Almost 60% of the world?s electricity is used by residential and commercial buildings, making it a rapidly increasing and a pressing matter of concern. It?s due to the global climate changes and an increase in costs and energy consumption requirements that the need for energy efficiency and energy efficient buildings is being emphasized. ?70% of South Africa?s buildings were designed and built when electricity prices were economical, but the constant price hikes are making it not only hard to maintain a livelihood but also depleting the energy resources at a very rapid rate. Thus, the increasing burden on the South African national electricity grid forced the government to make amends and introduce The South African National Standard – SANS 10400 – XA?and the SANS 204 to regulate energy use and encourage energy efficiency in building for better utilization of resources and ensuring improvement in the ecological changes and declining ecosystems.
Energy efficient buildings, is a simple and very innovative idea to introduce required changes in the existing buildings and practical measures that save energy when new buildings are built and designed. ?With the introduction of new regulations and policy in the existing sans 204 and national building regulations, the government of South Africa is taking a step ahead towards making the country a cost-efficient country!!
Many modern and especially commercial buildings have been built without much consideration of passive design and rely strongly on technology such as Heating, Ventilation, and Air-Conditioning (HVAC) systems and electric heaters to provide a comfortable indoor climate. Using electricity for these functions is very inefficient and costly.
What Is SANS 10400 – XA?
The SANS 10400-XA standard is a summary of the SANS 204 and other standards into a single reference for homeowners to ensure compliance with the energy efficiency requirements of the National Building Regulations (NBR). ?These Requirements include:
- Buildings should face north so as to make most of the sunlight along with Suitable roof overhangs to maintain the adequate temperature during both summers and winters.
- Use of energy efficient heating, ventilation and air-conditioning (HVAC) systems wherever required; ?
- At least 50% of water heating must be done through a solar water heater or heat pumps or any other energy efficient manner.
The SANS 10400-XA is part of the National Building Regulations (NBR) and must be adhered to. Municipalities are responsible for assessing and approving development applications including their adherence to the NBR.
The SANS 10400?XA Regulations
The latest amends in South African National Building Regulations (NBR) list the following regulations and adherence to which is mandatory to all homeowners.
- XA1 ? all homeowners must use energy efficiently and reduce the greenhouses emissions and use energy within the given limits.
- XA2 ? not more than 50% of the annual volume of domestic hot water should be heated through electrical resistance heating, i.e., 50% or more of hot water used must be heated by energy sources other than electricity.
- XA3 ? compliance with the XA1 Regulations must be accomplished by one of three methods. If homeowners or competent party build in accordance with SANS 10400?XA, then the buildings will be ?deemed to comply? with National Building Regulation XA1.
Which buildings are affected by the SANS 10400 XA requirements?
Buildings that consume energy as a result of human occupancy are the main target of the new regulations. All new buildings must comply with these regulations, and any additions or extensions to existing buildings must be strictly made in compliance with the new regulations. If the existing building is unaffected by an addition, only the addition will have to comply with the regulations.
How is compliance achieved?
To avoid delays in achieving planning approval and receiving occupancy certificates, homeowners should communicate to their architects and the professional teams that the home must be designed in accordance with the SANS 10400?XA Regulations. Compliance with the SANS 10400?XA Regulations requires that the design of new buildings satisfy certain conditions. There are basically three routes by which homeowners can comply with the new regulations, these three routes are-
- The Prescriptive Route
- The Reference Building Route
- The Performance Route
The Prescriptive Route is generally available to all persons and will commonly be used for houses and smaller buildings. This route requires that a set of rules is adhered to for water heating, insulation and glazed areas, i.e., windows, glass doors, and roof lights.
Homeowners need to choose the most practical and cost-effective route, depending on their financial resources and project timelines.
What documentation must be completed?
Once the plans are ready for submission, the Appointed Person (or Responsible Person, if a professional has not been appointed) must inform the local authority and Building Control Officer which compliance route has been chosen, by completing a set of four documents (Forms 1 to 4). These forms can be downloaded from the SABS website (www.sabs.co.za).
FORM 1: DECLARATION BY THE HOMEOWNER FOR APPROVAL OF BUILDING CONSTRUCTION.
Mainly the roles and duties of the homeowner are discussed here. The competent person making a declaration wherein the means for SANS 10400 -XA regulations have to be satisfied.
FORM 2: APPLICATION FOR APPROVAL AS AN APPROVED COMPETENT PERSON.
In this step, the Competent Person agrees to take on full responsibility for all the energy-related duties in this section the competent must declare that he/she has the qualification, knowledge and contextual experience necessary for completing the work with compliance to the regulations.
FORM 3: DECLARATION BY A COMPETENT PERSON.
Under this the Competent Person is required, to make a declaration that the person is the best for the task at hand and has strictly adhered to the regulations. This form also has the second part which states the critical design information of building and its energy consumption.
FORM 4: CERTIFICATE OF COMPLETION BY OF THE STRUCTURAL, FIRE INSTALLATION OR FIRE PROTECTION.
Here, the Competent Person has to make sure that he/ she has completed and attested the Certification of Completion. It is also the responsibility of the approved competent person who will retain the role of seeing all the energy aspects of the project. ?
Option 1: Compliance through the Prescriptive Route
As compliance through the Prescriptive Route does not require the appointment of a Competent Person, it is likely to be the route most widely used in cases where the homeowner would prefer the simplicity of following the prescribed rules, rather than trying a more innovative approach to achieving energy performance standards.
What must be done to follow the Prescriptive Route?
To meet the minimum requirements of the Prescriptive Route, Schedule A of Form 1 must indicate that this route has been chosen, and the design must adhere to certain rules. This requires that decisions be made on the following:
1 Water heating: – The location, capacity, and type of hot-water installations must be planned to ensure that at least 50% of the water will be heated by means other than electrical resistance heating.
2 Insulation: – Insulation must be specified as follows
- Roof and ceiling insulation type and thickness.
- Hot-water pipe insulation thickness (only on exposed pipes).
- External wall insulation (only where external walls are non-masonry).
- Under-slab insulation (only where in-slab heating is installed).
3 Glazed areas: – The total glazed area as a percentage of the net floor area must be indicated ?
- If it is more than 15%, the glazed area must be designed to comply with SANS 204.
These are areas which have different climatic influence, and are tabulated below according to the different climatic zones in South Africa ranging from 1 to 9 these climatic factors must definitely be taken into account before selecting the route either prescriptive or reference building:
Option 2: Compliance through the Reference Building Route
If the Prescriptive Route requirements pose technical difficulties or are unaffordable, the homeowner may wish to pursue compliance through the Reference Building Route. This option permits a greater degree of flexibility and creativity, allowing the professional team to introduce innovative energy-efficient solutions to achieve an energy performance that is the same or better than that which would have been achieved by the strict application of the Prescriptive Route. The factors influencing the choice of this compliance route are:
- The scale of the home.
- The wanted aesthetics of the home.
- The ability set of the expert team.
- Client preferences and willingness to pay for energy modeling.
What does the Reference Building Route involve?
A Reference Building is initially designed according to the homeowner?s vision and needs, with all the elements required to comply with the Prescriptive Route being included. Thereafter, the design can be modified with recommendations from the professional team. The annual energy usage and demand is calculated and compared with the performance of the Reference Building (the base case). If the modified design shows an equivalent or improved energy usage compared with the Reference Building, it complies with the regulations.
What must be done to follow the Reference Building Route?
To meet the requirements of the Reference Building Route, the homeowner must appoint a Competent Person who, along with the architect, will ensure that the required documents are submitted to the local authority timeously. The homeowner must also sign the following two SABS forms before the plans can be submitted for approval:
- Form 1: ?Declaration by the person responsible for preparing an application for approval of the erection of the building in terms of section 4 of the act.’
- Form 2: ?Application for acceptance as an approved Competent Person in terms of Regulation A19.’
Case Study: Joe Slovo, Cape Town: Sustainable low-income settlement
The Joe Slovo settlement is situated in the suburb of Langa, 10 km east of the Cape Town CBD. The low-cost houses in the settlement include the following sustainable design elements in compliance with SANS 10400-XA
- Improved thermal performance of buildings through insulated ceilings, roof overhangs, and double story, duplex block design, i.e., reducing external wall exposure
- Improved energy services through energy efficient water heating through solar water heaters (150-litre low-pressure evacuated tube systems).
The images show the houses in Joe Slovo and conventional low-cost houses in Delft that were used to compare the impact of the sustainable features.
Solar water heaters- SWH were installed on all houses. A community survey conducted after occupation showed that the SWH were most appreciated measure. Prior to the installation households used an average of 8 kettles per day for water heating. Even on cloudy days in winter, the SWHs were found to produce 30 to 40?C warm water. ?
Energy Efficient lights -The houses were equipped with CFL lights. It is noted that safe disposal and replacement system is required to sustain this measure as poor residents may replace broken CFLs with cheaper incandescent light bulbs. ?
Thermal design features- The thermal design was optimized with the help of a computer modeling package. The houses are a double story and have shared walls reducing their exposure to outside air. Most houses are north facing with roof overhang shading windows on the top floor in summer.
So, from the overall discussion, we can conclude that energy efficiency has ?become of a requirement rather than just a choice the global greenhouse emissions are increasing day by day destroying the ecological balance , if these signs further ignored the world as we know it will deteriorate, ?However, successful government intervention plans policies regulation and increasing awareness has turned the tide and bringing in a new wave of change although the quantum of change is very small it is helping in spreading more awareness.
?It is important to note that the design and plans for extensions and Improvements of the above mentioned must be made in compliance with the newly set regulations. Usually, the SANS 10400 -XA serves the role of providing the ?energy requirements for a building for the compliance with National Building Regulations regarding energy usage while the SANS 204 is more concerned with specifying the actual design requirements so as to achieve the desired levels of energy efficiency in the long run to make sure easy sustainability because countries like South Africa which fall under the economically backward ?countries already have a very limited amount of resources and if the country continues to consume the resources at its current pace then in the next few decades South Africa will run out of energy sources and must depend on the underdeveloped renewable resources.
While there has been lots of regulations and policies, the response and awareness created through such plans and policies in South Africa is still very little. There is surely demand of more plans and policies and amendments in the existing SANS 10400-XA due to the in compliance and loopholes in the regulations. It is a very necessary and ideal time for intervention in averting such massive scale energy crisis. Reports and research have shown that the buildings are the largest consumer of energy, right after the construction sector in South Africa.
Thus SANS 10400-XA can be said to be a stepping stone in averting a massive energy crisis in South Africa although the SANS 10400 is an incomplete attempt and requires lots of revision and amendments in the foreseeable future it can be concluded that the SANS 10400-XA is definitely a founding stone in revolutionizing energy efficiency in buildings in South Africa.