose in getting LEED for a building is as a marketing piece, and therefore only worthwhile for commercial enterprises. Even so, following the guidance can lead to far better buildings. And, this can be done without going to the effort or expense of getting the badge, forestalling any gamifying of the points system. Points in favor of LEED are that requirements address indoor air quality, energy use, natural light, reduced water use, and use of safe building materials. Energy savings may be up to 60% as opposed to the 90% savings promised by Passivehaus.
Perkins and Will Precautionary, Watch, and Sunset Lists
The Architecture Firm Perkins and Will publishes lists of chemicals that they do not recommend using across any of the building materials you may use in construction of a home. On the Precautionary List we see many common chemicals used in many different products. These are known threats to human health and are not recommended for use. The Watch list are chemicals or concern, but appropriate alternatives are not yet available or data is inconclusive. The Sunset list shows chemicals that are of concern but have been removed from the majority of products already by the industry either from government action, or otherwise. While I applaud Perkins and Will for offering this resource to the wider design and construction industry it is apparent that attempting to apply this list as a Red List against any products for use in a project would be a daunting task. Clients with significant interest in Indoor Air Quality and long term health impacts from contaminant exposure may be most drawn to this information. The use of a tool like 2050-materials.com may be a good way to find materials that preclude Precautionary List chemicals without all the leg work (Perkins and Will and this website have no affiliation).