RESIDENTIAL BUILDINGS, ADDITIONS AND ALTERATIONS

2005 Residential Energy Standards.

All new low-rise residential construction and additions (i.e., new or newly conditioned space) must meet the overall energy efficiency requirements of the Residential Standards. Alterations that do not add conditioned space must meet all applicable mandatory measures. Alterations with new or replacement glazing must either meet prescriptive U-factors and SHGCs, or comply with the Residential Standards using performance method calculations.  Alterations with more than 50 square feet of new fenestration to existing buildings with more than 20% total fenestration (glazing area  to floor area ratio) must comply with the performance method.

• We will work with you on single family homes, duplexes and multi-family buildings; on any size residential addition, including legalizing a space not previously permitted; and on alterations in which new glazing does not meet the standard minimum fenestration values.
• We will discuss with you the specific trade-offs between insulation, glazing, shading, HVAC and water heater efficiencies, and the inclusion of special HERS measures to achieve energy compliance.
• We will perform an Existing+Addition+Alteration calculation when an addition or alteration will not meet the code by itself, allowing improvements to the existing house to count as credits toward, for example, an addition with large glass areas.

The 2005 Residential Standards include several important changes from the 2001 energy code:

• Time Dependent Valuation of electricity is now the basis of the performance approach. Peak electricity use (e.g., during summer afternoons) will be valued up to ten times more than off-peak usage. This pushes building designs even more towards reducing cooling loads.
• Multi-family buildings must be enormously more efficient because of a significant change in the rules that set the standard design energy budget. In addition, the previous loophole which gave free credit to central domestic hot water systems is gone. The net effect is that electric resistance heating is no longer possible for most projects.
• Lighting mandatory measures include the requirement that all general lighting fixtures either be fluorescent, or have occupant sensors or dimmers controlling them depending on the type of room; and that in kitchens, the total wattage from dedicated fluorescent fixtures must equal or exceed that of installed wattage from incandescent fixtures.