What are the new Energy Efficiency regulations (sans 10400 xa) and how do I comply?


Under the recently instated SANS 10400 XA building regulations, all new buildings need to meet specific energy efficiency criteria before being approved for construction.

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. 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 10400XA


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.


Air Infiltration:

All windows and doors shall comply with the max air infiltration standards as set out in sans 613. Consider the use of energy efficient frames such as aluminum, thermally broken aluminum, timber or uPVC. Open combustion fireplaces require a flue cap that can seal the flue from drafts when not in use.


External Walls:

The use of lightweight non-brick, non-concrete bricks will require a min R value as outlined in SANS 10400 XA. The use of a double skin masonry or concrete brick wall with no cavity plastered internally and externally or finished in a face brick externally will comply with the requirements setout in SANS 10400 XA. The use of a single brick masonry or concrete brick wall (Min 140 mm) plastered both internally and externally will comply with the requirements setout in SANS 10400 XA. Should you wish to comply with the best practice regulations set out in SANS 204 then the use of a cavity wall filled with insulation will be advised.


Hot Water Supply:

A minimum of 50 percent of the annual average heating requirements for hot water must now be provided by way of an alternative energy source other than electrical heating or fossil fuels. Examples are solar heating, heat pumps, geothermal heat, renewable combustible fuel and heat recovery systems. All hot water storage units shall maintain water at 60 degrees Celsius. All exposed hot water supply pipes shall be insulated with a minimum R value as required by SANS 204.


Services – Lighting And Power:

The use of natural light is highly encouraged to reduce the reliance on artificial lighting. Depending upon occupancy and activity, the minimum lighting levels shall be determined in accordance with the requirements. The energy demand and energy consumption for the building shall be determined in accordance with SANS 204. This implies that the number of light fittings in the building may be limited or the type of light fitting may need to be more energy efficient in order to comply with the max energy demand and consumption.


Mechanical Ventilation And Air Conditioning:

All air conditioning or ventilation systems shall comply with the relevant national building regulations. Such systems shall be designed that in the event of failure of one of both systems that an alternative means of natural ventilation is allowed for. All chilled water, hot water and refrigeration piping, conditioned air ducts and flexible ducting shall be insulated to limit heat gain or loss to not more than 5% from the source to the furthest point.


What Is A Competent Person?

According to the National Building Regulations, only a competent person is capable of undertaking the necessary requirements for compliance with sans 10400 XA. A competent person is defined as a person who is qualified by virtue of his education, training, experience and contextual knowledge to make a determination regarding the performance of a building in relation to the National Building Regulations.

As professional architects we have full capacity to act as competent persons on your project to fulfill the necessary energy efficiency requirements. We will therefore design your building whilst simultaneously ensuring compliance with the energy efficiency regulations. Clients will receive a report outlining all energy calculations for their peace of mind. Both Fritz Metz and Leani Metz from Metz Architects are registered competent persons with the NRCS. All competent persons must be registered on the local authority building control website before being able to submit drawings for approval.


We are fully SANS 10400XA and SANS 204 compliant (Energy Efficiency in buildings).