How Proposed Building and Energy Code Changes Might Affect You

Rainbow-Plus-Stuppy greenhouse building codesOne of the primary roles of the National Greenhouse Manufacturers Association (NGMA) is to monitor building and energy codes as they apply to the horticulture and greenhouse crop production industries. Through its Codes and Standards Committee, NGMA proposes appropriate changes and clarifications, opposes proposals that have a negative impact on the industry, and provides resources for education and interpretation of the codes.

According to Matt Stuppy, President of Stuppy, Inc. and a member of NGMA’s Codes and Standards Committee, in 2019 there are two significant proposed changes to the International Energy Conservation Code (IECC) that greenhouse owners and operators should know about.


“These proposals take opposite viewpoints of greenhouses,” Stuppy says. “The first would potentially eliminate energy code regulation of greenhouses, and the second proposal adds more language, removes some greenhouse exemptions, and increases the risk for long-term impacts on the horticulture industry.”

The first proposal, known as CE6-19, is intended to restore the energy code to its original intent of regulating spaces for human comfort and occupancy. This change recognizes that some buildings use energy for industrial, production, and specialized processes.

Since the majority of greenhouse energy use is for growing and maintaining plants, NGMA notes that greenhouses should be exempted from all, or the majority, of the energy code.

“In the past, NGMA has worked to exempt the thermal envelope (glass, polycarbonate, acrylic, polyethylene coverings) of the greenhouse from the energy code,” Stuppy says.

NGMA will be supporting CE6-19 because it clarifies and minimizes the role of the energy code as it relates to greenhouses.

The second proposal, known as CE56-19 and proposed by the NW Energy Codes Group, will be opposed by NGMA. This proposal will put significant and impractical regulations on greenhouse growers. Some of the key problems with the proposal, according to NGMA, are:

  • Greenhouses will be grouped with sunrooms and skylights in the energy code
  • The greenhouse exemption for thermal envelopes in the energy code is removed
  • Required installation of internal energy curtains on all greenhouses without regard to the purpose and/or growing season for the structure
  • Required opaque, insulated walls and ends for greenhouses
  • Creates a negative perception that greenhouses are not energy efficient and should be further regulated

NGMA will oppose CE56-19 because it overreaches on regulating greenhouse energy and tries to lump every greenhouse together regardless of how it is used.

Detailed information can be found on the International Code Council’s website.

The energy conservation code will continue to gain adoption throughout the U.S. Greenhouse owners will continue to see the effects and requirements of the energy code impact their operations.

“Now is the time to protect the industry and make sure greenhouses are properly understood and the codes are correctly applied to different greenhouse applications,” Stuppy says.

To learn more about making your greenhouse energy efficient or to find out more about the NGMA, go to