Description

Recent changes to H1/AS1, the guidance document for Building Code clause H1 Energy efficiency, call for increased insulation in the exterior envelope of residential buildings.

H1/AS1 Table 2.1.2.2B - Minimum construction R-values for building elements that do not contain embedded heating systems establishes a minimum compliance requirement of construction R-value R2.0 for external walls across our six climate zones.

R-value is a measure of thermal resistance, expressed as m²K/W (square metre kelvins per watt), that defines the ability to resist the transfer of heat. Generally, this relates to the thickness, density and thermal conductivity of the insulation material.

Scope

In this article:

• R-values and thermal bridging
• Thicker insulation might be needed
• Accurate installation essential
• Insulate voids before flexible underlay
• A rigid air barrier could be installed