ASHRAE Standard 228: A Guide to Zero Net Energy and Zero Net Carbon Buildings

ASHRAE Standard 228 is a new standard that sets requirements for evaluating whether a building or group of buildings meets a definition of ZNE or a definition of ZNC during building operation.

The standard defines ZNE buildings as those that generate as much energy as they consume on an annual basis, while ZNC buildings generate as much energy as they consume on an annual basis, and also offset any carbon emissions that are produced.

Key features of ASHRAE Standard 228 include:

• Draws from ASHRAE Standard 105, among others, to address energy and carbon flows across a site boundary, their measurement, and their balance.

• Includes allowances for sites that lack opportunity to produce adequate renewable energy, while placing additional requirements on the use of external carbon and renewable energy in the calculation.

• Defines the calculation of energy in terms of source—a multiplier on the energy crossing the site boundary to include energy used or lost in extraction, generation and transit to the site.

• The main energy calculation is made in terms of annual average factors, but allowance is made for the calculation of individual hours where data is available.

Benefits of achieving ZNE or ZNC include:

• Reduced energy consumption and carbon emissions.

• Increased energy independence.

• Improved occupant comfort and productivity.

• Enhanced property value.

• Increased compliance with sustainability regulations.

ASHRAE Standard 228 is a significant step forward in the development of ZNE and ZNC buildings, and will hugely help to accelerate the transition towards sustainable development as the status quo.

It is perhaps the closest thing the building industry has to a universal measurement framework to determine whether a building is in fact as sustainable and carbon-neutral as it claims to be.

To learn more about ASHRAE Standard 228, please visit the ASHRAE site.