The 2019 Energy Standards include new mandatory measures and different compliance requirements for additions and alterations. This section highlights the key changes from the 2016 Energy Standards. Prescriptive compliance requirements may be higher than mandatory requirements.
Walls with 2x6 insulation have a mandatory insulation requirement of R-20 or U-0.071 (§150.1(c)2).
New masonry walls are required to be insulated to levels required in Table 150.1-A or 150.1-B (see Chapter 3) (§150.1(c)5).
When an addition to an existing building adds a new dwelling unit, indoor air quality requirements of §150.0(o) apply to the new dwelling unit. This includes accessory dwelling units (§150.2(a)1Cii).
1. Additions greater than 700 square feet must meet quality insulation installation (QII) requirements (§150.1(c)1E).
2. Additions 700 square feet or less:
a. Ceiling insulation in an attic shall meets R-38 in Climate Zones 1 and 11-16 and R-30 in Climate Zones 2-10.
b. Radiant barrier must be installed in Climate Zones 2-15.
3. Existing wood-framed walls with siding (or cladding) that will not be removed require only cavity insulation of R-15 in a 2x4 wall or R-21 in a 2x6 wall. (Continuous insulation is not required.)
See Section 9.3.4 for more information about wall extensions and exceptions to continuous insulation requirements.