Alterations and Additions to Your Home
There are so many changes that have been made to the National Building Regulations in recent years that homeowners may be forgiven for wondering what is and what is not allowed in terms of altering and making home additions.
Some of the greatest concerns relate to the new energy laws and regulations in the form of SANS 10400X (2011) and SANS 204 (2011). For instance, many homeowners wanting to make home additions and extend their home or alter certain aspects of it are concerned that these home additions will become much more substantial because they have to worry about fenestration issues.
Fenestration in Homes
Fenestration, of course means any glazed opening in the “building envelope”, including doors, windows and skylights and can be seen as home additions.
The fenestration area as a whole is that part of the house that includes glazing and framing elements (in other words door and window frames as well as the glass) that are fixed or movable (can be opened), and opaque, translucent or transparent (which broadly describes the different types of glass or glazing possibilities).
Issues relating to fenestration include solar heat gain coefficient (SHGC) which is the ratio of the heat gain that enters the space through the fenestration area to the incident (or amount of) solar radiation (which is reflected and direct). Specifically:
- Buildings with up to 15% fenestration area to net floor area on each floor (or storey) must comply with the minimum energy performance requirements specified in the regulations.
- Buildings with a fenestration area to net floor area on each floor (or storey) that exceeds 15% must comply with the requirements for fenestration in accordance with SANS 204.
- All fenestration air infiltration must comply with SANS 613: Fenestration products – Mechanical performance criteria.
While it’s certainly in your own interests to do what you can to ensure that your home complies with the regulations as they apply to fenestration, it is not normally mandatory when you are doing alterations and home additions to existing buildings. In the case of home additions, you will normally need to comply.
Alterations and Home Additions to Existing Buildings
While the National Building Regulations and deemed-to-satify South African National Standards – specifically SANS 10400 – do not deal with alterations and additions as such, there is a section within Part A, General Principles and Requirements that is explicit in terms of what is expected of you as a homeowner.
This section (B.11) states that while in general the National Building Regulations “are not retroactive in application, a problem might arise when alterations or additions are carried out on buildings that have been erected in compliance with earlier building by-laws.
New vs Old Regulations
“In the case of an addition it might be possible to treat the new portion as an entirely separate part which can be designed to comply with the National Building Regulations without having any effect on the original portion of the building.” This clearly refers to the regulations that have been introduced progressively since the National Building Regulations and Building Standards Act 103 of 1977 was dramatically amended in 2008.
“In the case of an alteration, this will seldom be so and it therefore becomes necessary to ask to what extent that part of the building which is not to be altered should comply with the National Building Regulations. This might be particularly pertinent in the application of fire regulations where escape route requirements, for instance, tend to be more stringent.”
While the regulations don’t refer to energy issues here, they certainly are relevant.
Health & Safety
“It is obvious that a pragmatic and essentially practical approach is necessary. In terms of the functional regulations every attempt shall be made to ensure the safety and health of the occupants of the building, but this should be within the context of what might be practical and economically sound in an old building.”
Cost Factor
Cost is also a vital factor. If you as a homeowner are going to be forced to make extensive changes just because you are adding on a room, or fitting a sliding door where there are currently windows, it’s going to put you off making the changes.
“If an owner or entrepreneur cannot alter a building to suit his purpose at a cost which will enable him to have a reasonable economic return, he will probably not alter the building at all. This could lead to the perpetuation of a situation which might be dangerous but one which is in compliance with old by-laws and is thus perfectly legal. Such a situation could often be considerably improved by making certain changes that are practical and economically sound even though they would not provide the same standard as would be expected in a new building.
“Both the owner and the local authority will have to consider what they are trying to achieve with the Regulations and the answer should be tempered by the knowledge of what is reasonable and practical to require of an existing building.”
Which is why we always advise people to consult with their local authority. If decisions are unreasonable there are recourses for you to take.

