Next generation high-performance homes and buildings optimize operational cost-effectiveness, safety and security, sustainability, accessibility, functionality, productivity, historic preservation, and aesthetics to deliver a safe, comfortable, and sustainable indoor experience.1 Next generation building codes, such as Passive House and ASHRAE Standard 189.1, help inform the design and construction of these homes and buildings. These and similar codes have been adopted as stretch codes by states and are increasingly moving towards zero-energy status.
To achieve even greater energy efficiency, states and communities can promulgate a voluntary or mandatory "stretch" or "reach” energy code to supplement or overlay their base code, providing communities a code option that is typically 15-20 percent more energy efficient than the state’s base energy code. Stretch codes take many forms, from amended versions of the base code to original high-efficiency codes written by states themselves. And as stretch codes are updated by their governing bodies, some are gliding toward zero energy and emissions.
In the NEEP region, Massachusetts, Vermont, New York, Washington D.C., Maryland, and Rhode Island currently have voluntary stretch codes that municipalities may adopt to achieve energy efficiency and savings beyond their state base energy code. Some states and local municipalities require stretch codes for certain types of buildings or municipal financed projects, but most are voluntary and meant to encourage deeper energy savings. Some, like the stretch code in Massachusetts, are tied to incentives through state programs – see Massachusetts Green Communities Program. Check out NEEP’s Code Tracker to learn more about state-specific stretch codes.
Model building energy codes are rapidly approaching zero energy levels. The 2021 version of the IECC will include zero energy appendices for both residential and commercial homes and buildings and some states are developing their own zero energy codes to reduce energy use and carbon emissions.
Annual zero energy use is the future of building energy consumption and achievable today. Several model zero energy codes and programs exist that states and municipalities can adopt and states can even define their own zero energy provisions. Zero energy homes and buildings bring about massive energy savings, carbon emission reductions, and are a market driver towards a cleaner grid and grid-interactive efficient buildings.
Though there are different approaches to zero energy, the important thing to remember is this: zero energy codes must be low-load codes, meaning the demand from the home or building on the utilities must be as low as possible; the remainder of its energy consumption is then generated through renewables. Whether renewable energy is generated on or off-site, the general rule of thumb is that however much energy a building annually consumes from the grid, it must produce an equal amount of energy through renewables. Check out NEEP's Zero Energy Buildings Page for more information and resources.
- Guide to Passive House
- A Guide to Zero Energy Ready Homes
- Model Progressive Building Energy Codes Policy
- Rating Systems vs. “Stretch” Building Energy Codes
- Energy Efficiency and Resiliency Webinar
- Renewable Energy Code Provisions Handout