The main objective of SANS 204 is to reduce electricity consumption in buildings without reducing comfort levels.

The voluntary national standard for Energy Efficiency in Buildings was published in October 2008 and updated in August 2010. Called SANS 204, these standards define the minimum requirements that need to be met to receive a Green Star SA rating.

The main objectives of SANS 204 are to provide more stringent requirements than SANS 10400-XA and to reduce electricity consumption in buildings without reducing comfort levels. The following areas in buildings are addressed in SANS 204: site orientation, building orientation, building design, building sealing and shading. Flooring falls within the building design area and the right flooring system can contribute to maximising the energy usage demand per building classification.

South Africa has been divided into six climatic zones according to temperature and across different parts of the country. The maximum energy demand per building classification for each climatic zone can be determined according to the description of the building and the classification of occupancy of the building.

A second method of complying with the SANS10400 XA regulations is available by way of rational assessment. This means that check-box insulation and fabric requirements are waived and software is used to predict a building’s energy use. As long as software predicts that the building will use less energy than the abovementioned allowances, it will meet the regulations. For more information on the rational assessment, visit www.sans10400xa.co.za.

The total R-value that has to be achieved by the foundations, floors, walls and roofing system can be reviewed in the standard. The perimeter insulation R-value for floors is 1.0, except in buildings that are greater than 500m2 or buildings that fall within Climatic Zone 5 (sub-tropical coastal areas such as St. Lucia, Richards Bay, Durban, Port St Johns and East London, among others). These insulation values are only required if underfloor heating is used. If underfloor heating is not used, there is no requirement for insulation of the floors.

The perimeter insulation for suspended floors in Climatic Zones 1 and 2 (cold interiors and temperate interiors) is 1.5; in Climatic Zones 3, 4 & 6 (hot interiors, temperate coastal and arid interior) it is 1.0 and in-slab heating requires an R-value of 1.0. These values only apply if underfloor heating is used.

Various documents related to SANS 10400 and SANS 204 can be downloaded for free at http://sans10400.co.za/

Full thanks and acknowledgement are given to Solid Green and www.greenability.co.za for the information contained in this article.