The National Building Regulations SANS 10400 require that all new and renovated buildings are thermally insulated to limit energy usage from heating and cooling. Compliance with section XA is achieved in one of three ways:
• Following the prescriptive tables for each climatic zone in South Africa, generally proven very conservative in nature.
• Having a competent person demonstrate that the annual energy usage and energy demand of designated building classifications does not exceed tabled design limits.
• Performing a rational design according to the reference building method, which demonstrates an equal or better energy usage outcome to the prescriptive method.
IsoBoard believe the most cost effective and beneficial alternative to the prescriptive tables is the rational design approach. Examples performed of various building occupancy classifications across all climatic zones demonstrate the benefits of rational design from a cost and flexibility point of view. The cost of performing a rational design will repay in savings for buildings of approximately 100m2 and more.