Concentration of CO2 in the Atmosphere

Health, Wellness, and High-Performance Building.

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Health, Wellness, and High-Performance Building.

 

 

Karla Butterfield, Sustainability Director, Steven Winter Associates, Inc.

Making a Business Case

Today’s homeowner knows more about carbon reduction, energy efficiency, and good indoor air quality than ever before. The New Home Trends Institute by John Burns Real Estate Consulting, LLC surveyed 1,263 homeowners and single-family renters age 18+ with household income of $50,000+ and published some interesting findings. The general lesson is a trend where health and well-being is valued and an acknowledgement that the home building industry has a responsibility to its customers and the environment.

Homebuilding impact graph is shown here.

Half of those surveyed believe the industry has a somewhat, or very negative impact on the environment. Changing that perception will take creating high-performing, healthy buildings, while lowering carbon emissions.

How to Make it Happen

In most cases, the building code sets the bar for builders. And while we may think advancements have been slow, the 2021 International Energy Conservation Code (IECC) made significant progress with reducing carbon emissions. A Pacific Northwest Laboratory (PNNL) study determined that the 2021 IECC represents 9.4% site energy savings improvement and 8.7% carbon emission reductions for residential buildings relative to the 2018 IECC. The problem is that states can be slow to adopt progressive codes. Or, like the 2022 Connecticut State Building Code, the 2021 IECC was adopted but then amended to be less rigorous. However, all that may be changing due to the State and Community Energy Program (SCEP) funding from the Inflation Reduction Act (IRA) where states will receive grants for implementing the 2021 IECC or other codes with equivalent or greater energy savings. Some states are already there. Massachusetts, for instance, adopted an unamended 2021 IECC as the baseline, and a more rigorous Stretch code is mandatory if designated as a Green Community under the Green Communities Act. Taking an even bigger step, Massachusetts communities opting into the specialized code require Passive House or equivalent for all new construction.

Air sealing guide image is shown here.+

Beyond energy savings, what’s in the 2021 IECC that addresses health and wellness? For one thing, air infiltration testing is a requirement, regardless of building size or type. Mechanical ventilation is also required. This means fresh air coming into and leaving our buildings is quantified and controlled.

Building Best Practices

Two heat pump photos are associated with this paragraph

Design and build professionals who previously embraced volunteer programs such as ENERGY STAR, LEED, NGBS, and Passive House find themselves ahead of the code curve. But how does the rest of the industry get there? Step 1) Install a continuous air barrier that aligns with the thermal barrier (insulation). And pay attention to air sealing, including compartmentalization in multifamily buildings (i.e., unit to unit, unit to corridor, etc.). Engage the energy rater early and perform preliminary testing to inform where air sealing needs to improve before things are closed-up. Step 2) After choosing high-efficiency heating and cooling (HAC) equipment, focus on the delivery system. If ducted, keep the runs simple, short, and fully duct the return side to the air hander. Squeezing a heat pump into a ceiling cavity almost always leads to construction sequencing issues and poor installation. For example, the return duct to the heat pump shown in the graphic was designed to be fully ducted. Return air should pass through the return grill and filter then directly to the equipment. Unfortunately, that didn’t happen here. Drywall was completed before the mechanical rough-in was done so by the time the installer tried to finish the sheet metal return, the space was too tight. Instead of a nice clean return duct, the air path is through a cavity full of dust and debris. Installing non-ducted HAC systems is one way to avoid these issues. However, some options, such as mini-splits lack good filtration. 10% of consumers from the New Home Trends Institute survey were familiar with the term “MERV” (Minimum Efficiency Reporting Value). As industry professionals, we’ve been screaming “MERV 13” for years. Which seemed to fall on deaf ears until we found ourselves in a post-COVID world. Now homeowners are savvy enough to ask for efficient, healthful homes with good MERV filters!

Sustainability-linked Loans

Homeowners and renters aren’t the only ones asking for lower carbon buildings. Sustainability-linked loans are the fastest-growing component of Environmental Social Governance (ESG) debt. Bloomberg Financial tracked a five time increase in ESG loans from 2020 to 2021 a steadily increasing pace for 2022. To meet ESG reporting requirements, investors are asking for third-party certified buildings. And it’s not just European investors, both Fannie Mae and Freddie Mac have “green” loan programs. Again, the design and build professionals who embraced these volunteer programs early-on, find themselves ahead of the curve. But how can any project team take advantage of these programs and satisfy ESG objectives? Step 1) pursue a third-party certification or labeling program and Step 2) pay attention to both operational and embodied carbon emissions. When a building is in use, it produces Green House Gas (GHG) emissions. The more efficient the building, the less energy it uses, the fewer operational emissions it produces. Embodied carbon emissions come for the stage before and after the building is in use. These emissions are from the extraction, transportation, and manufacturing of the materials that go into the building. As well as the end of its useful life, where demolition and waste are accounted for. While there are many modeling tools that will predict the embodied carbon in our choices, we can also choose to limit or avoid the “heavy hitters” such as, concrete, aluminum and steel, poly-based insulation, glass, and hydrofluoro-based refrigerants.

Marketing, Use, Post-sale

The New Home Trends Institute survey also concluded that while most homeowners and renters want more efficient, healthier homes, they want a three-year rate of return! Opportunities to reduce costs can include utility rebates, state incentives, and the IRA 45L tax credits ($5,000 for achieving Zero Energy Ready Homes). Once the home or building is complete, there are a few more steps to help ensure the systems are working as designed and the homeowner (or occupant) is comfortable: 1) register all equipment with the manufacturer to secure and extend manufacturer warranties, 2) provide the homeowner an educational session, 3) provide a “one box” service to annually deliver every filter the home needs and, 4) visit the home twice a year to inspect and service things. As design and build professionals, we know the steps to create the sustainable, efficient, healthful homes the consumer is demanding.

Karla Butterfield is Sustainability Director of Steven Winter Associates, Inc.

Captions

  1. Graph: Source: Consumer Insight Data

  2. Image for SWA’s air sealing guide

  3. Squeezing a heat pump into a ceiling cavity almost always leads to construction sequencing issues and poor installation. (Courtesy photo)

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