INDUSTRY FOCUS basic overview of energy efficienct building regulations
INDUSTRY FOCUS basic overview of energy efficienct building regulations
The government introduced its energy efficiency regulations for new buildings in November
2011 .
The aim was to reduce the energy consumption of buildings so as to relieve pressure on the national grid and reduce carbon emissions , and as a general contribution to environmental sustainability . The regulation , known as SANS 10400 XA , covers hot-water heating efficiency , the efficiency of the building envelope , and services like lighting that utilise energy . These regulations apply to all new buildings and alterations , and there are some differences in detail depending on where the building is situated . There are six climatic zones in South Africa based on the climate characteristics of the area .
WATER HEATING
The regulations require that half the hot water used in a building must be heated by efficient methods like solar heating or heat pumps . All hot-water pipes must be clad in a suitable insulating material with a specified R-value ( thermal resistance ) relative to the pipe diameter . All hot-water supply pipes must be connected in a ring main format that forms a continuous loop to and from the geyser . This reduces the time it takes for the water to get hot when you turn on a tap , thereby reducing water and energy wastage .
BUILDING ENVELOPE
The building envelope requirements cover the elements that make up a building , and the orientation of buildings relative to the direction of the sun .
Orientation
In order to reduce the need for heaters in the winter and air conditioning in the summer , the main living areas should be carefully designed to face north , so as to maximise sun in winter , and should be fitted with good overhangs to prevent the higher altitude summer sun from reaching the windows . The exact orientation and size of overhang can be worked out from readily available tables and software . Obviously , some rooms will have to face south , but these should be rooms that are not used often , like spare rooms , storage rooms and even bathrooms .
Floors
If underfloor heating is used , the regulations require an insulating layer with an R-value of not less than 1 . It is advisable to use insulation regardless of whether underfloor heating is to be installed or not , as a lot of heat can be lost through the floor and into the ground below . This insulation is usually in the form of rigid polystyrene boards laid on the ground before the concrete floor is cast .
Walls
The composition of the external walls of a