Structural Insulated Panels are they the sustainable solution to standard light framed load- bearing construction in New Zealand ?

Structural Insulated Panel Systems (SIPs)

Construction structure The panels are slotted together to form the structure of the building – without framing

Structurally Insulated Panel Systems (SIPs) Can be used as: Walls Floors Roofs Interior walls Additions to other construction systems Kingspan

Claims for SIPs by manufacturers and suppliers are similar Energy efficient Renewable Waste efficient Healthy

Systems of measuring sustainable building BREEAM EPBD BEPAC LEED GBP

Standard for measuring sustainable building Sustainable site planning Safeguard water and water efficiency Energy efficiency and renewable energy Conservation of materials and resources Material toxicity and emissions Waste reduction Indoor environmental air quality

Standard for measuring sustainable building Sustainable site planning Safeguard water and water efficiency Energy efficiency and renewable energy Conservation of materials and resources Material toxicity and emissions Waste reduction Indoor environmental air quality

Claims for SIPs by manufacturers and suppliers are similar Energy efficient Renewable Waste efficient Healthy Energy efficiency and renewable energy Conservation of materials and resources Waste reduction Material toxicity and emissions Indoor environmental air quality

Research Question Are SIPs the sustainable solution to standard light framed load-bearing construction in New Zealand?

New Zealand light timber frame house construction 90% of all new houses in NZ From softwood plantation timber Framing comprises 15-25% of the wall Treated with CCA Manufactured from 60% of the tree Large amount of waste generated Requires insulation Subject to settlement creating draughts

Structural Insulated Panels systems (SIPs) From fast growth plantation timbers Foam insulation from petroleum industry Comprises all of the wall excluding exterior cladding Timber panel and plastic foam are both chemically treated. Engineered wood panels use of 90% of the tree Very little waste generated Excellent insulation and air tightness capabilities files.servicemagic.com

Energy efficient Whole Wall Thermal Resistance of SIPs Compared to Light Timber Framing Whole wall r-value (K-m2/W) SIP Light timber

Renewable Timber is plantation growth – renewable Insulation can be renewable material Timber is plantation growth Insulation is recyclable but not renewable

Waste efficient Construction waste makes up 50 % of all landfill content, 38% is timber and wood fibre SIPs generate less waste –in primary processing stages –in secondary processing stages –in construction phase

Healthy Manufacturing health risks with both processes Construction health risks are reduced with SIPs SIPs construction is more air tight SIPs have greater thermal resistance Humidity control is easier with SIPs

Ecological/Environment Equity (society)Economic SUSTAINABILITY

Are SIPs the sustainable construction solution in NZ? Timber surplus Limited petrochemical industry Skilled labour shortages Relatively low cost of labour Inefficient transport network Timber shortage Petrochemical industry Skilled labour shortages High cost of labour Efficient land transport network Demand for reduced construction period

Conclusion SIPs are not currently the sustainable solution to standard light framed load- bearing construction in New Zealand

However….. blog.lewrockwell.com