The 2013 Building Energy Efficiency Standards for residential buildings include increased efficiencies for several envelope measures, and there are improvements that have been made to better aid the designer, builder, and building official.
1. An updated equation to calculate the aged solar reflectance for cool roofing product, §110.8(i)2.
2. Mandatory minimum insulation levels installed between 2x6 inch and greater wall framing, §150.0(c).
3. Introduced assembly U-factor to meet the prescriptive insulation requirement, TABLE 150.1-A.
4. Increased the prescriptive requirement for low- and steep-sloped roofing products (cool roof) and removed the designations of roof weight, §150.1(c)11.
5. For alterations, a prescriptive tradeoff is allowed between insulation and cool roofs, §150.2(b)1H.
6. More efficient fenestration (lower U-factor) and higher levels of shading (lower SGHC) are required in specific climate zones.
7. Dynamic Glazing also known as smart windows can now be accounted for energy compliance.
8. Window Films can be used to meet the shading requirements for alterations to existing buildings.
Prescriptive component packages C and E have been removed. There is now only one prescriptive component package, Package A (previously component package D).