Intro

SANS 204 was published as a voluntary National Standard for “Energy Efficiency in Buildings” in October 2008 and updated in August 2010. It contains requirements that are higher than SANS 10400-XA and defines the minimum requirements that must be adhered to, to achieve a Green Building rating. Over the next 3-5 years the level in SANS 10400-XA will be increased to SANS 204 and it is therefore advised that future buildings are designed to SANS 204.

SANS 204 sets out the general requirements for achieving energy efficiency in all types of new buildings, both for naturally ventilated buildings and for artificially ventilated buildings.

Main objective

• To reduce operational energy use without reducing comfort
• Requirements are significantly more stringent than SANS 10400-XA
• Standard reduce the use of energy from electricity, gas, oil or other fuels in buildings
• Standard addresses energy use by the building’s services to operate it –does not include energy used in manufacturing / construction or energy use by portable appliances
• Drivers for energy use – comfort, safety and security – the right to live and work in safe environment
• SANS 204 is the minimum requirement for Green Star SA

The Standard addresses the following areas in buildings

• Site orientation
• Building orientation
• Shading
• Building design – floors, external walls, fenestration, roof assemblies, roof lights
• Building sealing – building envelope, air infiltration and leakage, permissible air leakage

SANS 204 can also be used as a guide for voluntary energy efficient retrofits of existing buildings in order to reduce energy usage and thus electricity accounts.

• Maximum energy usage demand per building classification (occupancy) for each climatic zone
• Maximum annual consumption per building classification (occupancy) per building for each climatic zone

South Africa has been divided into six climatic zones according to the humidity and temperature variations.

 





Maximum Energy Demand




Note:
The maximum demand shall be based on the sum of 12 consecutive monthly maximum demand values per area divided by 12 per square meter which refers to the net floor area.



Maximum Annual Consumption




Note :

1. The annual consumption per square metre shall be based on the sum of 12 months monthly consumption of consecutive months.
2. Non-electrical consumption, such as fossil fuels, shall be accounted for on a thermal equivalence basis by converting mega joules to kilowatt hours.

Applies to naturally and artificially ventilated buildings that have centralised HVAC systems. Passive building design is encouraged wherever possible and the efficient use of renewable energy is stipulated.
The standard is written to how one would actually construct a building:

• Site and siting (Orientation & shading)
• Building design (Foundation, floor, walls, fenestration, ceiling & roof)
• Building sealing (Envelope, air filtration & leakage)
• Services (Lighting, power, hot water leakage & appliances)

This section stipulates the total R-value that must be achieved by the foundations, floors, walls & roofing system.

Floors and solutions

• Perimeter insulation R-value = 1.0
• Exception1: buildings greater than 500 m2
• Exception 2: Climatic Zone 5
• In-slab heating – insulated with R-value = 1.0
• Water resistant
• Continuous
• Perimeter insulation – suspended floor
• Climatic Zones 1 & 2 – R-value = 1.5
• Climatic Zones 3, 4 & 6 – R-value = 1.0
• In-slab heating – R-value = 1.0

• Climatic Zones 1 & 6 Total R-value = 2.2
• Climatic Zones 2, 3, 4 & 5 Total R-value = 1.9

Insulation shall:

a) be protected against the effects of weather and sunlight,
b) be able to withstand the temperatures within the piping


All chilled water, hot water and refrigeration piping, conditioned air duct work and flexible ducting shall be insulated to limit heat gain/loss to not more than 5% from source to furthest point of delivery on a system.