U-Value Prescriptive requirements for Roofs & walls as per ECBC 2017

U-value

Thermal transmittance (U value) is the heat transmission in unit time through unit area of a material or construction and the boundary air films, induced by unit temperature difference between the environments on either side.Unit of U value is W/m2.K. U value for the wall/roof/glazing indicates its ability to transfer heat through conduction.

Following are prescriptive requirements for Roofs and Walls for ECBC compliance options:

a. ECBC Compliance

b. ECBC+ Compliance

c. Super ECBC Compliance

Prescriptive Requirements for ROOFS

Roofs shall comply with the maximum assembly U-factors in tables given below. The roof insulation shall be applied externally as part of structural slab and not as a part of false ceiling.

Roof Assembly U-factor (W/m2.K) Requirements for ECBC Compliant Building

Roof Assembly U-factor (W/m2.K) Requirements for ECBC+ Compliant Building

Roof Assembly U-factor (W/m2.K) Requirements for SuperECBC Compliant Building

Prescriptive Requirements for Opaque External WALLS

Opaque external walls shall comply with maximum assembly U-factors in the given tables below. These values are for above grade walls only.

Opaque Assembly U-factor (W/m2.K) Requirements for ECBC Compliant Building

Opaque Assembly U-factor (W/m2.K) Requirements for ECBC+ Compliant Building

Opaque Assembly U-factor (W/m2.K) Requirements for SuperECBC Compliant Building