Party Walls

 

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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The number of multifamily residential projects targeting Passive House certification has been rising steadily over the past several years, bringing along many exciting challenges. This has been especially prevalent in New York City, where increasingly stringent energy standards and a desire for innovation have made designing to Passive House standards an attractive goal. As the number of these projects passing through our office continues to grow, we have discovered some important overlaps with one of our other consulting services – Accessibility Compliance.

In the United States, multifamily new construction projects consisting of four or more dwelling units are subject to the Fair Housing Act, as well as state, city, and local accessibility laws and codes. For the purposes of this blog we will focus on projects in NYC, although the majority of newly constructed residential projects across the country will be subject to some variation of the criteria discussed below, for both Passive House and Accessibility standards. With this in mind, we have chosen a couple of common problem areas that require particularly close attention. (more…)

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.

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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About a year ago, I worked along with other HERS raters and the North American Insulation Manufacturers Association (NAIMA, a.k.a. Insulation Institute) to conduct a study on the importance of insulation installation quality and grading.

RESNET, the nation’s leading home energy efficiency network and the governing body of the Home Energy Rating System (HERS® Index) established standards for grading insulation installation.

The grading is as follows:

Grade I— the best and nearly perfect install which includes almost no gaps or compression… what some would call “G.O.A.T.”
Grade II—allows for up to 2% of missing insulation (gaps) and up to 10% compression over the insulation surface area… what some would call “mad decent”.
Grade III—insulation gaps exceed 2% and compression exceeds 10%… anything worse and the insulated surface area is considered un-insulated.

Source: RESNET Mortgage Industry National HERS Standards

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At Steven Winter Associates, Inc., we support the whole building approach to design and construction by doing our best to ensure that projects meet sustainability, energy efficiency, and accessibility requirements, among other design strategies and goals. From our perspective, accessibility compliance is a key factor in determining whether a project is truly sustainable and efficient.

As an example, I was recently contacted by a New York City-based housing developer. They received a letter from an attorney stating that three of their recently constructed projects in New York City were “tested” and found to be noncompliant with the accessible design and construction requirements of the Fair Housing Amendments Act and the New York City Building Code. SWA toured the buildings and confirmed that the allegations were in fact true. We identified issues such as excessive cross slopes along the concrete entrance walk, the presence of steps between dwelling units and their associated terraces, the lack of properly sized kitchens and bathrooms, the lack of compliant clear width provided by all user passage doors, etc. It quickly became apparent to us and to the developer that the cost of the remediation required to bring the projects into full compliance would be astronomical.

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Over the last 10 years, we’ve seen great strides in the solar PV market in the United States. Between the federal tax credit and utility-sponsored incentives, the price to install PV systems came within reach of many homeowners. For others, eager to make a positive impact on the environment, power purchase agreements with solar companies and no up-front costs made it possible to utilize their roofs to generate electricity.

While the calculated cost-effectiveness of solar panels relies on the future price of electricity (which we can’t predict), we can confirm that they do deliver energy. In a very scientific study of exactly one home, owned by a SWA engineer, five years of generation data is available. Sure, it’s not the pretty Tesla roof, but these panels were installed back in November 2011. At 4.14 kW, with no shading and great Southern exposure, the panels were estimated to generate 5,400 kWh/year of electricity in New Haven, Connecticut (Climate Zone 5). The panels have exceeded expectations, generating on average, 6,200 kWh/year, which is roughly 70-80% of the electricity required by the 2,500 ft2 gas-heated home and its 4 occupants.

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Welcome to part three of the air sealing blog post series! In previous posts, we have reviewed the substantive changes in 2016 New York Residential and Commercial Energy Code, focusing specifically on the new blower door testing requirements. In this blog post, we’ll examine how these requirements stack up in comparison to green building certifications that we are already familiar with: LEED for Homes, LEED BD+C, ENERGY STAR® Certified Homes, ENERGY STAR® Multifamily High-Rise (ES MFHR) and Passive House (PH).

To make this easier to digest, we’ve divided this comparison into two parts – compartmentalization and building envelope. If you need a refresher on the difference between these two types of blower door tests, we recommend referring to the article “Testing Air Leakage in Multifamily Buildings” by SWA alumnus Sean Maxwell.

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Winter in the City

Wintertime in New York City: cold wind whips down the avenue and seems to follow you as you leave the frozen street and enter your building. The cold gust pulls the heat out of the lobby and even seems to follow you as you make your way up the building, whistling through the elevator shaft as it goes. The colder it gets outside, the worse it gets inside. Can’t somebody please make it stop? Is it too much to ask to be comfortable in your own lobby?

No, it is not too much to ask, and yes, we can help. It is 2016 and we have the technologies and expertise to better manage this all-too-common problem, but first we must examine what forces lay at the heart of the issue.

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The newly constructed five-story mixed-use building located at 1115 H Street, NE is raising the bar with a LEED for Homes Platinum certification in the works. Offering 16 high-performance condominiums with an array of sustainable practices, including environmentally preferable products, and water- and energy-conserving fixtures and appliances, the project is contributing to the rapid revitalization of the H Street Corridor neighborhood. Steven Winter Associates, Inc. supported the energy and green building goals for the project, including LEED certification.

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It has now officially been over one month since the 2016 NYS energy code went into effect. In a recent blog post, we covered some of the significant changes for residential buildings in New York. In this post, we will explore the substantive changes made in the commercial code section, particularly with respect to envelope and air barrier requirements.

As a reminder, in this post, we are referring to retail, commercial, or larger than three-story R-2, R-3, or R-4 buildings. New York buildings can choose between one of two compliance pathways: ASHRAE 90.1 2013 or IECC 2015, by applying the appropriate state and city amendments. Prescriptive as well as performance options are available, depending on the chosen pathway. (more…)