Highlights of US General Services Administration - GSA’s 2018 report: The Impact of High-Performance Buildings

Posted on 10/10/2018 12:02:58 PM By ASC

The Impact of High-Performance Buildings

(click to enlarge)

This report demonstrates how GSA’s high-performance buildings save energy, save water, cost less to operate, produce less waste, and have more satisfied occupants compared with typical buildings.”

To better understand Federal Policy in the areas of High Performance Buildings it is helpful to review agency, policy hierarchy and reference standards.

In December of 2007 Congress authorized the Office of Federal High Performance Buildings under the Energy Independence and Security Act (EISA) . The Office works to promote, coordinate and stimulate efficient building across the entire Federal government; that includes 400,000 owned and leased buildings containing over 3 billion square feet of space.  Various Executive Orders regarding requirements for Federal buildings evolved from ESIA.

GSA Hierarchy of Polices, Committee Structure, Guiding Principles, Standards and Tools for High Performance Buildings

(click to enlarge)

Key Findings of the Report

The study included 200 buildings over a three-year period, and is the first to combine an internal analysis of GSA buildings with comparisons to industry-accepted benchmarks

GSA is leveraging the results of this study to promote cost savings, technology advancement, and operational excellence in our nation’s federal buildings. Data collection efforts and publications of these findings are intended to demonstrate how federal, state and local agencies as well as the private sector can understand the benefits of tracking building performance and using the resulting data to drive building-and portfolio-level decisions.

Note: “In this study, high-performance buildings are federally-owned, GSA-managed buildings that meet the Guiding Principles for Sustainable Federal Buildings. Legacy stock buildings are federally-owned, GSA-managed buildings that have not been upgraded to meet the Guiding Principles.”

Data for five metrics were collected from fiscal Years (FY) 2015, 2016, and 2017.
(click to enlarge)

(click to enlarge)

The resulting building set included 100 high-performance buildings and 100 legacy stock buildings.

The FY 2015–2017 energy consumption data reported for each building was converted to British Thermal Units (Btu), then expressed in terms of average consumption per gross square foot per year: energy use intensity (EUI) The results indicate that GSA’s high-performance buildings are more  energy efficient than both its legacy stock buildings and commercial office building counterparts.

More specifically, over a three-year average:

  • High-performance buildings’ energy use intensity was 23% lower than legacy stock buildings
  • High-performance buildings’ energy use intensity was 43% lower than the CBECS benchmark
  • Legacy stock GSA buildings’ energy use intensity was 25% lower than the CBECS benchmark
  • High-performance buildings used 13.6 kBtu5 less energy per gross square foot than legacy stock buildings
  • High-performance buildings used 33.1 kBtu less energy per gross square foot than the CBECS Benchmark

Areas of High Performance Buildings improvements relative to Adhesives and Sealants

Since 2006, the Guiding Principles for Sustainable Federal Buildings have served as a common set of performance goals aimed at helping federal agencies reduce the total cost of owning and operating facilities, while improving resource efficiency and providing safe, healthy, and productive built environments. 2016 was the most recent update.

Energy Efficiency

With the issuance of Executive Order 13834: Efficient Federal Operations, agencies are to "ensure that new construction and major renovations conform to applicable building energy efficiency requirements and sustainable design principles; consider building efficiency utilize optimization practices; and annually assess and report on building conformance to sustainability metrics"

Updates on the case studies in this report included installing a variable refrigerant flow HVAC system, LED lights with daylight sensors and dimmers, a thermally-enhanced building envelope, a geothermal heat pump, and a rooftop photovoltaic solar electricity generation system

Energy Efficiency Guiding Principles

“Seek to achieve optimal energy efficiency and measure performance on a regular basis. Focus on reducing energy loads before considering renewable or clean and alternative energy sources. Use energy efficient products as required by statute”

A) Ensure:

  1. The building has an ENERGY STAR rating of 75 or higher, or
  • Energy use is 20%,30%below the FY 2015 energy use baseline, or
  • Energy efficiency is 30% better than the current ASHRAE 90.1 standard
  • Use energy efficient products, as required by statute [REQUIRED]

ASHRAE 90.1 (Referenced in the Guiding Principles)

Air Barriers

Infiltration/exfiltration rates

Reducing Air Leakage of the Enclosure

One of the challenges with many of the GSA and Federal buildings is their iconic architecture. This limits the number of projects where additional insulation and air sealing to the exteriorcan be utilized to achieve greater  air, moisture and thermal performance. Adding insulation to the interior may work in a Deep Energy Retrofit but is disruptive and likely to interrupt workflow. Sealing up window transitions and other air leakage areas found in demising walls from the interior also present challenges that may require relocating personnel.

Typical air leakage points in a structure

This illustration from Building Science Corporation helps understand typical air leakage points in a structure
(click to enlarge)

Typical areas of air sealing (infiltration/exfiltration) where adhesives and sealants are specified

Achieving airtightness requires attention to detail at all transitions and penetrations from design through construction. Installation of properly specified of adhesives and sealants are the connections necessary deliver compliant air infiltrations rates.

Continuous Air Barrier

ASHRAE 90.1 is the basis for energy code in non- residential (commercial) buildings.

The code requires that the building envelope be carefully designed to limit the uncontrolled air league in and out of buildings. In the report, Impact of Infiltration on Heating and Cooling Loads in U.S. Office Buildings, it is estimated that air infiltration is responsible for 33 percent of total heating energy loss.

In addition to continuous air barrier (and insulation), proper sealing for joints around fenestration, door frames, junctions between: walls and foundations, walls, walls at corners, structural floors or roof panels is required.

  • Proper specification for caulking/ sealant/adhesives rated for exterior use (water and solar resistant) is critical. Here are some additional references and considerations:
  • Sealing interior walls may require fire-rated (fire stopping) adhesives/sealants
  • Paintable sealants are recommended for holes in the enclosure
  • Check doors for proper seals along tops, sides and bottoms
  • Check windows cracks, detartrated caulking and adhesives as well as proper installation (over-seal/under-seal) and connections to other material components such as piping, wall to roof connections
  • A proper caulking, sealing agent rated for exterior use (water and solar resistant) should be used. If an interior wall is being sealed, a fire-rated caulking agent may be required.
  • Where sealing air leakage is not feasible without destructive renovation, consider aerosol sealant technology
    • The technology was adapted from an establishedprocess for sealing duct leaks. For envelope sealing, an aerosol sealant is sprayed into the space that is pressurized by fans installed in a hallway or an exterior door. As the sealant particles are forced through leaks, the sealant sticks to the edges of the gaps and gradually fills the openings.

A useful tool to estimate air leakage is from Oak Ridge National Laboratory is the Web-Based Energy Savings Calculator for Building Envelope Air Tightness
(click to enlarge)
(click to enlarge)

Conclusions and Recommendations

My work over the last 13 years has largely focused on driving high performance, sustainable, resilient, energy efficient, low carbon building concepts and policy for Federal and State governments as well as private sector projects. Concepts on how to deliver solutions for this policy include new construction and deep energy retrofits. The goal is to achieve maximum building energy efficiency performance with Zero Net Energy pathways.

This report certainly demonstrates actions and results that are a model for a High PerformanceBuilding for any commercial property. Part of this requires Benchmarking to establish an energy baseline.

Also key to developing High Performance Buildings is measurement & verification for the purpose of continuous improvement. The Energy Efficiency Program Impact Evaluation Guide from the State & Local Energy Efficiency Action Network (See Action) frames energy efficiency evaluation with a range of assessment studies determining the effects of an energy efficiency program. Evaluations can document program performance, operations, changes in energy efficiency markets, and cost-effectiveness. There are three broad categories of efficiency program evaluations: impact evaluations, process evaluations, and market evaluations.

Other Federal Energy Saving Programs Department of Energy

Investments in high-performance building infrastructure will save utility and operating costs.

The Guiding Principles for Sustainable Federal Buildings provide a framework for improvements that will save money and reduce resource use.

For individual buildings and campus facilities, it would be useful to schedule periodic compartmentalized field test for air and moisture performance to make sure the upgrades for a High Performance Building are functioning per owner requirements.

Meeting air leakage building code requirements is squarely in the adhesive and sealants realm of opportunity, especially in light of the increase of extreme weather events. It will be interesting to see more case studies to truly understand the role air sealing as related to air leakage and overall energy efficiency performance.

Finally, I refer you back to my blog on the importance of proper specification, installation and quality control/assurance of sealants and adhesives.

comments powered by Disqus