## SECTION 120.7 –MANDATORY INSULATION REQUIREMENTS

Nonresidential, high-rise residential and hotel/motel buildings shall comply with the applicable requirements in Sections 120.7(a) through 120.7(c).

### (a) Roof/Ceiling Insulation.

The opaque portions of the roof/ceiling that separates conditioned spaces from unconditioned spaces or ambient air shall meet the applicable requirements of Items 1 through 3 below:

1. Metal Building- The weighted average U-factor of the roof assembly shall not exceed 0.098.

2. Wood Framed and Others- The weighted average U-factor of the roof assembly shall not exceed 0.075.

3. Insulation Placement- Insulation installed to limit heat loss and gain from conditioned spaces to unconditioned spaces shall comply with all of the following:

A. Insulation shall be installed in direct contact with a continuous roof or ceiling, that is sealed to limit infiltration and exfiltration as specified in Section 110.7. This may include but is not limited to placing insulation either above or below the roof deck or on top of the finished ceiling.

B. When insulation is installed at the roof in nonresidential buildings, fixed vents or openings to the outdoors or to unconditioned spaces shall not be installed. When the space between the ceiling and the roof is either directly or indirectly conditioned space, it shall not be considered an attic for the purposes of complying with CBC attic ventilation requirements.

C. Insulation placed on top of a suspended ceiling with removable ceiling panels shall not be used to meet the Roof/Ceiling requirement of Sections 140.3 and 141.0.

EXCEPTION to Section 120.7(a)3: When there are conditioned spaces with a combined floor area no greater than 2,000 square feet in an otherwise unconditioned building, and when the average height of the space between the ceiling and the roof over these spaces is greater than 12 feet, insulation placed in direct contact with a suspended ceiling with removable ceiling panels shall be an acceptable method of reducing heat loss from a conditioned space and shall be accounted for in heat loss calculations.

NOTE: Vents, that do not penetrate the roof deck, and are instead designed for wind resistance for roof membranes are not within the scope of Section 120.7(a)3B.

### (b) Wall Insulation.

The opaque portions of walls that separate conditioned spaces from unconditioned spaces or ambient air shall meet the applicable requirements of Items 1 through 7 below:

1. Metal Building- The weighted average U-factor of the wall assembly shall not exceed 0.113.

2. Metal Framed- The weighted average U-factor of the wall assembly shall not exceed 0.151.

3. ‘Light Mass Walls- A 6 inch or greater Hollow Core Concrete Masonry Unit shall have a U-factor not to exceed 0.440.

4. Heavy Mass Walls- An 8 inch or greater Hollow Core Concrete Masonry Unit shall have a U-factor not to exceed 0.690.

5. Wood Framed and Others- The weighted average U-factor of the wall assembly shall not exceed 0.110.

6. 'Spandrel Panels and Curtain Wall- The weighted average U-factor of the spandrel panels and curtain wall assembly shall not exceed 0.280.

7. Demising Walls-. The opaque portions of framed demising walls shall meet the requirements of Item A or B below:

A. Wood framed walls shall be insulated to meet a U-factor not greater than 0.099.

B. Metal Framed walls shall be insulated to meet a U-factor not greater than 0.151.

### (c) Floor and Soffit Insulation.

The opaque portions of floors and soffits that separate conditioned spaces from unconditioned spaces or ambient air shall meet the applicable requirements of Items 1 and 2 below:

1. Raised Mass Floors- Shall have a minimum of 3 inches of lightweight concrete over a metal deck or the weighted average U-factor of the floor assembly shall not exceed 0.269.

2. Other Floors-The weighted average U-factor of the floor assembly shall not exceed 0.071.

3. Heated Slab On Grade Floor-A heated slab on grade floor shall be insulated to meet the requirements of Section 110.8(g).

EXCEPTION to Section 120.7: A dedicated building used solely as a data center that has a total covered process load exceeding 750 kW.

NOTE: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.8, and 25943, Public Resources Code.