Tuesday, 7 February 2012

Construction Drawings Upload

To build a carbon neutral home, or at least one that approaches that title, insulation and air tightness in the building envelope is crucial.

Many months of planning and design have gone into these almost-final construction drawings.

Key features are:

  • The avoidance of thermal breaks in the roof and floor. 
  • Minimal thermal breaks in the walls (1.8m spans).
  • Minimum 120mm rigid foam insulation in walls, 150mm in roof and floor. (R38 walls & R46 roof/floor)
  • Exposed timbers where desired inside and where not up to 240mm of rigid foam insulation in walls and 270 in roof/ceiling.
  • Excellent ventilation of structural roof, wall and under floor spaces.
  • Thick foundation platform (240mm), well over building regulations for earthquake-prone Japan.
  • Exterior wall foundation overhangs.
  • Three vapor barriers in each wall, four in floor, five in roof (due to the layers of aluminium backing on the insulation panels and the house wrap).
  • Outer skin of plywood should almost double the earthquake rating of the timber frame which is already over specification with bracing.
  • Inside layer of plasterboard adds to insulation and sound barrier levels.