If thermal ceiling insulation and high-performance window systems were introduced today into all new residential and commercial buildings, an estimated 3500 MW in electricity could be saved by 2020. This is almost twice the electricity currently produced by our only nuclear power plant, Koeberg (1800 MW).
This is the main point underlying the recent publication of SANS 204, Energy efficiency in buildings: a huge reduction in energy consumption, equivalent to a new nuclear power plant.
This can be achieved by introducing sensible and practical measures that save energy when new buildings are designed and built accordingly. And by ultimately making the three parts of this standard mandatory, the government will slowly but surely begin to achieve savings in energy and savings in the costs of providing that energy.
Solly Peter, Manager of Construction Standards at the SABS commented: “After years of very hard work, the standard has at last been published. Many thanks to all who helped produce its three parts, especially Howard Harris, Dr Sidney Parsons of the CSIR, who started coordinating this work, and Lisa Reynolds, who completed it. While limited space does not permit me to list everyone and their many diverse contributions, a very big thank you to you all.”
Lisa Reynolds, who currently chairs the Working Group responsible for the standard, commented as follows about SANS 204.
“Following the publication by the DME of their strategy for energy efficiency in 2004, the need for a standard to achieve this goal in the building sector became obvious. The first three parts of SANS 204 have been published, while the fourth part of the standard is still at a project stage.
“The key point is that, although SANS 204 will at first be voluntary, the DME and Dti will make it mandatory, as soon as is practical. While intended for mandatory application in new buildings, SANS 204 can also be used for voluntary energy efficient retrofits of existing buildings, as the owners strive to reduce their electricity and energy accounts. Each part of SANS 204 covers a different aspect. A short summary of each part follows.
“SANS 204-1: This gives the general requirements for energy efficiency. According to the approach used in the revised South African Building Regulations and the new building code (SANS 10400 series), which should be published early in 2009, performance parameters are outlined first. These are then followed by the route to demonstrate compliance, either by rational design or deemed-to-satisfy rules.
“This first part therefore sets out the general requirements for achieving energy efficiency in all types of buildings as performance parameters, and will eventually form part of the National Building Regulations. Parts 2 and 3, which deal with naturally ventilated buildings and artificially ventilated buildings, respectively, will eventually become part of the SANS 10400 National Building Code.
“Part 1 is largely based on two tables, namely:
Table 3 (Maximum energy demand per building classification for each climatic zone), and
Table 4 (Maximum annual consumption per building classification for each climatic zone).
“Annex B contains an example of a compliance certificate, which, in future, will have to be completed by the responsible person (i.e. developer or owner), and submitted together with the building plans to the local authority for approval.
“This certificate also requires an energy audit to be conducted a year later, to prove compliance and measure the actual energy saved. This process is intended to facilitate any revisions of the standards that may become necessary. The certificate, therefore, should not be seen as a “policeman”, but rather an opportunity for continued improvement.
“SANS 204-2 and SANS 204-3: As already mentioned, Part 2 covers naturally ventilated buildings (with natural environmental control), while Part 3 is for artificially ventilated buildings with artificial environmental control). A few words first about the difference between the two, as this is not quite as straightforward as it seems.
“Part 3 is for buildings with a central HVAC system (that is, humidity, ventilation and air conditioning). A building without air conditioning is covered by Part 2. However, a building containing free-standing heating or cooling (in other words, not centralised) systems is still included under Part 2. Even a converted house used as an office, with a “window rattler” in each room, will still be covered by Part 2.
"While nominally separate parts, SANS 204-2 and SANS 204-3 both contain many common elements, and are therefore described together. Both are deemed-to-satisfy rules.
“Wherever possible, passive building design (where the need for energy to heat or cool the building is minimised), is encouraged. The standard follows the same order as when an actual building is constructed, i.e. first design, and then construction. The key sections are:
site and siting (orientation and shading – to face north and use shading)
building design (foundation, floor, walls, fenestration (windows), roof, and ceiling)
building sealing (envelope, air infiltration, and leakage), and
services (lighting and power, hot water services, and appliances).
“Wherever possible, the efficient use of renewable energy (such as solar water heating, solar architecture, and energy efficient appliances) is stipulated.
“In effect, the use of renewable energy is “free”, as this is not counted in the actual energy consumption targets. For example, if the target set for the building is 200 kW hr/m2, and 100 kW hr/m2 can be generated by renewables, then the owner still has 200 kWhr/m2 to use.
“To summarise: we will have to start now to improve our buildings’ energy efficiency for the future, The effect of this standard will be increasingly seen in future, as the proportion of energy-efficient buildings increases” Lisa concluded.
Source - Greenbuilding South Africa