SANS 10400-XA

The implementation of SANS 10400-XA as part of South Africa’s National Building Regulations now requires new buildings conforming to the building energy efficiency requirements, as set out in the SANS 10400-XA and SANS 204 specification.

SANs 10400-XA comes as a result of severe pressure felt on the South African national electricity grid in the face of a growing demand on a supply that’s severely limited. Almost 60% of the world’s electricity is used by residential and commercial buildings, a statistic that makes the construction and building sector the single biggest contributor to greenhouse gas emissions.

It’s because of concerns about climate change and rising costs that energy is becoming a core focus in the way buildings are now designed. The majority of South Africa’s buildings were designed and built in a time when electricity was cheap, but constant price hikes are making them increasingly expensive to live and work in, and less affordable to their occupants.

There are three routes to compliance in the wording of the SANS 10400-XA Regulation:

1. Prescriptive route – by following specific necessities regarding the design and construction of the building, together with services such as the HVAC (heating, ventilation and air-conditioning) installation. The necessities for the services are in full detail in SANS 204. No rational design is required with this route.

2. Performance route – requires rational design by a competent person to demonstrate that the building’s theoretical annual energy consumption and demand do not exceed the values specified in the Standard.

3. Reference building route – needs rational strategy by an experienced professional to demonstrate that the building’s theoretical yearly energy intake and demand do not go beyond the values for a reference building that obeys with the necessities of the prescriptive route.

SANS 10400-XA is designed to ensure that all future houses comply with the minimum energy efficiency requirements to lower the overall energy demand of a building over its life cycle. The basic criteria are covered below:

Living spaces should face north to ensure the best orientation. This ensures rooms will be warmer in winter and cooler in summer. The longer axis of your house should run east-west. Roof overhangs should be used on the northern facades to protect windows from harsh summer sun. Based on the SANS 10400-XA regulation Western windows should be limited to avoid heat build-up in the late afternoons.

Under floor heating: The use of under floor heating will require a layer of insulation to be installed below the concrete surface bed achieving a minimum R-value as defined in SANS 10400-XA. This will prevent heat loss through the ground and will promote faster heating vertically into the room.

Greener methods of under floor heating should also be considered over traditional heating methods such as solar water under floor heating. Roof and Ceiling Insulation: Roof and ceiling insulation materials are now much thicker more efficient and need to achieve a minimum R-value as defined in SANS 10400-XA

Fenestration (Windows, Doors and Skylights):
Under the deemed to satisfy requirements of SANS 10400-XA fenestration areas are limited to 15 percent of the net floor area per storey. Exceeding this ratio will require a rational design by a competent person ensuring that all windows and doors comply with the maximum limits for solar heat gain and conductance in accordance with the requirements set out in SANS 204. In the case of a rational design, it will be most probable that higher performing glass such as low E or double glazing will be required in order to comply with the requirements.

If you are struggling to interpret SANS 10400-XA, don’t hesitate to contact us for help! SP Energy will provide energy audits to analyse where energy is being wasted. SP Energy will guide you or your management towards lower energy usage.