The energy efficiency legislation for new buildings SANS 10400-XA has been published by the regulator (NRCS). All new buildings will have to comply with the performance parameters, which means that insulation will have to be installed to achieve the stipulated R-values.

Compliance

• Adhering to the requirements of all the prescriptive regulations, or
• Complying with all functional regulations by:

• Adopting building solutions that comply with the deemed to satisfy requirements of the corresponding part of SANS 10400
• Reliably demonstrating or predicting with certainty that an adopted building solution has an equivalent or superior performance to a solution that complies with the deemed to satisfy provisions. (Rational design by competent person)

• Option 1: Rational design
• This alternative requires input of a professional “competent” person
• Thermal performance of building needs to be calculated
• Performance should be equal or better than specified in SANS 10400-XA

• Option 2: Compliance to SANS 10400-XA
• “Recipe” for building elements
• Requirements partially aligned with SANS 204

• Option 3: Compliance to Tables
• Thermal performance of building needs to be calculated
• Max Energy Consumption and Max Energy Demand must comply with tables in SANS 10400-XA
• This alternative requires input of a professional “competent” person

• Option 4: Comparison with a compliant theoretical (reference) building
• Building design performance – theoretical max energy consumption and demand shall be less than or equal to that of a reference building
• Building should be designed to “Deemed to Satisfy” standards
• Use of thermal performance calculations software accredited by Agrement SA
• This alternative requires input of a professional “competent” person

Additional Requirements

• Competent person (where necessary) – Submit documentation
• Local authority as per SANS 10400-A
• On Plans
• Where provided – location, type and capacity of water heating installations
• Where provided – details of
• Fenestration
• Insulation

Building envelope requirements SANS 10400-XA "Deemed to satisfy"

• Conceptually based on two principles:
• Maximum energy demand per unit area(kVA/m2)
• Maximum annual energy consumption per unit area (kWh/m2.a)
• Dependent on building classification and climatic region
• Design assumptions are given in SANS 10400-XA (4.3)

Compliance to NBR-XA-XA3

1. Rational design
• This alternative requires input of a professional “competent” person
• Thermal performance of building needs to be calculated
• Performance should be equal or better than specified in SANS 10400-XA
2. “Deemed-to-satisfy”
• Compliance with requirements in SANS 10400-XA
3. Comparison with a compliant theoretical (reference) building
• Energy usage of building shall be less than or equal to that of a reference building
• Reference building should be designed to “Deemed to Satisfy” standards
• This alternative requires input of a professional “competent” person

Energy Usage and Building Envelope – XA3

• Orientation (Guideline) SANS 10400-XA
• Compact in plan with most glass on the northern side
• Living spaces on northern side
• Longer axis of dwelling to be east-west
• Roof overhang to shield northern windows in midday summer sun

• Shading SANS 204
• Requires a permanent feature which extends horizontally on both sides of the glazing for the same projection distance
• Have and external shading device which is capable of restricting at least 80% of summer solar radiation

• Floors SANS 10400-XA
• If under floor heating is installed the floor slab must be insulated with insulation with a minimum R-value of 1.00

• Fenestration (Windows/Glass doors/Skylights) SANS 10400-XA + SANS 204
• Buildings with up to 15% fenestration area per storey
• Buildings with fenestration area per storey exceeding 15% shall comply with the requirements for fenestration in SANS 204
• Air leakage should comply with SANS 613

• External Walls SANS 10400-XA
• Light weight (Non brick/Non concrete) walls must achieve a minimum R-value:
• of 2.2 for climatic zones 1&6
• of 1.9 for climatic zones 2,3,4&5

• Masonry walls (Brick/Concrete) must achieve a minimum R-value of 0.35
• Double skin brick with no cavity, plastered internally and either plastered externally or finished with face bricks
• Single brick/block with a minimum thickness of 140 mm plastered internally and externally

• Roof and Ceiling SANS 10400-XA
• Must achieve the minimum total R-value specified below:

Services Lighting and power

• Depending upon occupancy and activity, the minimum lighting levels shall be determined in accordance with the requirements of SANS 10114-1 and SANS 10400-0
• Designers are encouraged to use daylighting in their designs to reduce that energy used
• The energy demand (power) and energy consumption for the building shall be determined in accordance with the requirements given in SANS 204

  Mechanical ventilation and air conditioning

• Air conditioning or mechanical ventilation systems (or both) installed in buildings shall comply with the relevant national legislation
• The air conditioning or mechanical ventilation system (or both) shall be designed to best practice
• Designed that in the event of failure of an air conditioning or mechanical ventilation system (or both). An alternative means of natural ventilation shall be provided
• All chilled water, hot water and refrigeration piping, conditioned air duct work and flexible ducting shall be insulated to limit heat gain or loss (or both) to not more than 5% from source to furthest point of delivery on a system

Hot water supply requirements SANS 10400-XA

Geysers-XA2

• A minimum of 50% of the annual average heating requirement for hot water must be provided by means other than electric resistance heating (Geyser) or fossil fuels
• See options below but not only limited to these:
• Solar heating
• Heat pumps
• Geothermal heat
• Renewable combustible fuel
• Heat recovery from alternative systems and processes
• The functional requirements of sub-regulation XA2 shall be satisfied when:
• 4.1.1 The population for which such building is designed is determined in accordance with Regulation A21;
• 4.1.2 The hot water demand is determined in accordance with table 2 and table 5 of SANS 10252-1:2004;
• 4.1.3 The storage requirement is based on maintenance of a hot water temperature of 60 0C;
• 4.1.4 Solar water heating systems shall comply with SANS 1307, SANS 10106 and SANS 10254 based on the thermal performance determined in accordance with the requirements of SANS 6211-1 and SANS 6211-2.
• 4.1.5 All exposed hot water service pipes (SANS 10252-1) shall be clad with insulation with a minimum R-value in accordance with SANS 204.
• 4.1.6 Thermal insulation, if any, shall be installed in accordance with the manufacturer’s instructions.

• Must be insulated with a minimum R-value of 1.00

• Must be insulated with a minimum R-value of 1.50