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Tag: Certifications & Programs

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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How to Implement an Efficient Lighting Strategy in a Multifamily Passive House

Walking the aisle of your favorite home improvement store, you’ll notice the wide array of options for very efficient light fixtures. Don’t be fooled – truly efficient lighting design is achieved through thoughtful layout and proper controls.

Hallway lightingA high performance building warrants an efficient lighting strategy. With so many efficient LED fixtures available on the market, individual fixture efficiency is rarely an issue. However, these fixtures are often placed in high concentrations or at a higher wattage than necessary to adequately illuminate a space. The result is high lighting power density (LPD), which is measured by dividing the total light fixture wattage in a room by the square footage of that room. Even with controls such as occupancy or vacancy sensors, high LPDs are especially energy intensive in frequently occupied common areas, e.g., corridors and lobbies of multifamily buildings, impacting the bottom line efficiency of all buildings.

Projects pursuing Passive House certification are impacted by an optimized lighting scheme more so than a code-built building. As the heating and cooling energy used in a Passive House building decreases due to an excellent thermal envelope, the ratio of lighting energy used increases. Reducing lighting energy use can drastically improve the building’s overall primary energy demand. (more…)

Multifamily Green Building Certification Program Comparison

If you’re designing and constructing multifamily buildings, chances are you’ve run into one of the many green building certification programs. Whether mandated by code, tax credits, your loan, or because you want to improve building performance, the differences between programs can be difficult to understand. One of the most frequent questions we help design teams answer is “which multifamily green building program should we choose?”

To help shed some light on the major green building standards, we’ve outlined some of the most important requirements for multifamily building performance that tend to differentiate the programs the most.

ENERGY STAR

Administered by the U.S. Environmental Protection Agency, ENERGY STAR is a free program that includes envelope, mechanical, and moisture management requirements. There are two pathways to certification – ENERGY STAR Certified Homes and ENERGY STAR Multifamily High-rise – based on the height of the building. In the near future these programs will merge into one Multifamily New Construction standard.

Although it isn’t considered a full green building program (it doesn’t address materials, site or water), ENERGY STAR is included in this comparison because several programs and standards reference it as a base requirement.

Energy Star comparison chart (more…)

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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Delos Headquarters Raises the Bar for Healthy Buildings

A team of SWA consultants recently had the opportunity to tour the newly constructed Delos Office Headquarters, located in the Meatpacking District of New York City. The office, which occupies the fourth and fifth floors of a ten-story building adjacent to the High Line, has obtained WELL Platinum certification through the International WELL Building Institute (IWBI), Petal Certification through the Living Building Challenge, and is currently pursuing LEED v4 Platinum certification through the US Green Building Council (USGBC). From the inception of the tour, it was clear that the space had exceeded the expectations of these certifications, and more.

Overview

Delos entrance with monitor and greenwall

Beside the entrance, a monitor displays live building stats and company announcements

Stepping off the elevator, occupants walk over a large metal grate designed to remove debris from shoes, preventing dirt and other particles from contaminating the floor. Then, upon entering the office, visitors are immediately greeted with an abundance of natural light and sense of biophilia. The office is enclosed by large glass curtain walls and filled with an array of plant life. Next to the entrance, a large monitor displays office conditions, such as temperature, humidity, carbon dioxide, and other levels affecting tenant comfort.

The main office area is largely free address, which means employees can freely move to where they feel most comfortable. Each desk is adjustable and includes a monitor, a temperature adjustable task light, and many other utilities that foster productivity. There are greenwalls placed throughout the office (22 to be exact), which are used to purify the air. Clean air is also distributed through floor diffusers and dirty air is removed through the ceiling. Additionally, it is noticeably quiet in the office; the mechanical systems are well insulated and there is a low level white noise sound masking system that lessens harsh noises.  (more…)

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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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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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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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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