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Call to Action: Voting Open Until December 6th on the Changes Proposed to the 2021 IECC

ICYMI: The code change proposals for the 2021 IECC are open for voting by Governmental Member Voting Representatives (GMVR) from Monday, November 18th through Friday, December 6th, and your vote is instrumental in making buildings consume less energy! [Need a quick refresher on the code process? Check out our blog post here!]

Does your vote even matter?

Overall, there are not actually that many voters on a given proposal. In the energy proposals, last cycle, it ranged from about 200-400 voters per proposal, even though there were a total of 1,247 voters on the Group B codes, which includes the IECC.

IECC voting numbers

So a small handful of voters can entirely shape the future of the energy codes that dictate how energy efficient our buildings will be! If history repeats itself, while some online voters tend to align with the Committee, many online voters align their votes with those cast by their fellow ICC voters at the Public Comment Hearings. This happened 81% of the time in 2016. Unlike 2016, in this cycle all the electronic votes cast during the Public Comment Hearings will be rolled into the online vote tally (although those voters can still change their vote).

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Whole Building Blower Door Testing – Big Buildings Passing the Test

The residential energy efficiency industry has been using blower door testing since the mid 1980’s to measure the air tightness of homes. Since then, we’ve evolved from testing single family homes, to testing entire apartment buildings. The Passive House standard requires whole-building testing, as will many local energy codes, along with assembly testing. While the concept of – taking a powerful fan, temporarily mounting it into the door frame of a building, and either pulling air out (depressurize) or pushing air into it (pressurize) – is the same for buildings both large and small, the execution is quite different for the latter.

Commonly called a whole-building blower door test, we use multiple blower doors to create a pressure difference on the exterior surfaces of the entire building. The amount of air moving through the fans is recorded in cubic feet per minute (CFM) along with the pressure difference from inside to out in pascals. Since the amount of air moving through the fans is equal to the amount of air moving through the gaps, cracks, and holes of the building’s enclosure, it is used to determine the buildings air tightness. Taking additional measurements at various pressure differences increases the measurement accuracy and is required in standards that govern infiltration testing. Larger buildings usually test at a higher-pressure difference and express the leakage rate as cubic feet per minute at 75 pascals or CFM75.

Image of SWA staff setting up blower door test

SWA staff at a project site setting up a blower door test

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Choosing Insulation for Carbon Value – Why More is Not Always Better Part 1

SWA’s Enclosure Group is acutely aware that insulation is the most important single material choice to maximize the enclosure’s thermal resistance over its operational life. Many of us in the building industry believe that, combined with a good continuous air seal, the highest insulation value makes the greenest enclosure, helping to reduce a structure’s carbon footprint and combat climate change. It may come as a surprise, then, that some of the most commonly used insulation materials are so carbon-heavy to manufacture and/or install, that for many decades they wipe away the carbon-energy savings they are supposed to provide.  The following is a detailed discussion of how and why this is, and what the industry is doing to change the equation.

Embodied vs. Operational Carbon

The built environment looms large in the climate picture, because almost 40% of the total carbon put into the planet’s atmosphere each year is attributed to buildings. Over the past 30 years of green building, we have overwhelmingly focused on operational carbon – the carbon that buildings emit as they are being used. Only recently have we begun to focus on embodied carbon – the carbon that goes into constructing buildings, which is typically far greater than the energy saved in the first decades of operation. Changes in energy codes are aimed at operational carbon, and even those organizations and standards that have been at the forefront of promoting sustainable building [LEED, PH] have not been quantifying or limiting embodied carbon, although they bring attention to it.

The Time Value of Carbon

Assuming that a building stands for many decades, or even centuries, its operational carbon will eclipse its embodied carbon over its lifetime, and therefore when the building’s carbon Life Cycle Assessment (LCA) is calculated, operational carbon savings will be more important than embodied carbon saved/spent in the long run. Why does embodied carbon deserve equal weight with operational carbon? Because of the total global carbon emissions from buildings, 28% is pegged to embodied carbon. That’s already a large percentage, but when you consider the near term, the first 30 years of a building’s life, the percentage jumps to about 50%. In effect, every new building is in carbon debt upon completion due to the huge amount of carbon emitted  in order to construct it., And in order for the climate to benefit from the energy savings provided by a well-insulated and sealed enclosure and a high efficiency energy system, the building needs to last and be used for a very long time. The problem is that we may not have 30 years, let alone 60, to pay off that carbon debt.

In the first 30 years of a building’s operational life, 50% of its total carbon emissions are still due to embodied carbon (Source: Architecture 2030)

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What the Climate Mobilization Act Means for Developers, Designers, and Construction Teams

Image of central park and New York City buildigns

The construction industry has been increasingly focused on meeting ever-tightening codes and achieving higher ratings in sustainability certification programs (e.g., LEED, Passive House, etc.). These standards do a good job of raising the bar, but there is a new bar in town and we’re not talking about whiskey.

Local Law 97

NYC’s Local Law 97 of 2019 establishes carbon emissions limits for buildings 25,000 square feet and larger. These emissions limits, which are based on current building performance data, will begin in 2024 and will rachet down in 2030 and beyond. While we continue to work with building owners and portfolio managers of existing buildings (“What Does the Climate Mobilization Act Mean for Building Owners?”), we need to make sure that new buildings and major renovations are set up for success. Developers, designers, and construction teams must take LL97 into account during design, construction and turnover to protect the value of these new assets.

A developer or asset manager’s least favorite word is probably uncertainty, and now there’s a whole new host of uncertainties to think about:

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Low-Carbon Concrete: Reducing the Embodied Energy of a Notorious Emitter

It is safe to say we are in a climate crisis. Of the last 17 years, 16 have been the hottest on record.[1] Sea level is expected to rise by as much as eight feet by the end of the century.[2] And by 2050, as many as 140 million people will have been displaced by climate change.[3] The time to act is now, and a major area of impact is buildings, which account for 40% of carbon emissions in the United States. Better envelopes, lighting, and mechanical systems are helping buildings become more efficient, which means an increasing proportion of carbon—up to 68% of a building’s lifetime emissions—is locked up in materials.[4] This “embodied” carbon gets released during a material’s extraction, manufacture, transport, maintenance, and, eventually, disposal.

If our industry is to meet the 2030 Challenge of carbon neutrality by the close of the decade, we will need to reevaluate building materials and select low-carbon alternatives.

Embodied carbon life-cycle

Figure 1: Courtesy of Faithful+Gould

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