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Pathways to Passive House Certification

Passive House logosDid you know that there are two pathways for earning Passive House certification? There’s Passive House International (PHI) and Passive House Institute US (PHIUS). Using an energy modeling software, both programs evaluate a building based on a variety of factors. Despite the misleading moniker, certification is not limited to just housing. In fact, building types from residential and commercial high-rises to industrial factories have earned Passive House certification around the globe. However, the two certification programs are run by separate institutions, using different energy modeling software and standards. However, both ultimately maintain the shared goal for high performance, low energy buildings.

Historically, around 2013, the PHIUS organization developed a new standard called PHIUS+ 2015 with a climate-specific approach and an alternate modeling software. Starting in March 2019, PHIUS projects will be held to updated requirements under the PHIUS+ 2018 program.

PHI also offers project and climate specific cooling demand thresholds, having previously begun offering alternate certification options in 2015. Additionally, PHI created a program called EnerPHit to provide more flexibility for retrofits. PHI recognizes buildings that exceed its standard certification by offering Plus and Premium certification, as well as a Low Energy Building certification pathway for projects that are near PH efficiency.

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Bridgeport, CT – A Model for Resiliency

The pattern along the water’s edge in Bridgeport, Connecticut presents a familiar scene to New Englanders: active harbors and historic homes interspersed with blighted buildings and weathered infrastructure. The city’s architecture suggests a prosperous past and a difficult present. But this city—prone to acute and chronic flooding, and facing the ills of climate change and sea level rise—will not leave its future to chance. The City of Bridgeport has a plan to survive and even thrive in the next decades of environmental change, and may position itself as a national leader in resiliency.

Map of the study area showing proposed floor barriers and low impact development

Map of the study area showing proposed flood barriers and low impact development

In this context, “resiliency” refers to adaptation to the wide range of regional and localized impacts that are expected with a warming planet. Last fall, David Kooris, former Connecticut Director of Housing, visited SWA’s Norwalk office and presented Bridgeport’s vision: Resilient Bridgeport. The project began in 2014 when the City assembled a multidisciplinary design team, led by New Orleans-based Waggonner and Ball, to prepare an integrated resilience framework for the U.S. Department of Housing and Urban Development’s (HUD) Rebuild by Design Competition. The following year, Connecticut was awarded a HUD grant of $10,000,000 to develop a plan for reducing flood risk, improving resilience for the South End and Black Rock Harbor areas, and building an ambitious pilot project in the South End that combines physical barriers and low impact development.

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LEED v4.1 O+M is All-In!

Are you in? The US Green Building Council (USGBC) wants you to be. The “All-in” campaign has just officially expanded to include the new and highly anticipated LEED v4.1 for Building Operations and Maintenance (O+M).

Full disclosure: As a member of the Energy and Atmosphere (EA) Technical Advisory Group, I was involved in reviewing LEED v4.1 modifications. In the past, LEED had set significant barriers to entry for existing buildings. For example, LEED O+M EA Prerequisite Minimum Energy Performance set a baseline ENERGY STAR score of 75, which restricted certification to the top 25% of efficient buildings. This limitation often caused building owners to abandon LEED before even getting started, thus eliminating a key incentive for improving underperforming buildings’ environmental impact. LEED 4.1 has fixed this problem. The restrictive prerequisite for energy performance has been replaced with a voluntary credit, encouraging building owners to benchmark energy use and screen capital improvements against energy impacts.

The newest version of LEED O+M also incorporates Arc, USGBC’s performance tracking platform. In Version 4.1, the energy score is calculated based on two energy metrics:

  1. LEED v4 ImageThe traditional ENERGY STAR metric of annual Source Energy Use Intensity (kBtu/sf);
  2. The Arc metric of Annual Greenhouse Gas Emissions Intensity (GHG/person).

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Tech Notes: Accessible Design Solutions for Protruding Objects

Limits of Protruding Objects
[US Access Board]

When most people think about accessible design, the first thing that comes to mind is designing for people in wheelchairs. However, there’s a lot more to it than that. Requirements in federal, state, and local accessibility laws and codes account for a wide range of disabilities, including vision impairments. One of the most important design considerations for people with vision impairments is eliminating projections into the circulation path. Objects projecting from walls or other fixed elements can pose a hazard if they do not meet certain requirements. Any object that extends more than 4 inches into the circulation path between 27 and 80 inches above the finished floor is considered a protruding object and must be protected by a fixed cane detectable barrier installed below the object.

There are many ways to provide adequate protection at protruding objects and our accessibility consultants are always keeping an eye out for accessible design solutions that look like they were an intentional part of the design, rather than an afterthought. Here are just a few of the more successful and aesthetically pleasing examples of cane detectable barriers that we have come across…

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The Second Leading Cause of Lung Cancer May Not be What You Expect

National Public Health Week is this week and Today’s theme is “Environmental Health”, which includes protecting and maintaining a healthy indoor environment.

While National Radon Action Month was in January, we wanted to share how this specific indoor air pollutant can affect your health and what compelled a group of us here at SWA to get our homes tested (and remediated).

What is radon and why does it matter?

Map of EPA Radon Zones

EPA Map of Radon Zones

Radon gas is a naturally occurring byproduct of the radioactive decay of uranium found in some rock and soil. You can’t see, smell or taste radon, but it may be found in drinking water and indoor air. This carcinogenic gas is currently the second leading cause of lung cancer after smoking, according to the National Cancer Institute.

Although radon in drinking water is a concern, radon in soil under homes is the biggest source of radon, and presents the greatest risk to occupants. This pressure-driven mechanism occurs when radon escaping the soil encounters a negative pressure in the home relative to the soil. This pressure differential is caused by exhaust fans in kitchens, bathrooms and appliances, as well as rising warm air created by furnaces, ovens and stoves.

Radon levels can vary dramatically within a region, county, or city. However, the EPA recommends that all homes be tested, regardless of geographic location. To see what the average levels are in your area, check the EPA Radon Zones map.

What radon levels are accepted? Ideal?

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ENERGY STAR New Construction Certification Programs for Multifamily to be Combined

ENERGY STAR MF LogoCurrently, to receive ENERGY STAR® certification for multifamily new construction, you would get your certification through the ENERGY STAR Certified Homes program or the ENERGY STAR Multifamily High Rise program. This may change by early 2020. According to the Environmental Protection Agency (EPA) in a recent statement, multifamily will soon have a single program, rather than splitting them across the Certified Homes program and the Multifamily High Rise program.

“To better serve the multifamily sector, EPA is in the process of creating a single ENERGY STAR multifamily program by merging the current requirements and adopting the most appropriate from each.”

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Can you do a HERS Rating on an apartment in a 30-story building? Not now, but maybe in 2019!

ANSI/RESNET/ICC 301-2014 is the Standard for the Calculation and Labeling of the Energy Performance of Low-Rise Residential Buildings using an Energy Rating Index. It is the basis of the most common Energy Rating Index, RESNET’s HERS Index, which is utilized by utilities and building programs like LEED© and ENERGY STAR®, which require a consistent index to evaluate performance.

ANSI RESNET ICC 301-2014 imageOn March 2, 2018, RESNET released a draft of the 2019 version of ANSI/RESNET/ICC 301, where the most significant change will be the expansion of its scope to include Dwelling Units and Sleeping Units in ANY height building, whether that building is defined by IECC as “Residential” or “Commercial”. Other changes will include those developed by the RESNET Multifamily Sub-Committee, to better address shared systems like HVAC, hot water, solar PV, and laundry, and other scenarios specific to multifamily buildings that have largely been unaddressed until now.  The 1st preliminary draft standard of the 2019 version (dubbed PDS-01) includes these important improvements, along with all addenda to Standard ANSI/RESNET/ICC 301-2014 that were approved prior to March 2.

How Does the Revision Process Work?

The ANSI/RESNET/ICC Standards 301 (and 380) are under “continuous maintenance”. What does this mean? As revisions are needed to improve the standards, they are accomplished via “addenda”. Each addenda has to go through a “public comment” period to ensure that all stakeholders get to provide their opinions or objections to the proposed change before it becomes part of the standard. Rather than re-publishing a new edition of the standard each time a revision is approved, these standards are instead updated every 3 to 5 years to integrate any approved addenda into the body of the standard (instead of as separate addenda), along with any other necessary revisions into a new edition. This is similar to other standards like IECC, ASHRAE 62.2, or ASHRAE 90.1, which typically release a new version every 3 years. (more…)

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*

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The Energy Code of the Future: Modeling and Performance-Based?

It has been clear for some time that energy codes are on course to require carbon-free buildings by 2030. Adoption at the local level will see some areas of the country getting there even sooner. For example, California has set net zero goals for its residential code by 2020. These developments have accelerated the debate about the effectiveness of energy modeling versus performance-based approaches to compliance.

Chart: Improvement in ASHRAE Standard

Improvement in ASHRAE Standard 90/90.1 (1975-2013) with Projections to 2030. Courtesy of Pacific Northwest National Laboratory 2015

Let’s start with energy modeling, where change is coming for the better. In the past, the energy modeling community has been required to continuously respond to energy code cycle updates with new baseline models. That is, the bar for uncovering savings would be increased each and every time a new energy code was adopted. Following a code update, program staff and the energy modeling community would have to go through another learning curve to determine where to set a new bar and how to model the changes. (more…)

Access+Ability: An Evening at the Cooper Hewitt Museum

Students used props to simulate sensory and mobility disabilities.

As part of Cooper Hewitt Lab | Access Design Teen Program and the museum’s ongoing ‘Access+Ability’ exhibition (on view through September 3, 2018), the Design for Aging Committee of the American Institute of Architects (AIA), New York Chapter, was invited to facilitate a workshop with high school students to explore challenges experienced by seniors and people with disabilities. As an Accessibility Consultant here at Steven Winter Associates, Inc. and a member of the committee, I had the opportunity to attend the event.

Students at the hands-on workshop were challenged to develop design solutions to address the needs of a hypothetical group of older adults attending a lecture on the 3rd floor of the Cooper Hewitt Museum. Included among the hypothetical attendees were people with visual, hearing, and motor disabilities and those with limited knowledge of the English language.

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