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The Numbers Are In! NYC Passive House Performance Data

In a collaborative effort that merged financing and energy use analysis, the New York City Passive House industry finally has performance data. Working together with Bright Power, The Community Preservation Corporation, and NYC Department of Housing Preservation & Development, this analysis is the first of its kind.

Why does this matter?

Energy Use Intensity (EUI) measures energy consumption on a per square foot basis to compare buildings and allows interested parties to gauge one building’s usage to another (or to a group of buildings with a similar use type). The study team compared the actual EUI of six completed Passive House-certified and Passive House-like buildings against recently completed multifamily code-built buildings. Information was gleaned from the EnergyScoreCards database and the Passive House (PH) target. The weather normalized data indicates the Passive House and Passive House-like buildings are performing much better than the comparable code-built group, but are not quite as efficient as the Passive House threshold. Industry leaders have recognized this performance gap – between predictive assumptions that rely on standardized patterns of use and the real-life habits of actual people living in the building. This gap has been a hot topic  at the past several New York Passive House conferences. The results from the current analysis provide a starting point now, so the industry can focus on strategies to continue to reduce EUIs.

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Net Zero and Electrification

Net zero” can mean a lot of different things depending on what you choose to measure – zero energy usage, zero carbon emitted, zero lifecycle impact, etc.

At Steven Winter Associates, Inc. (SWA), we work with clients who are approaching net zero from different angles: driven by institutional goals, climate concerns, marketing campaigns, and connecting with municipal emissions targets. One thing we see over and over is that super high performance is difficult to achieve, but with a key simplification – there are not many ways to do it. All roads may lead to Rome but the closer you get, the fewer roads there are to take.

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Passive House: An Alternative Compliance Path to Toronto Green Standard Tier 3

It is clear to see that the Passive House (PH) standard is here to stay! Across North America, more States, Provinces, and Municipalities are integrating PH into their building standards. One of the more recent adopters is the City of Toronto. In the most recent version of the Toronto Green Standard (TGS), the PH standard is offered as an alternative compliance path to TGS Tier 3, and with this alternative compliance path one obvious question comes to mind: What is the major difference in required component efficiency for a multifamily building in Toronto that is looking to meet either the PH standard or TGS Tier 3?

The PH standard is performance-based and is focused on decreasing whole building energy demand, improving building durability, providing optimal occupant thermal comfort, improving indoor air quality, and reducing carbon emissions. The PH standard reduces building operation costs, decreases carbon emissions, and supports an improved indoor environmental quality for building occupants. The TGS has similar goals and benefits when compared to the PH standard, and there are some obvious synergies in the program design between TGS and PH. The tiered energy category in the TGS takes a similar approach to PH by offering an annual budget for three different categories. For PH you must comply with a total energy budget for annual heating demand, annual cooling demand, and total source energy use intensity. Similarly, but slightly differently, the TGS offers a budget for total site energy use intensity (TEUI), annual heating demand or Thermal Energy Demand Intensity (TEDI), and the additional category of Greenhouse Gas Intensity (GHGI). In both standards, the path to compliance is non-prescriptive and designers can implement a variety of component efficiencies and system options. See table 1 and 2 below:

 

Image of passive house criteria standards

Table 1: Passive House Standard Criteria

Second image of passive house criteria

Table 2: Toronto Green Standard Tier 3 Criteria

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The Keys to Commissioning with Kelly Westby

As code requirements become more stringent around the country, the process of commissioning is more valuable now than ever before. Acting as third-party quality assurance providers, commissioning agents help building owners by improving the quality of construction and reducing maintenance and energy costs in the long run.

On this episode, Robb interviews podcast co-host, Kelly Westby, who is also SWA’s Commissioning Director. Kelly explains the importance of quality control on any project and describes how commissioning has evolved into a process, rather than a one-off measure.

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The Making of the 2021 International Energy Conservation Code (IECC)

When I first started working at Steven Winter Associates, I didn’t know that one day I’d find myself involved in the development of codes and standards that impact how our buildings get built. I certainly don’t consider myself an expert, but I have learned a few things the hard way and thought they’d be worth sharing if you might be new to it.

So, here’s my very high-level summary of the code development process with respect to the 2021 International Energy Conservation Code (IECC), aka the “model” energy code. If you are looking for more detail, the ICC webpage has plenty of resources and a more detailed infographic than the one we’re showing and discussing here.

IECC Code Development Process Chart

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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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New York City LL92 and LL94: Sustainable Rooftops

Image of solar panelsAs part of the Climate Mobilization Act, and in accordance with the its greater carbon emissions reduction goals, New York City passed Local Laws 92 and 94 in April 2019, mandating the installation of rooftop solar photovoltaic systems and/or green roofs on buildings across the city. The new requirements will go into effect on November 15, 2019 and will apply to all new buildings and any existing buildings completing a full roof deck or assembly replacement.

The Mayor’s Office estimates that the solar and green roof installations mandated by these bills will result in 300 MW of new solar capacity, 15 million gallons of new stormwater management capacity, 1 million tons of greenhouse gas reductions, and hundreds of green jobs. Based on these projections, this will account for close to 2.5% of the city’s overall emissions reduction goals.*

The laws require that solar and/or a green roof be installed on all available roof space. Areas deemed “not available” and excluded from the requirements include:

  • Areas obstructed by rooftop structures, mechanical equipment, towers, parapets, guardrails, solar thermal systems, cisterns, etc.;
  • Fire access pathways and zoning setbacks;
  • Recreational spaces that are recorded in the Certificate of Occupancy.

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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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Become a Carbon Hero with Five Easy Tactics

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.

Integrated Design Process Image 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.

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Building Energy Performance Standards (BEPS) are Coming to D.C., Are You Ready?

In January of this year, the Clean Energy DC Omnibus Amendment Act of 2018 was signed into law, establishing minimum Building Energy Performance Standards (BEPS) for existing buildings. The law requires all private buildings over 50,000 square feet to benchmark energy use and demonstrate energy performance above a median baseline beginning January 1, 2021. If a building does not score above the median performance, it has five years to demonstrate improvement or face financial penalties.

While quite a few of the details on enforcement are still being worked out, the median scores will be based on 2019 building performance and there are actions you can take today to get ready for BEPS.

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Climate Week NYC: Seven Days of Climate Action and Discussion

 

Climate Week logoLast week, as I was writing this blog, I came across a New York Times article: “The Amazon, Siberia, Indonesia: a World of Fire.” By now, I’m sure most of us are aware that the Amazon Rainforest has been burning for weeks, but this deliberate act of environmental destruction will contribute to a feedback loop. These fires release carbon dioxide and kill the trees and species that not only remove greenhouse gasses from the air but are part of vital fragile ecosystems. As more climate-warming gasses fill the air, extreme weather patterns, drought, species loss, and global warming are exacerbated. These effects then accelerate the spread of infectious disease, global poverty, and human health defects. Overall, climate change and environmental degradation negatively affect both humans and the planet, which makes us less resilient and allows for climate change to accelerate even more aggressively. And the cycle continues.

So, for the sake of our (really wonderful) natural planet, and humankind, it is crucial that we try to hinder this feedback loop and make climate action a priority around the world. And, although individually we can try to have a more reciprocal relationship with the planet, our actions and voices carry more weight collectively, which is where Climate Week NYC comes in.

What is Climate Week NYC?

Organized by The Climate Group, Climate Week NYC is an annual week-long gathering for citizens and global leaders to join forces and take action to mitigate environmental harm caused by human activity. There will be a number of public events each day from September 23-29, including tours, film screenings, conferences, and more.

Fun fact: Swedish teenager and activist Greta Thunberg sailed across the Atlantic all the way from England to meet with UN Secretary-General Antonio Guterres, and to attend the United Nations Climate Action Summit, scheduled on the first day of Climate Week NYC!

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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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It’s Time to Focus on Our Schools

If you are a parent like me, I am sure you cherish your kids and seek to offer them the best opportunities in life. I even moved to a different school district. And, while the education is top-notch in my town, I have come to realize that it really doesn’t matter what school district you are in…all our schools need help. I am not talking about smaller class sizes, better pay for teachers, after-school programs, and more school supplies, although those are important. School buildings need attention. With budgetary pressures, a lot of maintenance and repairs are being deferred and schools are not aging well. Whether it is repairing existing systems, replacing systems at the end of their useful life, renovating, or building a brand-new school to service your community for future generations, advocate for your Board of Education (BoE) to think holistically about improving the conditions for our children.

Why My Call to Action?

This year I was asked to join our elementary school’s Tools for Schools committee, which is tasked with implementing an indoor air quality (IAQ) management plan. This experience gave me an opportunity to get involved and provided me insight into the school’s systems and the operations and maintenance (O&M) processes that were in place.

Unfortunately, at the start of the 2018 school year, mold issues were identified in our local middle school and the building was closed. In fairness, I quickly realized that buildings were outside the BoE members’ knowledge base. Afterall, they are educators, not facility managers or building scientists. They sought outside consultants but didn’t know the right questions to ask. After some time, the BoE decided to get input from local experts in the community. Fortunately, we have several experts (including me) who were willing to volunteer their time. As part of a task force, we laid out a strategy to remediate the mold issues in the school and to implement short- and long-term repairs to minimize/eliminate water incursion and elevated moisture issues within the building.

I am not saying you must get involved at this level, but I do encourage you to attend a BoE meeting and start asking questions related to IAQ. Ask if the school has deferred maintenance needs and if/when these are being addressed in the annual budget. Ask when (if) comprehensive physical needs assessments and energy audits were performed on all school buildings. Educate yourselves; then help educate your BoE and your community on IAQ guidelines for schools. Here are some great resources:

How Can SWA Help?

In working with schools, I have learned that one of the greatest challenges school decision-makers face is not knowing where to turn for support and guidance. Steven Winter Associates, Inc. (SWA) has been working to improve educational facilities for decades. Whether you have questions related to mold, moisture, comfort, absenteeism, accessibility, high utility bills…on up to zero energy design and progressive learning environments, SWA can support you. Here is just a sample of past school projects that SWA has worked on:

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Five Steps to Get Started with Net Zero Energy Buildings

Net zero buildings are becoming increasingly popular, and some jurisdictions, such as Washington, DC, are projected to become code within the decade. Massachusetts will also begin development of a net zero building code. Curious if your building is a net zero contender or what it would take to reach net zero targets?

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.

    Image of roof layout

    Typical roof layout for multifamily building, including necessary setbacks for fire access, mechanical equipment access, and shading from bulkheads. Fire access is based on FDNY guidelines.

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.

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20 Years of Wintergreen!

A lot has happened since the start of the WinterGreen newsletter, which was first distributed 20 years ago via fax machine. From the inception of LEED, to the Climate Mobilization Act, WinterGreen has covered it all.

In honor of its anniversary, we are looking back at the milestones that occurred along the way and making predictions for the future…WinterGreen Banner circa 1999

1999 – Steven Winter Becomes Chairman of the US Green Building Council

Image of Steven Winter as USGBC ChairmanAs Chairman of the U.S. Green Building Council from 1999 to 2003, Steven Winter helped guide the organization through a period of immense growth. This included the launch of Leadership in Energy and Environmental Design, also known as the LEED® Rating System, and Greenbuild, the nation’s largest green building conference and expo.

 

2000 – SWA Receives NYSERDA Pioneer Award

Image of Steven Winter with NYSERDA AwardAt a gala event celebrating the 25th anniversary of the New York State Energy Research and Development Authority (NYSERDA), Steven Winter Associates (SWA) was presented with the NYSERDA Pioneer Award for their extensive contributions to making buildings more energy efficient and sustainable.

 

2001 – Green Building Guidelines Book Published for Home Builders

Image of Green Building Guidelines bookIn conjunction with the U.S. Department of Energy (DOE), the National Renewable Energy Lab (NREL), and the Sustainable Buildings Industry Council (SBIC), SWA staff collaborated to create “Green Building Guidelines: Meeting the Demand for Low-Energy, Resource-Efficient Homes.” The book provided green building techniques and strategies for home builders and residential construction professionals.

 

2002 – SWA Helps DEC Become New York State’s First Ever LEED Certified Building

Image of New York DEC Headquarters in AlbanyWorking with NYSERDA, Picotte Companies and WCGS Architects, SWA provided certification support to the design team, earning the project LEED V2.0 Silver. SWA’s services included initial LEED tabulations and goal setting, detailed LEED V2.0 evaluation reporting, and completion of the final documentation package, which led to the certification of New York State’s first ever LEED building.

 

2003 – The Solaire Declared Nation’s First “Green” Residential High-rise

Image of The SolaireNew York Governor George Pataki dedicated The Solaire as the country’s first “green” residential high-rise building, calling it “a benchmark for urban sustainable development and for green buildings worldwide.” SWA supported the design team on this project from conceptual design phase through construction administration. The Solaire, located in New York’s Battery Park City, was the first residential building to be completed in downtown Manhattan after the terrorist attacks of September 2001, and was the first beneficiary of Governor Pataki’s green building tax credit.

 

2004 – SWA Joins Project Team for Oculus Terminal at World Trade Center

Image of World Trade Center PATH TerminalLed by the joint venture of DMJM+Harris and STV, as well as the internationally renowned architect, Santiago Calatrava, SWA was invited to join the project team to provide energy efficiency and sustainable design consulting services for the new World Trade Center station, also known as the the Oculus. The rebuilt PATH terminal is incorporated into the design.

 

2005 – USGBC Announces LEED for Homes Pilot Program

Image of home under constructionExcited to announce the first ever LEED program for residential construction, the USGBC immediately began seeking applicants to test the effectiveness of the all new LEED for Homes through a Pilot Program. LEED for Homes, which is considered a green building milestone, was made possible by a passionate committee of industry professionals co-chaired by Steven Winter.

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Rapidly Changing Brooklyn Neighborhood Welcomes Affordable and Sustainable Housing Development

image of Livonia Apartments

Courtesy of MAP Architects

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.

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The Impact of Energy Star’s Portfolio Manager August 2018 Updates on NYC’s Local Law 33 Grades

Image of Letter Grades from SmartBuildings.NYC site

Letter grades are coming!

NYC’s building owners and real estate management firms now have one more thing on their plate to consider: Local Law 33 of 2018. LL33 compliance will assign letter grades to buildings required to benchmark energy and water consumption. The energy efficiency score will relate to the Energy Star Rating earned using the U.S. EPA Energy Star Portfolio Manager (PM).

The law will come into effect on January 1, 2020, and will utilize the previous year energy data to set the energy efficiency score and letter grade as follows:

Picture of Buildings, with quote "Your energy letter grade will be posted in your lobby in 2020. Are you ready?"A – score is equal to or greater than 85;

B – score is equal to or greater than 70 but less than 85;

C – score is equal to or greater than 55 but less than 70;

D – score is less than 55;

F – for buildings that fail to submit required benchmarking information;

N – for buildings exempted from benchmarking or not covered by the Energy Star program.

Why is my letter grade lower than expected?

Property owners should be made aware that if their property earned an energy efficiency score of 75 for the 2018 Benchmarking filing, the new score for the 2019 benchmarking filing may have fallen as much as 20 points. In LL33 terms, what could have been a letter grade “B” could now be “C” or “D” based on PM updates implemented in August 2018. Property owners will want to learn how the Energy Star PM update will affect their LL33 letter grade.

To understand the correlation and impact that the August 26, 2018 Energy Star PM update will have, it is important to look back at what took place as part of that update.

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The First Certified Passive House in Southeast Asia – Star Garments Innovation Center

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 logo with project details

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?

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Is It Too Late to Start On My Local Law 87 Compliance for 2019?

Before there was a Green New Deal in New York City, there was Local Law 87, which requires an energy audit and retro-commissioning report to be conducted and filed every 10 years. Yes, it still applies, and yes it will help you to understand the most cost-effective retrofits and upgrades to target for compliance with the city’s new energy efficiency requirements. Thanks for asking!

The question we get most this time of year from owners in NYC is, “My building is due for LL87 compliance this year, is it too late to start?!”

Image of Commercial BuildingsAs spring arrives, building owners often realize that time is quickly running out and this is the year that they must submit their building. Compliance with NYC’s LL87 (Local Law 87) can be overwhelming and hard to navigate but we are here to help.

Not sure if you have to file?  Check here.

LL87 requires that a building undergo an energy audit and retro-commissioning of major mechanical equipment. Keep in mind that it takes time to perform the inspections and testing. In fact, your best bet is to start in the year before your deadline, leaving yourself plenty of time for planning, budgeting, and implementing any corrections that may be required.

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Here’s What the Clean Energy DC Act Means for Existing Buildings in the District

Mayor signing legislationDistrict 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.

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The Top 10 Party Walls Posts of 2018!

2018 has been a year to remember for SWA’s Party Walls blog. Our consultants have shared their passion for high performance buildings by recounting stories from the field and providing information, new findings, and best practices to improve the built environment.

Whether discussing topics based in New York City or Southeast Asia, here are our fan favorites from 2018…

Collage of blog images

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Looking for a Fast Payback by Installing a Dedicated Domestic Hot Water System? You May Want to Look Elsewhere

Installing a dedicated domestic hot water (DHW) plant is a common energy conservation measure (ECM) in the New York City multifamily market. According to Local Law 87 data, approximately 80% of the audited multifamily floor area uses steam heating boilers to produce domestic hot water.[1] A recent SWA analysis of data from steam buildings with tankless coils that implemented this ECM suggests that auditors may want to think twice about recommending this measure widely.

Two unsupported arguments are typically made in favor of installing a dedicated DHW system.

  1. A new condensing boiler or water heater (we will just say “water heater” here for simplicity and to distinguish the dedicated system from the heating boiler) will operate at a very high efficiency.
  2. Scotch marine steam boilers are inherently inefficient and are plagued with high standby losses. Large Scotch marine boilers fire to meet small DHW loads, and correctly sizing a new dedicated water heater will eliminate short cycling.

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Over Pressure (Part Two)

Welcome back! In Part One we talked about how steam pressure gets too much attention. Controlling pressure for its own sake should never be the end goal—steam pressure is just a means to an end. In this post we’ll discuss one way that controlling steam pressure can be useful—where it can help you balance the system, control the temperature, and yes, save energy.

Two-pipe Steam

The biggest issue plaguing two-pipe steam heating systems are steam traps. Steam traps are supposed to do just that—trap steam—keeping the pressurized steam on the supply side of the system and allowing air and water (i.e., condensate) to pass through into the returns. Keeping the supplies and returns separate is critical, but steam traps are too failure prone to accomplish this reliably.

Radiator steam “trap” failed open

Radiator steam “trap” failed open

At the start of any heating cycle, the system is full of air, which must be removed for steam to enter the heaters. In most two-pipe systems, the steam pushes the air out of the heaters, through the traps, and into the return piping where it eventually exits the system through a vent in a vacuum or condensate tank. That’s what happens when the traps are working. But a failed open trap is no trap at all. It lets the steam flow into the return piping and, with pressure on both the supply and return sides, air is trapped in the system. This affects those farthest from the boiler—the heaters near the ends of the mains and on the top floors—the most.  (And with air trapped inside keeping the metal cold, are they even heaters?)

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Just Your Typical Blower Door Test… in Sri Lanka – Star Garment Innovation Center

As the number of projects pursuing Passive House certification increases, so does the demand for whole building blower door tests. And so, performance of recent blower door tests took us to uncharted territory, not only for SWA, but for the Passive House Standard.

Rendering of Star Garment Facility

 

Working remotely with a project team across the globe, the Passive House team at SWA was tasked with retrofitting an outdated factory in Katunayake, Sri Lanka, into a Passive House certified garment manufacturing facility. Jordan Parnass Digital Architecture (JPDA) recruited SWA to provide technical assistance to the project team. Responsibilities for this project included Passive House design analysis and recommendations, mechanical design review, energy and thermal bridging modeling, and the testing and verification necessary to achieve certification from the Passive House Institute (PHI).

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Foundation Waterproofing – Proper Installation and What NOT to do!

As mentioned in Foundation Waterproofing 101, water damage to a foundation can be very costly and difficult to repair. By paying close attention to how and where water might enter the foundation during the early stages of construction, typical failures can be avoided by following these simple guidelines…

For the Designer: Keys to proper installation

Design and Quality Assurance

  • Don’t wait to design the foundation waterproofing system after you’re already in the ground!
  • Specify and detail the appropriate system for each project. Meet with manufacturer reps early!
  • Require shop drawings and kickoff meetings to ensure the entire team understands the importance of the design! Review examples of common failures.
  • Get your consultants on board early: Geotechnical engineer, Structural engineer, Waterproofing/enclosure consultant.
  • Review warranties, require third party inspections, installer certification, and contractor training.

For the Installer: Keys to proper installation

Substrate preparation

  • Provide smooth continuous surfaces to install waterproofing – minimize jogs, protrusions, and sharp edges.
  • At slabs: compacted fill/rigid insulation board/rat slabs
  • At walls: fill bugholes, remove/grind concrete fins, mortar snots, fill form tie holes, verify form release agents and compatibility.

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Trying to Be Rational in an Irrational World

Think about the last time you went looking for a new car. What did you look for? I am guessing you started with your needs for a vehicle. Are you looking for a large car/SUV to move a lot of people or equipment, a car for commuting to work, or something to enjoy on the weekends? Next you probably were interested in the looks of the vehicle because it is a large investment and you should like what you drive. I am guessing you glanced at the miles per gallon (mpg) of the car. You even likely went online to see reviews from others on the comfort, crash test rating, and typical maintenance issues of the car. Of course, you will need to look at the sticker price. I am even assuming you asked to test drive the vehicle to make sure that the information that you obtained aligns with how you perceive the vehicle.

Image of animated home Now, what if I told you that you must make that vehicle purchase decision only based on the dimensions of the car, the features (radio, A/C, seat controls, etc.) of the car, some pictures of the interior, and the price. Do you think you could decide on which car you would want? My guess is that you would say I am crazy and that you wouldn’t make the decision on such a pricey purchase with so little information. But, that is exactly what millions of people do when making a significantly more expensive purchase… a home.

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Multifamily Passive House Ventilation Design Part 2: HRV or ERV?

*click here to read Part 1 of this blog

In climates with significant heating and/or cooling seasons, Passive House projects must have a balanced heat or energy recovery ventilation system. These systems use a heat exchanger to transfer heat and moisture between the outgoing return and incoming outdoor airstreams. The operation of recovery ventilators reduces the energy required to heat and cool decreasing the building’s carbon footprint. Project teams can select either:

  • Heat Recovery Ventilators (HRV) that transfer heat from the return air stream to the outside air stream; or,
  • Energy Recovery Ventilators (ERV) that transfer heat and moisture from the return air stream to the outside air stream.

Deciding between an HRV and an ERV gets more complex when the Passive House concept is scaled from a single-family home to a multifamily program. What the industry has learned from the development of airtight buildings and programs such as Passive House and R2000, is that indoor relative humidity must be controlled through continuous ventilation. The extremely air tight building envelope required of a Passive House, combined with high internal moisture gains from an occupant dense multifamily program (coming from occupants, kitchens and bathrooms), forces additional moisture management considerations during mechanical ventilation design. Maintaining acceptable interior relative humidity in both the heating and cooling season is paramount for building durability and occupant comfort. It’s appropriate that Passive House professionals claim this simple motto: “Build tight, ventilate right!”

In New York City where the multifamily Passive House market is rapidly growing, there is a significant heating season and a demanding cooling season with high humidity (Climate Zone 4A). With this seasonal variation, there are four primary operating scenarios for an HRV or ERV that need to be considered during design:

Summer Condition – HRV

An HRV operating in the summer (hot-humid exterior air and cool-dry interior air) introduces additional moisture to the building through ventilation. Heat is transferred from the incoming outside airstream to the return airstream leaving the building which cools supply air, but exterior moisture is not removed from the incoming air. The building’s dehumidification load increases as a consequence of additional moisture from the outdoor air.*CON*

HRV Summer operation (more…)

Multifamily Passive House Ventilation Design Part 1: Unitized or Centralized HRV/ERV?

*click here to read Part 2 of this blog

Project teams pursuing Passive House frequently ask, “Where do we locate the HRV/ERV?” The answer is complex when the Passive House concept is scaled to a multifamily program.  While there are two primary arrangements for HRV/ERV systems, the trade-off is dynamic and needs to be carefully considered as multifamily Passive House projects begin to scale. A low volume HRV/ERV unit ventilating an individual apartment is a unitized HRV/ERV. High volume HRV/ERV units ventilating multiple apartments and often servicing several floors, is referred to as centralized HRV/ERV.

As Passive House consultants we can attempt to address the system arrangement question with building science; however, in New York City rentable floor space is very valuable, so considering the floor area trade-off is of particular interest to project teams. When a unitized HRV/ERV system cannot be located in a drop-ceiling due to low floor-to-floor height, it is placed in a dedicated mechanical closet. This closet is typically no smaller than 10 ft2 and includes the necessary ductwork connections to the HRV/ERV unit. The alternative solution is to increase the floor-to-floor height to accommodate the HRV/ERV unit and horizontal duct runs in the ceiling. Centralized HRV/ERV systems, however, allow short horizontal duct runs but require floor space to accommodate vertical shafts. With supply and exhaust ducts coupled together the required floor area is about 8-12 ft2. As a result, centralized HRV/ERV systems may actually require more floor area than a unitized system.

Example: In the case of Cornell Tech, vertical supply and exhaust duct work for the centralized HRV/ERV system required 222.5 ft2 per floor, or 13 ft2 per apartment (see image 1 below). Unitized HRV/ERV mechanical closets would have required an estimated 170 ft2 per floor, or 10 ft2 per unit (image 2 on right).

Comparison images HRV/ERV

Image 1 & 2:  These images compare the amount of floor area required for centralized and unitized HRV/ERV systems. Image 1 on the left, shows the 12ft2 floor area required for vertical shafts servicing the centralized ERV at Cornell Tech. Image 2 on the right is hypothetical, showing the typical location and 10ft2 floor area required for a unitized HRV/ERV mechanical closet.

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Recovering from Heat Recovery Woes

IECC Image

The International Energy Conservation Code (IECC) has a number of requirements involving energy recovery on ventilation systems. Requirements vary based on climate zone, building type and size, equipment capacity, and equipment operating hours. As a result, many new construction projects must now incorporate energy recovery considerations into their design.

An energy recovery unit (ERU) equipped with a heat wheel can be a great way to satisfy these energy recovery requirements. The ERU can be a roof-mounted air handling unit, or can be an air handling unit located inside a mechanical room with outdoor air and exhaust streams ducted in. The heat wheel is positioned so that half of the wheel sits in the exhaust air duct and the other half sits in the outdoor air intake duct. During cold weather, the wheel spins, transferring heat from the exhaust stream to the outdoor air intake stream. During hot weather, the wheel transfers heat from the outdoor air intake stream to the exhaust stream. In both cases the heat exchange enables the building to take advantage of the more comfortable conditions of the exhaust air, while still allowing fresh air to enter the building. During extreme weather conditions, heat wheels can save energy on space conditioning while still allowing for healthy indoor air quality.

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When the Rubber Meets the Road

 

As the Passive House standard continues to make waves across New York City and the U.S., an entirely new design process has evolved to respond to the challenges of higher insulation levels, balanced mechanical ventilation, and perhaps the most difficult hurdle – an air tightness level that most would think is impossible. For the recently certified Cornell Tech building on Roosevelt Island, the tallest Passive House in the world, a several year-long coordinated effort was required to achieve such a feat. So what is the requirement, how is it measured, and what are the strategies and considerations required to achieve it?

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Transformers: Problems in Disguise

Sometimes a significant source of energy inefficiency in a building can be hiding in a place difficult to detect. In some buildings, a single transformer can have a substantial impact on electrical consumption.

Image of currents flowing through a transformer

click to enlarge

Some Background

Transformers are responsible for stepping the incoming voltage to a building up or down depending on the design, intended use, or connected equipment.  A standard electrical socket in a US home or office will deliver 110-120 volts AC. Some appliances require 240 V instead. Large mechanical equipment, such as the air handling units, distribution pumps and chillers found in commercial or multifamily buildings may require 460 V. In buildings where the incoming voltage from the utility does not match the voltage required by connected equipment, a transformer is used to deliver the necessary voltage.  The voltage entering the transformer is called the primary voltage and the voltage delivered by the transformer to the facility’s equipment is called the secondary voltage.

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What We’re Looking Forward to at Building Energy Boston ’15

Building Energy BostonBoston has been making national headlines a lot this winter, mainly due to the #snowpocalypse that they’ve been enduring.

Never fear, the first sign of spring is about to appear in Beantown! NESEA’s Building Energy Conference is just around the corner on March 3-5, bringing experts from around the country to share their knowledge about new trends and innovative solutions within the realm of building science and renewable energy.

Road? Where we're going, we don't need roads.

Boston digs out in time for Building Energy 2015

We’re sure it will rejuvenate and reinvigorate Bostonians and all Northeasterners alike. Note: Northeasterners like the people, not northeasters like the storm, just to be clear.

As with most of the Building Energy Conferences, there will be many speakers from SWA there to lead workshops and sessions about improving the efficiency of buildings and their systems (You can read more about that here). Today though, we want to talk about the other presenters and topics that we’re excited to see!

Here are a few of our recommendations that we can’t wait to check out:

  • We have been preaching about addressing building resiliency and energy efficiency, want to hear it from another trusted voice? Attend Alex Wilson’s session Putting Attention Where it is Needed Most – Building Resiliency In Multifamily Affordable Housing.  March 4, 11am – 12:30 pm
  • Codes are raising the bar, owners are seeing the benefits of building more efficient housing and more owners are addressing energy use at the time of capital upgrades and refi, all great news. The next wave we will see is the increase in multifamily Passive House construction and renovation using techniques where possible. Want to know how to incorporate passive house to your next project, you can talk to SWA’s Lois Arena, and you can also hear it from Katrin Klingenberg at her session The Building Science of multifamily Passive House. March 4, 4pm – 5:30 pm
  • Water makes up a sizable portion of utility bills, we recommend attending Reinventing the Water Grid Part 1: Science, Behavior and Dollars. Water reduction strategies and monitoring can save money and reduce operations and maintenance costs through leak detection. We will be attending this session to reinforce what we are recommending and to see if there are new applicable techniques or recommendations we can incorporate into our projects. March 5, 10:30am – 12pm

To attend Building Energy 2015 in Boston, register here. We look forward to seeing everyone there!