Party Walls

The envelope of a Passive House building is designed to be significantly airtight. Mechanical ventilation systems introduce fresh, filtered air and exhaust stale, contaminated air 24 hours a day—which is extremely important in maintaining optimal indoor air quality and occupant comfort.

As the saying goes, build tight and ventilate right.

When ventilation systems are designed correctly, but installed, commissioned, or operated incorrectly, the system ends up being leaky and inefficient and uses more energy than expected.

Project teams for Passive House buildings must find solutions for these implementation and commissioning hurdles, or the potential energy penalty can adversely effect the building’s high-performance design intent.

What happens when a Passive House construction expert and a commissioning engineer collaborate to find a solution to common ventilation system issues that cause excess energy use? We, the authors of this blog post, did just that!

Keep reading to learn about common construction issues with Passive House ventilation systems and five lessons learned based on our experiences in the field. (more…)

Falling costs and rising demand for clean energy have increased the specification and installation of solar photovoltaic (PV) systems worldwide. In NYC, Local Laws 92 and 94 require solar PV and/or green roofs on all new buildings and alterations where the existing roof deck is being replaced. Third-party commissioning increases the likelihood that a PV system will perform as designed throughout its lifetime and reduces poorly performing PV systems, which erode the bottom line and damage solar energy’s reputation. This is probably why the NYC Energy Conservation Code requires that renewable energy systems greater than 25 kW be commissioned (C408.2).

Many factors can affect a PV system’s power output. Let’s look at some reasons why output may be less than expected.

Design Flaws

Commissioning agents help prevent design flaws when brought onto the project early in the process. Here are a few common design flaws:

Electrical Issues: In traditional string systems, modules are wired in series to increase voltage, as shown. However, if too few or too many modules are wired in series, the voltage will be outside of an inverter’s input range and there will simply be no power output. If modules of dissimilar current are wired together output will be reduced since the current of a string is limited by the module with the lowest current.

(more…)

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.

(more…)

 

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:

(more…)

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:

• EPA’s Indoor Air Quality Guidelines for School Building Upgrades
• Operations & Maintenance Tools from the New York City Department of Citywide Administrative Services (DCAS) Division of Energy Management (DEM)
• EPA’s Indoor Air Quality Master Class Professional Training Webinar Series
• ASHRAE’s Advanced Energy Design Guide for K-12 School Buildings
• EPA’s School IAQ Assessment Mobile App
• USGBC’s The Center for Green Schools
• NIOSH’s Dampness and Mold Assessment Tool – School Buildings

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:

(more…)

Montgomery County, Maryland recently passed new green building requirements, including adoption of the 2012 International Green Construction Code.  Montgomery County was one of the first jurisdictions in the country to enact a green building law in late 2007. Now, county officials have repealed the original law and replaced it with Executive Regulation 21-15 that will likely reduce requirements for many new buildings.

New Requirements

There are some pretty big changes brought about by the new law, which took effect on December 27, 2017 and includes a six month grace period for projects already under design. New projects permitted after June 27, 2018 will need to comply with the following:

• Projects 5,000 gross square feet and larger must comply, lowered from 10,000 gsf.
• Buildings must meet the 2012 International Green Construction Code (IgCC), replacing the requirement that buildings must meet LEED Certified criteria.
• Residential projects under five stories must use ICC-700/NGBS at the Silver Energy Performance Level.
• R-2 and R-4 portions of Mixed-Use buildings may comply with ICC-700/NGBS and the non-residential portion shall comply with the IgCC or the entire building may comply with IgCC or ASHRAE 189.1
• R-1, non-residential and R-1/Mixed-Use projects may select IgCC, ASHRAE 189.1 or LEED Silver with eight points or more under the Whole Building Energy Simulation path.
• All buildings using the IgCC compliance pathway must achieve a Zero Energy Performance Index (zEPI) score of 50 or lower.

(more…)

The sunset date for LEED 2009 project registration has come and gone and all new LEED registrations (or existing registrations that will not submit for preliminary review before June, 30 2021) will fall under the V4 rating system. We are still seeing a trickle of requests for LEED 2009 compliance support for projects that were registered before the October deadline, but those are becoming few and farther between. At the same time, design and construction teams are still wondering what the differences are between the rating systems. So, we are highlighting a few changes to the commissioning requirements in LEED V4 BD&C about which Architects and Developers should be aware.

(more…)

What is Commissioning?

Many energy and sustainability programs, standards, and codes require commissioning, including LEED, ASHRAE 90.1, NGBS, IECC, IGCC, the PSEG and NYSERDA’s commercial performance-based incentive programs (see glossary below). As states embrace these codes and enforce commissioning requirements you may ask yourself: what is commissioning and why is it beneficial?

Commissioning agents provide third-party quality assurance throughout the construction process. They review design drawings and submittals, periodically inspect construction progress, witness functional performance testing of mechanical equipment, and ensure that the building staff is trained and ready to operate the equipment after it’s turned over. Commissioning agents work on behalf of the owner to ensure that the owner’s project requirements are met. Most importantly, commissioning improves construction quality and reduces maintenance and energy costs.

The benefits of commissioning are never more apparent than during a retro-commissioning project. While commissioning involves a third-party review of operation during the construction process, retro-commissioning is a third-party review of operations well after construction is complete. Some difficult retro-commissioning projects have shown us how valuable it is to resolve issues when the design intent is still clear (or clearer) – and while the construction team is still onsite!

(more…)