Description

BRANZ modelling identified six areas for designers to focus on to reduce the carbon footprint of a new build. In the first of this series, we look at the practical considerations for designers using rule of thumb 1 Increase construction R-values.

Scope

This article includes:

What designers need to know

• Increase roof construction R-value
  • Available insulation is limited
  • Insulation thickness will mean changes
• Increase wall construction R-value
  • Framing size and exterior wall assembly
  • Wall framing ratio
  • Uninsulated areas of exterior walls
  • Insulation installation
• Increase slab-on-ground floor construction R-value
  • Slab edge insulation
  • Underslab insulation
  • Area-to-perimeter ratio
  • Effective thickness of external walls
  • H1/AS1 (5th edition) – walls and floors
• Increase window construction R-value
  • Window types
  • H1/AS1 (5th edition) – windows
  • Window-to-wall ratio and orientation
• Other considerations
  • Embodied carbon emissions
  • Airtightness
  • Indoor environment quality (IEQ)
  • Compliance methods