Many of our clients who want to build an environmentally exemplary project have asked which certification path would be best: LEED, Phius, Living Building Challenge (LBC), or Zero Energy Ready Home (ZERH). This post explains the features, advantages, and differences between these paths.
Comprehensive vs. Energy-Focused
The first delineation is between comprehensive programs like LEED and LBC and energy-focused programs like Phius and ZERH. Comprehensive programs have a wider scope, attempting to consider most or all of the important aspects of a building’s impact. Energy-focused programs, as you’ve guessed, primarily require energy efficiency, though they consider more than just BTUs. Here’s a bit about each program:
1. LEED
LEED uses a checklist to score a building’s sustainability features. The categories are Location and Transportation, Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, and two more customizable categories, Innovation and Regional Priority. As you can see, to score highly, a building must address a wide range of issues. The project is ranked Certified, Silver, Gold, or Platinum, depending on how many points are achieved.
Some points are attained merely by a building’s location (in Sustainable Sites, for instance)—a brownfield site near transit and walkable to services will score highly, while a greenfield out in the country will not get points for location.
Our LEED projects in the Chicago area have all achieved Platinum, while our LEED home in rural Sangamon County “only” achieved Gold since it missed out on location points. One gripe some people have about LEED is that it doesn’t require stringent enough energy performance, but LEED is in no way restrictive. Super efficiency, net zero, and Passive design are all rewarded in the points system, so there is a great synergy between the Passive approach and the LEED rating.
2. Living Building Challenge (LBC)
LBC is the highest achievement a building can attain–a truly regenerative building. LBC asks why buildings can’t be like natural organisms, contributing to ecosystem health in all phases of their life cycle. Imagine a building as ecologically positive as a tree, which harvests its energy from the sun and soil, creates food and habitat for other species, purifies the air, and creates soil through decomposition. Unlike environmental initiatives that have merely sought to do less harm than business-as-usual, LBC challenges us to demonstrably and measurably build in harmony with each other and the natural world.
LBC uses a comprehensive system, calling its categories “Petals,” which are Place, Water, Energy, Health+Happiness, Materials, Equity, and Beauty (that’s right, Beauty is required!). Like LEED, there are prerequisites in each category that qualify a building for LBC Core certification; however, to be a fully certified living building, all petal requirements must be met.
Both Energy and Water require Net Positive performance, and performance must be proved once the building is occupied. No greenwashing here! Equity considers using local trades and material sources, and ensuring that, through the suppliers used or by donations made, the project supports equity and inclusion.
Finally, the Materials petal is a sobering one: LBC’s parent organization, ILFI, created a catalog of chemicals harmful to humans, called the Red List. No materials on a project can have Red List ingredients. The trick here is that many companies don’t disclose their product formulations, so ILFI brilliantly created a voluntary disclosure program called Declare so companies could disclose their formulations and prove that their products are clean. This call for transparency has transformed the industry by putting pressure on companies that want to be seen as environmentally sensitive: now they can prove it with an Environmental Product Declaration (the industry-standard method).
On a project, Materials Petal compliance means the design or certification team must scrutinize every single item going into the building. If no “clean” product is available, the team must write an advocacy letter to the supplier asking for improvement. This is a huge task, given how many products go into buildings nowadays.
The description “sobering” was used earlier because it highlights the stark reality of how toxic the construction industry has become, and how accustomed we’ve grown to surrounding ourselves with hazardous materials. LBC with its Materials Petal and Declare program is helping create a needed transformation.
3. Phius
This energy-focused path is the certification TBDA knows best, having designed and certified many Phius buildings. Phius was originally the acronym for the Passive House Institute US. Passive building began in the US in the 1970s in response to the energy crisis. Unfortunately, the US then stuck its collective head in the sand in the 80s and 90s (the advent of big SUVs and McMansions), but the energy efficiency movement grew up in Europe and became a certification path in Germany in the 90s, known as PassivHaus.
Once PassivHaus got its foothold here in the US, it grew and changed into Phius to best address our widely varying North American climates, US and Canadian building methods, and, importantly, alignment with the DOE’s programs, including Energy Star and ZERH. As a result, Phius is now the “top of the ladder” of US-based energy performance programs–beginning with code compliance, stepping up to Energy Star, then again to ZERH, then Phius, incorporating the requirements of all the requirements down the ladder as you climb.
The crux of Phius compliance is proving energy efficiency design through energy modeling and construction quality through third-party inspections. Since Phius is aligned with the DOE’s Energy Star and ZERH, the Indoor Air Plus and the Water Management Strategy Checklist must be met as well. These are about indoor air quality and durability, so compliance is about more than just energy.
One of the great things about Phius is that the energy metrics provide clear pass/fail requirements before any construction even starts. We use these requirements as a target on many projects, even if we are not pursuing certification, just as we use site inspection diagnostics on non-certified projects– quality control is always good!
With Phius certification, you get the highest level of quality assurance regarding the performance of the building: it’s a great investment. On top of that, because of the Phius-required ventilation system and Indoor Air Plus, you get exceptional indoor air quality alongside the famous comfort.
4. Zero Energy Ready Home
DOE’s ZERH is an energy-focused program similar to Phius, but is generally less stringent. It does require an energy model to be created and approved, and requires construction-phase inspections by a third party; it just doesn’t require quite so much of the thermal envelope or HVAC system efficiencies.
It also only requires balanced ventilation (a la Phius) in very cold climates (zones 6-8, Alaska, Wisconsin, Minnesota, Northern Michigan, etc.). That doesn’t stop Chicagoans or others from being able to install an energy recovery ventilation system, but it isn’t required here.
An Important Caveat regarding Retrofits and Remodels
Generally, certification programs can only be used if a building is getting a comprehensive retrofit. In fact we had to switch from LEED to GreenStar (a lesser known certification) on a project since the basement had been renovated prior to our design involvement on the project; LEED couldn’t be used unless the basement were part of the project, but GreenStar let us focus just on the portions we were renovating (which was everything except the basement).
Phius has a retrofit program called Revive, specifically to address how to comprehensively improve a building, even if it will be done in phases. Improvements to the thermal envelope must be sufficient to provide survivability in the face of power outages and must not exceed a moderate amount of embodied energy expenditure for the materials used to retrofit.
Value and Perception
While we can’t put a dollar value on certifications, we do hear from realtors that certification means a lot to homebuyers: instead of just taking the seller’s or builder’s word for the quality of the building, a respected institution has certified it.
Additionally, many of our clients, whether individuals or institutions, want several valuable things from certification: the third-party review that is the essence of quality control, a building or home that has superior durability, comfort, and resilience, and the ability to prove their environmental commitment to neighbors or the public!
Third-party certified buildings can be great teaching tools as well as lovable places.