Strike Section R503.1.1 of the International Energy Conservation Code and insert new Section R503.1.1 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
Building envelope. Building envelope assemblies that are part of the alteration shall comply with Section R402.1.2 or R402.1.4, Sections R402.2.1 through R402.2.12, R402.3.1, R402.3.2, R402.4.1.1, R402.4.3 and R402.4.4.
Exception: The following alterations need not comply with the requirements for new construction provided the energy use of the building is not increased:
[Retain current exceptions 2 through 6 as they are in IECC 2015]
[Retain current Section R503.1.1.1]
Insert new Section R503.1.1.2 in the Energy Conservation Code-Residential Provisions to read as follows.
Additional Insulation Requirements for Level 3 Alterations affecting 80 percent or more of the aggregate area of the building. Existing exterior wall, ceiling, and floor assemblies that are not part of the scope of work of the alteration but are in an existing building undertaking a Level 3 alteration affecting 80 percent or more of the aggregate area of the building are required to comply with the following minimum insulation requirements:
Exception: Existing exterior walls where space constraints would make it impractical to meet this section without substantial reconfiguration of interior spaces or features.
Insert new Section R503.1.1.3 in the Energy Conservation Code-Residential Provisions to read as follows.
Air Leakage Testing.Level 3 alterations affecting 80 percent or more of the aggregate area of the building must comply with air leakage requirements and procedures per Section R402.4.1.2.
Strike Sections R503.1.2 through R503.1.4 of the International Energy Conservation Code in their entirety and insert new Sections R503.1.2 through R503.1.4 in the Energy Conservation Code-Residential Provisions in their place to read as follows.
Heating and cooling systems. New heating, cooling and duct systems that are part of the alteration shall comply with Sections R403.1, R403.2, R403.3 R403.4, R403.6, and R403.7.
Exception: Where ducts from an existing heating and cooling system are extended, duct systems with less than 40 linear feet (12.19 m) in unconditioned spaces shall not be required to be tested in accordance with Section R403.3.3.
Service hot water systems. New service hot water systems that are part of the alteration shall comply with Section R403.5.
Lighting. New lighting fixtures that are part of the alteration shall comply with Section R404.
Strike Section R503.2 of the International Energy Conservation Code in its entirety and insert new Section R503.2 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
Any nonconditioned or low-energy space, as defined in R402.1 that is altered to become conditioned space shall be required to be brought into full compliance with this code.
D.C. Mun. Regs. tit. 12, 12-I503