Party Walls

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.

(more…)

Before you can really dig deep into the advanced design concepts of embodied carbon analysis and whole building energy modeling, you must first perform some bare minimum prep work. An easy way to get the pre-schematic plan up on its legs quickly is to add qualitative performance measures to the architect’s program study or create an Owners Project Requirements (OPR) document. For this article, “qualitative performance measures” refer to the metrics that express embodied carbon, but can also include operational energy, water, and even healthy materials.

An integrated design process (IDP) anchors the architectural program to performance metrics such as carbon dioxide equivalents (CO²e), Energy Use Intensity (EUI), and zero Energy Performance Index (zEPI). So, by completing the IDP, you’re getting the basic tools to optimize embodied carbon and operational energy use in your design:

1. Target the early phase of the project
2. Prepare a Carbon Hotspot and Simple Box energy analysis to compare carbon sensitivity of different schemes not limited to wall and roof construction, massing, and solar exposure.
3. Schedule a workshop with the design team and owner to discuss findings and recommendations.
4. Establish performance targets such as total Carbon Dioxide equivalents as a basic program requirement.
5. Choose a compliance pathway and verify design with Life Cycle Analysis and a Whole Building Energy model.

(more…)

 

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:

(more…)

Heat Pump Water Heaters in Multifamily Buildings

In Electrify Everything? Part 1 that I wrote several months ago, I mentioned that integrated tank heat pump water heaters (HPWHs) can work well in single family homes — even in colder climates. For example, we see quite a few installed successfully in basements in the Northeast. These devices remove heat from the surrounding air, so there needs to be enough heat in the basement air for them to work effectively. During the winter, a home’s space heating system probably needs to work harder to make up for the HPWH. In the summer, the HPWH provides a bit of extra cooling and dehumidification. We put together some guidelines a few years ago on how to get the most from these systems in single family homes.

Some places where I’ve seen problems:

•   Installing a HPWH in a basement closet. Even if a closet has louvered doors, there’s not enough heat/air for a HPWH to work well.
• HPWHs are relatively loud. If there’s a finished part of the basement (e.g., bedroom or office), the noise can be disruptive.
• Sometimes there is trivial heat gain to the basement (from outdoors, mechanical equipment, etc.). When a HPWH removes heat from the air, such a basement can quickly become too cold for the water heater to work efficiently (and too cold for comfort if someone uses the basement).

But overall, HPWHs in single family basements can work effectively.

(more…)

Net zero buildings are becoming increasingly mainstream, with many jurisdictions adopting policies to move towards net zero new construction codes. A good overview of advanced energy codes is available on the Getting to Zero Forum, which includes a snapshot of activity around the country including Washington, DC, New York and Massachusetts.

What Does it Mean to be Net Zero?

The term “net zero” commonly refers to zero-energy buildings. In simple terms, a zero-energy building is one that produces as much energy as it consumes on an annual basis. There can be nuances and caveats to this definition, but for now, we want to bring you up to speed on five key net zero energy strategies to consider if you’re interested in developing a net zero building.

1. Maximize space for on-site renewable energy.

How tall is your building?

• Any building over five stories will be challenging, if not impossible, to achieve net zero with on-site renewable energy production alone because building energy demand will likely exceed available site area. Maximize your solar with a smart layout and consider if other renewables, such as geothermal, are possible.

Do you have other spaces available for solar photovoltaics (PV)?

• Your development may have a separate parking garage or parking lot on site. These are great places to install a PV system, which can significantly increase the amount of on-site renewable energy production and help make achieving net zero more of a reality.

Do I have to have all renewables on-site to be net zero?

• If you don’t have enough room for on-site renewables, you can look into purchasing off-site renewable energy options, such as community solar, power purchase agreements, or renewable energy credits.

Now that you’ve considered renewables, let’s move on to net zero building design considerations.

(more…)

The Livonia Apartments is Phase II of an affordable sustainable housing development in the rapidly changing neighborhood of East New York, Brooklyn. Through a partnership with the NYC Department of Housing Preservation and Development (HPD) and the New York City Housing Development Corporation (HDC) and designed by Magnusson Architecture and Planning (MAP), BRP Companies and partners developed this mixed-use, four-building complex to provide 292 apartments of both affordable and supportive housing, including 10% of units specified for persons with disabilities and municipal employees. In addition, Livonia II provides 30,000 square feet of community and retail space for the neighborhood.

The size and density of The Livonia Apartments project represented an opportunity to set a higher benchmark in green design strategies. Mayor Bill di Blasio stated at the groundbreaking, “For decades these vacant lots have been a blight on this neighborhood. Today, we’re breaking ground on a project that will deliver the affordable housing, good local jobs and vital services this community needs. We believe in a city where every neighborhood rises together, and where we make investments that give more people a shot at a better life.” Although the development straddles the busy elevated L & 3 trains and the Livonia Ave. station, the buildings’ facades are angled to minimize the sound and rattle from the trains, while maximizing privacy and natural light.

(more…)

Following up on our blog post in August 2018 – Just Your Typical Blower Door Test… in Sri Lanka – Star Garment Innovation Center – we have exciting news coming out of Sri Lanka. The Star Garments Innovation Center is now officially certified as a Pilot EnerPHit building, the building retrofit standard under the Passive House Institute (PHI).

EnerPHit certification for this project is a milestone achievement on many levels. The Innovation Center is now the first certified Passive House in Southeast Asia and one of only a handful of certified PH projects in tropical climates. PHI deemed the project “a milestone in industrial energy efficient retrofitting in a tropical monsoon climate.” Many of the passive measures employed at the Innovation Center, including continuous exterior insulation, highly efficienct windows, variable refrigerant flow heat pumps for cooling with wrap around heat pipe for enhanced dehumidification capacity, and balanced ventilation with heat recovery can be utilized across all future construction projects in tropical climates. The Passive House team here at SWA is excited to see the potential growth in tropical-climate Passive House construction as a result of the Innovation Center’s success.

But what good is certification if the building doesn’t perform as well as the energy model predicts? Well, we have exciting news on this front too!

At the very start of SWA’s involvement in the project back in the summer of 2016, SWA conducted a utility analysis of the base building prior to any renovations to predict and later verify the energy savings of the Innovation Center by designing to the PH standard. Once the energy model was developed, SWA predicted approximately 50% in energy savings when compared to the previous building’s energy bills.

Fast forward to Fall of 2018 and the building has now been occupied for a full year. The two inevitable questions are:

1. How much energy is the Innovation Center saving as compared to the previous building?
2. How does the modeled energy use for the Innovation Center compare to what it is actually using after a full year of occupancy?

(more…)

On April 18th, Introduction 1253-2018 was approved by the New York City Council along with several other major pieces of legislation as part of a Climate Mobilization Act. The Urban Green Council describes it as “arguably the most disruptive in our lifetime of the NYC real estate industry.” We agree. While it will take some time to more precisely gauge impact across the industry, here is an initial primer.

Update: On May 18^th Intro 1253 was passed into law as Local Law 97 of 2019.

Context

Previous building energy legislation in NYC has focused primarily on providing the market with access to information in the form of benchmarking and audits. In response to increasing demands for more urgent climate action, this new local law will actually require energy performance levels – and significant retrofits in some cases – in most existing buildings over 25,000 square feet between now and 2030 and deeper reductions beyond 2030.

How Does Local Law 97 Work?

The law establishes targets for carbon-emissions intensity per square foot for buildings based on occupancy class. For instance, multifamily buildings, office buildings, schools, and storage facilities will have different intensity targets. Mixed-use buildings will have their targets set based on a weighted average of their different spaces. Across all segments, these targets will get ratcheted down over time. Building on the type of data submitted as part of annual benchmarking, all tenant and owner energy used at a particular building will be converted to carbon intensity per square foot.

Starting in 2024, buildings will be fined on an annual basis for carbon footprint that exceeds their targets. Based on their performance today, approximately 20% of buildings exceed the 2024 – 2029 targets while approximately 75% of buildings exceed the 2030 – 2034 targets, according to the City Council’s press release. As an alternative to this performance-based framework, rent regulated multifamily buildings with at least one rent stabilized apartment will be required to implement a prescriptive list of upgrades by 2024. These upgrades include indoor temperature sensors providing feedback to boilers and apartment thermostatic controls.

What Will It Mean to the Market?

(more…)

The Intergovernmental Panel on Climate Change (IPCC), viewed as the most credible source of climate change research, issued an alarming report on October 2018 removing all doubt – absent aggressive action the atmosphere will warm up by as much as 2.7 ° F above preindustrial levels by 2040, inundating coastlines and intensifying droughts and poverty. The significance of this report is that the effects of climate change will occur in our lifetime.

The building construction sector has a critical role in drawing down carbon emissions by 2040. As nations all over the globe tackle operational emissions from buildings, we must now address our total emissions impact.

 

Life-cycle emissions resulting from buildings consist of two components: operational and embodied. A great deal of effort has been put into reducing the former as it is assumed to be higher than the latter. Studies have revealed the growing significance of embodied emissions in buildings, but its importance is often underestimated in energy efficiency decisions.

According to the Embodied Carbon Review 2018 by Bionova Inc, embodied carbon is the total impact of all the greenhouse gases emitted by the construction and materials of our built environment. Furthermore, during their life-cycle, the same products also cause carbon impacts when maintained, repaired, or disposed of.

(more…)

District of Columbia Mayor, Muriel Bowser, signed a landmark piece of legislation known as the Clean Energy DC Omnibus Amendment Act this past Friday. With the mayor’s signing, Washington, DC becomes one of the first jurisdictions in the country with a binding, comprehensive law aimed at reducing greenhouse gas emissions. “It allows us to make significant improvements to the energy efficiency of existing buildings in the District,” Mayor Bowser said at the signing ceremony.

The new law has several sections which will impact the buildings in which DC residents and businesses live and work. In this post, we’re going to focus on Title III of the Clean Energy Omnibus Amendment Act, which is designed to make the city’s existing buildings more efficient.

(more…)