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Increasing Energy Efficiency in Buildings with Stretch and Reach Codes

Brent Trenga

The construction and building industry has taken steps to reduce CO2 emissions and mitigate the effects of climate change, but industry leaders should be ready to take these efforts further through stretch and reach codes.

According to the Building Codes Assistance Project (BCAP), the goal of both stretch and reach codes is to pull the construction market upward, priming the industry for changes that could be part of the next update for the state baseline energy code.

According to the BCAP, stretch codes are a voluntary appendix to a mandatory statewide minimum energy code that allows municipalities to adopt a uniform beyond code option to achieve greater levels of energy efficiency. Reach codes are a set of statewide optional construction standards for energy efficiency that exceed the requirements of the state’s mandatory codes.

Benefits of adopting a stretch code include: a winning solution for cities, the building industry and utilities; putting cities and states on the path to achieving zero carbon emissions from the building sector; reducing building energy use and costs; exercising flexibility and creativity in the way one adopts the codes.

States Adopting Stretch Codes

In 2015, Gov. Andrew Cuomo helped the State of New York establish a roadmap toward a clean, resilient and affordable energy system for the state. To help achieve these ambitious goals, the New York State Energy Research and Development Authority (NYSERDA) led an effort to develop NY Stretch-Energy, a voluntary, locally adopted stretch energy code which offers municipalities a more energy-efficient alternative to the minimum state energy code. The plan includes three quantifiable targets to achieve by 2030:

  1. A 40 percent reduction in greenhouse gas emissions from 1990 levels
  2. Sourcing 50 percent of energy purchases from renewable sources
  3. A 23 percent decrease in building energy consumption from 2012 levels

Rhode Island adopted a stretch code in 2017 with the desired outcomes of promoting energy-efficient homes, assisting with construction of net zero energy homes, expanding the installation of renewable energy systems and constructing healthy homes. The development was part of Governor Gina Raimondo’s Executive Order 15-17, which set robust energy reduction targets and clean energy goals for state agencies consistent with her “Lead By Example” initiative and broader policy goals that include clean energy industry and job growth.

Moving Beyond ASHRAE 90.1

ASHRAE 90.1 is the international standard that provides minimum requirements for energy-efficient designs for buildings (with the exception of low-rise residential buildings). The Portland, Ore.-based New Buildings Institute (NBI) has released a set of stretch codes designed to deliver a 20 percent performance improvement for commercial buildings over the ASHRAE 90.1 baseline. A summary of the new Model Stretch Code can be found at newbuildings.org/resource/model-stretch-code-provisions-20-percent. Any city or state can adopt the measures in full or adopt portions into their existing codes.

NBI’s stretch codes target five areas:

  1. Improved building envelope performance: this includes increasing window assembly performance, reducing solar gain, increasing insulation levels in opaque buildings, reducing heat transmission losses resulting from uninsulated building elements, and improving air barrier performance to reduce energy loss and moisture transmission.
  2. Lighting system performance: increased use of LEDs, increased daylighting and more efficient technologies for exterior spaces.
  3. HVAC improvements: reducing fan energy use and incorporating heat recovery into ventilation systems.
  4. Domestic hot water: reduce supply run length and volume to reduce standby heat loss, as well as incorporating waste heat recovery or solar thermal systems.
  5. Plug and equipment loads: deploy the most energy-efficient appliances and incorporate strategies to ensure that equipment is turned off when not in use.

Stretch and reach codes are an effective way to exact real change in reducing energy demand and greenhouse gas emissions. The construction and building industry—which is responsible for nearly half the CO2 emissions in the U.S.—should be prepared to embrace and adapt to the code changes.


Brent Trenga, LEED AP BD+C, WELL AP, is building technology director for Kingspan Insulated Panels North America, Deland, Fla. His background as an architect, construction manager, developer and project owner give him a unique perspective on all facets of the construction industry. Trenga leads Kingspan North America’s material health and transparency program and Kingspan’s North American NZE 2020 program, while collaborating with the company’s global healthy building team. Trenga can be contacted by email at brent.trenga@kingspan.com.