Party Walls

BACKGROUND

The multifamily building industry has adopted a best practice long touted by the building science community: continuous insulation at the exterior of the building. However, even in this ideal circumstance in which the insulation is installed flush and without gaps against the exterior substrate (concrete block or sheathing) with an air barrier applied to this substrate beforehand, the overall performance of the insulation will be vastly reduced by the installation of shelf angles.

Shelf angles (also know as relieving angles) are designed to support the expansion and contraction of the brick coursing; however, this presents a direct challenge to the continuity of exterior insulation. Standard design details interrupt the exterior insulation at every shelf angle, typically at every floor in line with window lintels. Since the shelf angle is made of steel, a highly conductive material, this interruption impacts not only the effectiveness of the insulation in general, it provides a considerable thermal bridge over the entire horizontal band of the building at every occurrence.

A recent article by Urban Green Council, “State Energy Code Clarification Will Stem Heat Loss through Walls,” made it clear that a continuous shelf angle has “about the same poor thermal performance as [an] exposed slab edge.” The full article can be read here.

 

SWA RECOMMENDATION #1: LIMITING SHELF ANGLES

Not all buildings require relieving angles. Building owners, architects, and structural engineers should first ask themselves whether relieving angles are necessary at all for the building being designed. If it is determined that these angles will be necessary, the next question the structural engineer should ask himself is what the minimum frequency necessary is to support the brick course. Generally speaking, buildings do not need one shelf angle per floor—despite this being common practice.

In addition to the aforementioned energy implications involved in specifying shelf angles, there are other benefits to eliminating these steel members when possible. The most obvious impact is on upfront costs. At approximately $25/foot of angle iron (via Union Iron Works), shelf angles for multifamily buildings in New York City can cost tens of thousands of dollars.

Upfront and operating (i.e. energy) costs aside, there is also the embodied energy of the material to consider. Not only does the manufacture of the steel angle contribute to its embodied energy, but also all of the energy used to transport these pieces to the project site. By reducing the need for the production of these angles, the overall energy expended to construct a new building decreases.

One additional consideration for owners is the maintenance required for shelf angles. The introduction of brick lintels creates an inherent and inevitable need for future maintenance. Since the cost of this upkeep is often considerable, owners may wish to use the opportunity to limit shelf angles during design to reduce long-term maintenance costs.

 

SWA RECOMMENDATION #2: OFFSETTING SHELF ANGLES

In addition to limiting their frequency, consider a shelf angle offset to further reduce thermal bridging. One such system that allows for this is manufactured by FERO called FAST (FERO Angle Support Technology).

FAST is designed to offset the shelf angle from the structural backing, allowing the insulation and air barrier installations to be more continuous. More information about this product can be found on their website.

SWA welcomes the input of design teams for other possible solutions to achieve a more continuously insulated wall. By accomplishing this, the building will have a truly continuous thermal envelope. As a result, thermal bridging will be eliminated along with the associated energy losses.

 

 

CONCLUSION

To implement best building practices, fulfill the continuous insulation requirements of certification programs, and comply with NYC Energy Conservation and Construction Code, SWA recommends limiting the number of shelf angles in the construction of the envelope. This will help limit upfront material and long-term maintenance costs.

SWA also recommends off-setting the shelf angle to reduce the thermal bridging these steel elements create. Fewer shelf angles means that there are less obstacles imposed on exterior insulation, resulting in less thermal bridging. Limiting the impact of shelf angles produces a more robust and insulated envelope that will, in turn, positively impact the energy performance of the building and comfort of its occupants.

SWA would like to thank Robert Murray for his assistance with this article.

Robert J. Murray, P.E., LEED AP, Principal
Murray Engineering, PC
307 Seventh Avenue, Suite 1001
New York, NY 10001
Telephone: 212.741.1102
Email: rmurray@murray-engineering.com

 

REFERENCES

1. Anderson, J., D’Aloisio, J. DeLong, D., Miller-Johnson, R., Oberdorf, K., Ranieri, R., Stine, T., and Weisenberger, G. “Thermal Bridging Solutions: Minimizing Structural Steel’s Impact on Building Envelope Energy Transfer.” American Institute of Steel Construction. Modern Steel Construction, 1 Mar. 2012. Web. <http://msc.aisc.org/globalassets/modern-steel/archives/2012/03/2012v03_thermal_bridging.pdf>.

2. FERO: Engineered Construction Technologies. Product Catalogue. Edmonton: FERO: Engineered Construction Technologies, 2014. Web. <http://www.ferocorp.com/pages/fast/fast.html>

Boston 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.

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!

Written by Katie Schwamb

The Lantern Organization’s Lindenguild Hall is a 104-unit multifamily residential project that provides permanent shelter for under-served populations in the Bronx. On-site supportive service programming, open-use learning and activity rooms, and outdoor leisure space provide an enriched living experience for tenants. Contributing to the programmatic requirements of both LEED® for Homes™ and NYSERDA’s Multifamily Performance Program (MPP), the building’s sustainable and energy-efficient design features include high-efficiency boilers, a high-performance envelope assembly, low-emission finishes, low-flow plumbing fixtures, and a water-efficient landscaping and irrigation system. While all of these design elements contribute synergistically to high-performance operation, there is one feature that distinguishes Lindenguild Hall from many other affordable and supportive housing projects in New York…its extensive photovoltaic (PV) array.

Located on the building’s high-albedo roof, this 66-module solar electric array captures energy to help power lighting, heating, and cooling systems within the building’s common spaces, while reducing overall demand on the city’s electrical grid. An advanced feature of Lindenguild Hall’s PV system is its capacity for online monitoring, which provides building managers with real-time results, including metrics for solar generation in kW (kilowatts) and the overall kWh (kilowatt-hours) generated to date. Availability of this data enables management to assess the positive impact of renewable energy systems on their building’s performance. Long-term implications of alternative energy production on building stock include reduced life-cycle cost and protection against municipal energy uncertainties. Though less quantifiable , installation of innovative green technology adds momentum to standardizing sustainability in affordable housing design.

Lantern Organization, a not-for-profit housing developer and service provider, operates by actively addressing housing needs and offering social initiatives to strengthen disadvantaged NYC communities. SWA’s Residential Green and Multifamily New Construction groups helped Lindenguild Hall navigate the LEED for Homes program and secure NYSERDA MPP incentive funds. Committed to delivering the greatest benefit to their residents, Lantern acknowledges the added value of incorporating green building features into their affordable projects. Increased energy efficiency and improved indoor air quality potentially translate to lower energy cost burden and decreased susceptibility to disease for low-income populations.

Part 1: Public and Common-use Areas

After years of inspecting multifamily housing developments across the country for compliance with regulatory requirements for accessible design and construction, our accessibility group has compiled a list of common violations – violations that could easily have been avoided before construction even began. By addressing requirements for accessibility in the early phases of a project, designers can preempt the need for costly remediation during construction and greatly reduce the possibility of potential litigation.

Here are just a couple of examples of common violations that we come across on a regular basis:

1. Slopes of Accessible Routes
   At least one accessible route is required to connect site arrival points, accessible building entrances, various site and building amenities, and dwelling units in the project. All too often, we arrive on site to find that the slopes of these accessible routes are not compliant (sometimes more than twice what is allowed), necessitating the ripping up of sidewalks and flooring materials – an undertaking that can quickly become expensive. When considering an accessible route, there are two important slopes to keep in mind: cross slope and running slope.

   — Cross slopes of accessible routes must be no more than 1:48 (2%). Areas where two accessible routes intersect, as well as the clearance at doors, must not exceed 2% when measured in any direction.
   — Running slopes of accessible routes must be no more than 1:20 (5%). If the running slope of an accessible route exceeds 5%, it is then considered a ramp and all ramp criteria apply, including the requirement for handrails on both sides of the ramp.

   By identifying the required accessible routes on the drawings, and providing notes and slope indicators along these routes rather than spot elevations, it is possible to greatly increase the chances of compliance once the concrete is poured and the building is constructed.

2. Protruding Objects
   

   Sconces are common examples of protruding objects.

   Accessible design isn’t just about ensuring equality for those with mobility impairments. Another important, and often missed requirement, applies to those with visual impairments. A protruding object can be something as basic as a wall sconce, bar countertop, or drinking fountain; and as seemingly innocuous as a piece of artwork on the wall. Any element that is located 27-80 inches AFF and projects more than 4 inches from a wall can prove hazardous to someone who does not have the ability to see it. The projecting objects themselves may seem small, but the cost of replacing hundreds of lighting fixtures throughout a building can be astronomical.

   While the best method of avoiding protruding objects is to specify wall-mounted sconces and other fixtures with a low profile, there will of course be situations that require other solutions. Where a protruding object exists, a cane-detectable barrier must be provided below it to ensure that a person with a visual impairment will be able to identify and avoid the potentially hazardous object. This can be as simple as positioning a planter or built-in piece of furniture below a wall sconce or piece of artwork, or installing a foot rail or knee wall below projecting bar countertops. Locating drinking fountains within alcoves is another method of achieving compliance.

By addressing these common violations in the design phase of a project, it is possible to greatly reduce the need for change orders and costly delays once construction begins. A little planning ahead can save a lot of time and money in the long run.

Stay tuned for Part 2: Dwelling Units – coming soon!

Whether code built or energy efficient, if your new home has a poured concrete foundation and floor slab, please pay particular attention to the following. While older, leaky homes result in low interior moisture levels (thus the desire for humidifiers on central furnaces); newer, tighter homes will typically have relative humidity levels in the 25-50% range naturally.

In some cases, there is a need to actually dehumidify to maintain relative humidity below 50% during the winter. In the first 1-2 years after the home is built, concrete foundations expel massive amounts of moisture as part of the concrete curing process called “hydration”. As the concrete cures, some of the water in the concrete mix reacts chemically with the portland cement and forms the hardened concrete, and some of the water evaporates to the surrounding air. The exterior water resistant/proof coating on the below grade portion of the foundation prevents moisture from escaping that way. Typically only a 1-2 foot tall area along the perimeter of the above-grade portion of the foundation is available for drying to the exterior.  It is more likely that the moisture will be expelled to the interior of the home and therefore, must be managed to prevent deleterious moisture-related problems such as condensation, mold, wood rot, etc.  Framing lumber also contributes: lumber that starts out kiln-dried at 18% moisture levels, will eventually end up at 6%.

How to deal with that moisture? Here is that cheap investment alluded to: an ENERGY STAR dehumidifier with a built-in humidistat.  This unit should be plumbed to a drain to allow continual operation (without having the occupants empty a bucket).  In addition, the dehumidifier should be installed in the basement or crawlspace as soon as the structure has been enclosed and power is available. In terms of the construction process, it is recommended that the foundation be the last item to be insulated to allow for the internal construction moisture to be removed prior to enclosing. After a year or two of occupancy, construction material moisture levels will become stabilized at “normal” levels. In the interim, remember to “build-tight and ventilate right”, but also manage that construction moisture.

 

Calendar year 2015 marks the start of the third year of mandatory Local Law 87 compliance in NYC. The Law—which requires buildings over 50,000 sq ft to conduct an energy audit and retro-commissioning study once a decade—has, to date, been characterized by market uncertainty and a somewhat hesitant response from the real estate community. These conditions stem largely from an unclear expectation as to what the future will hold, and what, if any, blow back there might be for being the owner of a poor-performing building.

This lack of clarity has created a wide diversity in the approach that owners opt to take in complying with Local Law 87. A notable pool of building owners, for example, have viewed the law as a burden enacted by NYC, and have opted to take the cheapest available, low-bidder approach to compliance. A large number of newly formed energy consulting firms have popped up to provide “cheapest-in-class” services, this despite the fact that many of these startup firms lack the qualifications and experience necessary to actually perform a compliant Local Law 87 project. As is almost always the case, you get what you pay for. On the other hand, a different set of building owners have viewed the law as an opportunity to improve the performance of their buildings by engaging the service of discerning engineering service providers. These owners see the value in having a 3rd party vet the operation of their buildings, as they realize that operational cost savings drop straight to the bottom line, driving improved NOI, increased asset value, while guarding against the risk of future volatility in the commodity markets.

The real estate community has, by and large, accepted Local Law 87 as a fact of life, but the lack of a clearly demonstrated vision of future goals has created a deeply fragmented understanding of how the Local Law 87 process can and will impact a building’s operation. Signs, though, are pointing toward a clarification of what this process will require into the future, and there is reason to believe that the lay of the land will be quite different in years to come. For starters, the DeBlasio administration, in the fall of 2014, issued their One City Built to Last plan. This ambitious plan provides a policy framework for achieving 80% emissions reductions in NYC by 2050—no small task, to be sure. The aggressive nature of the plan requires that the city dig deep into the performance of the built environment in order to achieve these reduction targets, as buildings account for about 70% of NYC emissions. The DeBlasio administration has taken a “carrots and sticks” approach toward compelling change and ensuring adherence to their agenda: state and local incentives have been dangled in front of the real estate community to encourage proactive adoption of energy conservation practices by building owners, while the not-so-thinly-veiled threat of future mandates loom on the horizon for those actors that fail to take appropriate action. As DeBlasio was quoted in a September Real Estate Weekly article, “For private buildings, we’ll set ambitious targets for voluntary reductions, but if steady progress is not made, we will issue clear mandates,ˮ said deBlasio, adding, “Our long-term goal is bolder still — charting a path to a full transition from fossil fuels.” Again…not so thinly veiled.

Notable carrots include limited time incentive programs, such as the Demand Management Program offered jointly by NYSERDA and ConEd, and the forthcoming establishment of a retrofit accelerator program, which will scrub Local Law 84 (benchmarking) and 87 data to facilitate engagement between key stakeholders as the City attempts to play matchmaker in a Love Connection style game of emission reduction through market transformation. Many in the real estate and sustainability arenas see great promise and opportunity in these models.

Love it or hate it, the real estate community and others need to acknowledge that the landscape is changing, and the vision of the future—at least as how Mayor DeBlasio sees it—is taking shape.
Early adopters of emissions reduction practices—e.g., buildings that participate in voluntary programs such as the Mayor’s Carbon Challenge and those that take a more rigorous approach to the Local Law 87 process—stand a better chance of avoiding the “heavy hand of government” that DeBlasio so publicly campaigned on. And they might even get to munch on a few carrots along the way.

We are thrilled to welcome Everyday Green to the SWA team! While working on green building projects in the Mid-Atlantic region over the past decade, I’ve consistently been impressed by their reputation for quality work and expertise. This is going to be a fantastic partnership at a time when the high performance buildings market is really taking off in Washington, D.C., Virginia, Maryland and Pennsylvania!

Allow us to introduce you to our new staff in the Mid-Atlantic Region:

Andrea Foss– Director of Sustainability Services – Mid Atlantic Region
Andrea will be Director of Sustainability Services—Mid-Atlantic Region. Andrea founded Everyday Green in 2008. She gained her in-depth understanding of green building working at the USGBC supporting the development of the LEED for Homes, Commercial Interiors, Core and Shell and Existing Buildings rating systems.

Scott Pusey – Senior Sustainability Consultant
Scott is trained and certified in advanced building science and building diagnostic testing. He is an expert troubleshooting energy efficiency problems and has extensive construction and site management experience.

Elliot Seibert – Senior Building Systems Engineer
Elliot is a mechanical engineer specializing in building science and energy efficiency. With ACCA training on mechanical systems design and performance, he specializes in assisting project teams with equipment selection and design.

Michael Feldman – Sustainability Consultant
Michael is a civil engineer specializing in building science and performance. With a broad background in traditional and green building concepts, Michael specializes in on-site verification of energy efficient building practices.

Corrie Weikle— Sustainability Consultant
Corrie is a sap for all things green and sustainable. She has a passion for guiding behavior change toward sustainable practices and has worked in both the non-profit and for profit industry developing resource conservation management (RCM) and environmental education programs.

Christopher Kramer– Sustainability Consultant
Chris is a HERS Rater and specializes in diagnostic testing and site inspections for new homes. Chris is also preparing to take his EIT certification exam.

(more…)

HUD’s 2015 Innovation in Affordable Housing student design and planning competition has hit full stride. Building on its successful inaugural run in 2014, this year’s competition has university representation from over 20 states. Strategic teams of 3-5 graduate students and a faculty advisor, primarily from architecture, urban planning, real estate, business, and environmental engineering programs, are challenged with redesigning a 300-unit senior housing property for the Houma-Terrebonne Housing Authority (HTHA). Competitors will craft actionable solutions that consider economic, social, and ecologic issues unique to the region’s affordable senior housing sector. Successful projects will address needs of senior residents (quality of life), site and building codes, finance strategies (incl. leveraging partnerships), integrated energy efficiency technology, and community connectivity. Following a rigorous review process, select finalists will travel to Houma, LA in March for a site-visit intended to prepare competitors for refining their final submission. The winning entry will be chosen by a judging panel of industry thought-leaders, and awarded $20,000 at a ceremony in Washington, DC ($10,000 to the runner-up).

Steven Winter Associates, Inc. (SWA) recognizes the critical need for global availability of quality, affordable housing. Our support of HUD’s competition will advance studies in this emerging market by initiating a new generation of student-professionals into the industry. SWA fulfilled a lead role in competition development, outlining the competitive structure, project submission requirements and guidelines, and final judging criteria. Additionally, SWA spearheaded all marketing efforts for the competition, including a robust registration outreach campaign consisting of email blasts, phone communication, social media, and direct mailing. Work on the IAH competition demonstrates the firm’s continued support of student and professional competitions, adding to past programming efforts with the SBIC’s Beyond Green™ High Performance Building Awards and the Housing Authority of Norwalk’s Affordable Housing Design Competition. The firm’s involvement reinforces SWA’s commitment to progressing innovation in high performance building practices, and validates SWA’s reputation as an industry authority on sustainable multifamily building science.

Visit the the #IAH2015 website here: bit.ly/IAH2015

Happy Holidays from the team at SWA!

 

SWA’s 2014 Holiday Video Message was created using a FLIR Exx-Series thermal imaging infrared (IR) camera.

It’s the most wonderful time of the year! We asked a few of our green living gurus if they could share some tips on how we can reduce our environmental impact this holiday season:

Decorating:

• Turn off your Christmas tree during the day. – Celeste M.
• Use LED lights, and put them on timers. – Gayathri V.

Feasting:

• Compost your leftovers from dinner. – Celeste M.
• Shop locally and bring your own tote bags to reduce packaging waste. I highly recommend local breweries and local farms. – Karla D.

Powering:

• Make sure to unplug chargers, lamps, and other miscellaneous appliances when not in use. Always unplug electronics as soon as they are fully charged; never leave rechargeable electronics plugged into power when they are fully charged. Your brand new holiday gadgets as well as your electricity bill will thank you! – Carmel P.
• Use rechargeable batteries in new toys. – Jordana V.

Giving:

• Use recycled paper for wrapping. – Celeste M.
• Recycle gift wrapping. – Jordana V.
• Buy gifts without much packaging. – Jordana V.

How are you going to make your holidays green? Do you have the ultimate green gift?