SANS 10400X & XA Archives » Building Regulations South Africa
May 272013
 

What the National Building Regulations say about Alterations and Additions to Existing Buildings

Additions366 Alterations & Additions

If you build onto an existing home you will need to submit plans and comply with the “new” building regulations, including Part XA which deals with energy usage.

In general, the National Building Regulations are not retroactive in their application. This means that if you are adding to or altering a building, you won’t have to ensure that the entire building complies with new regulations that have been imposed since the building was originally erected.

This will be of particular interest to people who are concerned about the implications of the new energy efficiency legislations and regulations

But if you need plans for any additions or alterations, then you will need to ensure that the new section of the building complies.

Part A of SANS 10400, General Principles and Requirements, deals with alterations and additions.

This part of the National Building Regulations states that where an application is made to make an alteration or addition to any building that was approved before this version of the Building Regulations and Standards Act (i.e. prior to 2008):

  • The  alteration must comply with the requirements of the Act, but “consequent changes to any other part of the building which would be necessary in order to make such other part comply with the requirements of the Act shall not be required unless in the opinion of the local authority such consequent changes are necessary to ensure the health or safety of persons using the building in the altered form”
  • The addition must comply with the requirements of the Act, “but no changes to the original building shall be required unless the addition :
    1. will affect the structural strength or stability of the original building;
    2. will render any existing escape route from the original building less effective; or
    3. will affect the health of persons using the original building.

Problems May Occur When Adding to Older Buildings

In addition to the above, the law-makers are aware that problems might arise when alterations or additions are carried out on buildings that were erected in compliance with earlier building by-laws.

In the case of such an addition the local authority (which is of course the body that will approve any plans that might be required for such an addition or alteration) might decide to treat the new portion as an entirely separate part. If this happens, then the alterations will have to be designed to comply with the National Building Regulations “without having any effect on the original portion of the building”.

This is not likely to happen often with alterations, though the local authority will decide “to what extent that part of the building which is not to be altered should comply with the National Building Regulations”. Generally they will be more stringent when it comes to the application of fire regulations (Part T, Fire protection), and particularly when it comes to escape route requirements. Since this doesn’t affect “dwelling houses”, it is unlikely to have any effect on residential buildings.

The regulations state: “It is obvious that a pragmatic and essentially practical approach is necessary.”

Their primary concern is the health and safety of those people using the building. But they advise local authorities that any decisions “should be within the context of what might be practical and economically sound in an old building. 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.”

 

 

May 152013
 

Environmental Sustainability &
Energy Usage in Buildings

w house 25 800x510crp Energy Usage & Sustainability (SANS 10400X & XA)

Glazing and lighting are two vital factors when it comes to energy usage.

In 2011, in an endeavour to make our buildings more sustainable, and to decrease energy usage in South Africa, a new part was added to SANS 10400, The application of the National Building Regulations. Part X deals with environmental sustainability, and Part XA deals with energy usage in buildings.

In many ways these new regulations have turned the building industry upside down, but not in a bad way. However for the average man-in-the-street it has become a puzzle of note. Every week we get people writing into this web site asking for advice and information about the “new energy laws” and how they affect their building and renovations.

On the down side, it seems that new regulations have opened up a can of worms that has less-than-knowledgable people (and some scamsters) flippantly quoting “the new green laws” in an effort to force people to spend more money than they need to on energy-efficient materials, appliances and the like. While there is no doubt that we need to “go green” and get our act together (pun intended) in terms of energy efficient building, it is also important to know the difference between what we should do, and what we must do to comply with the National Building Regulations and other national standards.

What the National Building Regulations and Building Standards Act Says

While the Act was originally passed in 1977 (officially it’s Act 103 of 1977), a number of amendments have been added to it over time. In 2011, Rob Davies, the Minister of Trade and Industry added the sections that relate to environmental sustainability and to energy usage in buildings.

The motivation for this amendment is to reduce greenhouse gases caused by buildings and extensions to buildings. These relate to a number of specific occupancies that are defined in Part A of SANS 10400, namely:

  • A1 - Entertainment and public assembly Occupancy where persons gather to eat, drink, dance or participate in other recreation.
  • A2 - Theatrical and indoor sport Occupancy where persons gather for the viewing of theatrical, operatic, orchestral, choral, cinematographical or sport performances.
  • A3 - Places of instruction Occupancy where school children, students or other persons assemble for the purpose of tuition or learning.
  • A4 - Worship  Occupancy where persons assemble for the purpose of worshipping.
  • C1 - Exhibition hall Occupancy where goods are displayed primarily for viewing by the public.
  • C2 - Museum Occupancy comprising a museum, art gallery or library.
  • E1 - Place of detention Occupancy where people are detained for punitive or corrective reasons or because of their mental condition.
  • E2 - Hospital Occupancy where people are cared for or treated because of physical or mental disabilities and where they are generally bedridden.
  • E4 - Health care Occupancy which is a common place of long term or transient living for a number of unrelated persons consisting of a single unit on its own site who, due to varying degrees of incapacity, are provided with personal care services or are undergoing medical treatment.
  • F1 - Large shop Occupancy where merchandise is displayed and offered for sale to the public and the floor area exceeds 250 m2.
  • F2 - Small shop Occupancy where merchandise is displayed and offered for sale to the public and the floor area does not exceed 250 m2.
  • F3 - Wholesalers’ store Occupancy where goods are displayed and stored and where only a limited selected group of persons is present at any one time.
  • G1 - Offices Occupancy comprising offices, banks, consulting rooms and other similar usage.
  • H1 - Hotel Occupancy where persons rent furnished rooms, not being dwelling units.
  • H2 - Dormitory Occupancy where groups of people are accommodated in one room.
  • H3 - Domestic residence Occupancy consisting of two or more dwelling units on a single site.
  • H4 - Dwelling house Occupancy consisting of a dwelling unit on its own site, including a garage and other domestic outbuildings, if any.
  • H5 - Hospitality Occupancy where unrelated persons rent furnished rooms on a transient basis within a dwelling house or domestic residence with sleeping accommodation for not more than 16 persons within a dwelling unit.

But they specifically EXCLUDE garage and storage areas contained within these specified occupancies, as well as a number of other buildings that are used for commercial, industrial and buildings used exclusively for a variety of storage uses.

The law (because this is part of the Act – not SANS 10400) states that these “occupancies” (types of buildings) must be:

  • capable of using energy efficiently while fulfilling user-needs in relation to various things including thermal comfort, lighting and hot water; OR
  • have a “building envelope and services” that facilitate the efficient use of energy that is appropriate to the function and use of the building as well as its geographical location and its internal environment.

So it is not a one solution fits all situation. For instance, what works for a house in Durban may not make the same structure energy efficient in Cape Town! In addition, the legislation excludes the “equipment and plant” required for conducting business – if the building is used for business.

Hot Water Heating Requirements

XA2 requires that at least a half – “50% (volume fraction) of the annual average hot water heating requirement shall be provided by means other than electrical resistance heating including but not limited to solar heating, heat pumps, heat recovery from other systems or processes and renewable combustible fuel”.

So you can use a conventional geyser IF you meet the 50% requirement. And if you are renovating, you certainly don’t have to toss all your existing water equipment and go solar – even though there is absolutely no doubt that it’s the way to go.

What is Required

The orientation, shading, services and building envelope must be designed according to SANS 10400 Part XA. Alternatively the rational design of the building must be done by a competent person who “demonstrates that the energy usage of such building is equivalent to or better than that which would have been achieved by compliance with the requirements of SANS XA, or has a theoretical energy usage performance, determined using certified thermal calculation software, less than or equal to that of a reference building in accordance with SANS 10400 Part XA”.

If you’re looking to change jobs, becoming a person competent to specify these requirements is one way to go! It is something that is not easy for someone who hasn’t got the relevant training to get their head around.

What 10400 XA Says

As with all national standards, 10400 XA has a number of definitions, some of which are in the glossary that is part of the Act.

A few of the important definitions that relate to this particular part of the standard are:

  • Building envelope Elements of a building that separate a habitable room from the exterior of a building or a garage or storage area 
  • Competent person Person who is qualified by virtue of his education, training, experience and contextual knowledge to make a determination regarding the performance of a building or part thereof in relation to a functional regulation or to undertake such duties as may be assigned to him in terms of the National Building Regulations
  • Fenestration Any glazed opening in a building envelope, including windows, doors and skylights
  • Fenestration area Area that includes glazing and framing elements that are fixed or movable, and opaque, translucent or transparent

Requirements of 10400 XA

The requirements of this new national standard cover:

  1. Hot water supply
  2. Energy usage and building envelope
  3. Design assumptions
  4. Building envelope requirements

The standard also defines the different climatic zones of South Africa.Climate zones XA1 Energy Usage & Sustainability (SANS 10400X & XA)

To be a little more specific, the main centres for each zone are:

  • Zone 1 – Johannesburg and Bloemfontein
  • Zone 2 – Pretoria and Polokwane
  • Zone 3 – Makhado and Nelspruit
  • Zone 4 – Cape Town and Port Elizabeth
  • Zone 5 – Durban, Richards Bay and East London
  • Zone 6 – Kimberley and Upington

Building Envelope Requirements

This is probably the most vital part of the new regulation, and it addresses orientation, floors, external walls, fenestration, and roof assemblies – but not in a lot of detail.

Floors

If any type of underfloor heating system is used in a home, this must be insulated under the concrete slab with insulation that has a minimum R-value of at least 1,0. The R-value is the thermal resistance (square metre K/W) of a component. According to the Standard, it is “the inverse of the time rate of heat flow through a body from one of its bounding surfaces to the other surface for a unit temperature difference between the two surfaces, under steady state conditions, per unit area”.

Roof Assemblies

Any roof assembly must achieve a minimum R-value for the direction of heat flow. This is specified in several tables in the regulations.

 Minimum total R-values of roof assembliesPart XA Min total R values of roof assemblies Energy Usage & Sustainability (SANS 10400X & XA)

Roofs with metal sheeting affixed to purlins, rafters or battens made of metal are required to have a thermal break that consists of a material with an R-value that is not less than 0,2, and which is installed between the sheeting and the support. In addition, roofing assemblies that utilize metal sheeting must achieve a minimum total R-value that meets the requirements shown in the table above. Insulation must also be installed with an R-value that meets the specified in the table below.

Metal sheeting roof assembliesPart XA Metal sheeting roof assemblies Energy Usage & Sustainability (SANS 10400X & XA)

Clay tiles used for roofing must achieve a minimum R-value as in the first table above. Insulation should be in accordance with the specifications shown below.

Part XA Clay tile roof assemblies Energy Usage & Sustainability (SANS 10400X & XA)

The other standard that you need to know about is
SANS 204 (2011): Energy efficiency in buildings.  

 

Nov 152011
 

Chimneys, Flues, Hearths and Fireplaces
Used for Space Heating

FireplaceBR1 Space Heating

A freestanding fireplace with a flue that goes through ceiling

Anyone searching through the National Building Regulations for information about chimneys and flues, hearths and fireplaces, might go straight to the part that deals with Fire Protection. The next step would probably to look through the part that deals with Walls – after all chimneys are often built with bricks and mortar and often extend from a wall. Or Roofs might seem to be a good place to look.

But no, you are not going to find the information you are looking for in any of these three sections of the NBR. The information you need is in Part V of the Act. This section is very short, and deals only with the design, construction and installation of fireplaces and hearths that have chimneys and/or flues.

 

 

 

 

 

 

 

The legislation states:

“(1)  Any system of space heating in any building shall be so designed, constructed and installed as to operate safely and any flue, flue pipe or chimney used in such system shall be so designed as to safely remove any smoke or noxious gases produced by such system.

“(2)  The requirements of sub-regulation (1) shall be deemed to be satisfied where the design and construction of any flue pipe, chimney, hearth or fireplace complies with SANS 10400-V.” That’s it.

SANS 10400-V: Space Heating

As with all the Standards that make up SANS 10400, if you ensure that your installations comply with the SANS it will be “deemed to satisfy” the law. But other Standards are often cross-referenced. This Part of SANS 10400 makes reference to:

  • SANS 10177-5, Fire testing of materials, components and elements used in buildings –– Part 5: Non- combustibility at 750 °C of building materials.
  • SANS 10400-A, The application of the National Building Regulations –– Part A: General principles and requirements.
  • SANS 10400-B, The application of the National Building Regulations –– Part B: Structural design.

Like all the published SANS, it has a list of useful definitions, some of which you will find in our Glossary of Terms.

Examples include:

  • chimney That part of a building which forms part of a flue, but does not include a flue pipe
  • flue Passage which conveys the discharge of a heat-generating appliance to the external air
  • flue pipe Pipe forming a flue, but does not include a pipe built as a lining into a chimney

Hearth and fireplace are not defined!

Chimneys

Chimneys must be designed and erected from materials that are non-combustible – which of course stands to reason. It is also important that they don’t become a fire hazard, particularly to those materials adjacent to the chimney structure. Further, chimneys should not reinstalled in shafts or ducts that might be affected by heat.

Timber is one of the combustible materials that we commonly use in our homes, and the regulation states that elements including joists for timber floors, trimmers or roof trusses may not be built within 200 mm of the inside of any chimney.

There are additional regs that relate to dimensions, for instance where the walls of a brick or block chimney are less than 190 mm-thick, it must be lined with a flue lining that is made of a material that will withstand the action of any flue gases and won’t crack or soften. The flue lining must also extend throughout the full height of the chimney.

There are also regulations that relate to the height of the outlet – this has not changed since the regulations were published previously in 1990 (and of course you can download these free). Below you can see the chimney positions.

Part V opening or adjacent structure Space Heating

Opening or adjacent structure

Part V roff pitch 10 deg or more  Space Heating

Position when the roof pitch is 10 degrees or more

Part V Roof pitch less than 10 deg Space Heating

Roof pitch less than 10º

Flue Pipes

This is all largely common sense. Flue pipes may not be designed or installed if they are going to become a fire hazard to adjacent material. They may also not be connected to shafts or ducts that form part of any ventilation system. And they may not be installed in shafts or ducts that are likely to be adversely affected by heat.

Hearths and Fireplaces

Any fireplace that is used for burning “solid fuel” MUST have a hearth that is make of a non-combustible material that is sufficiently thick. It must extend no less than 500 mm in front of the grate or fire basket and not less than 300 mm beyond each side of the grate or fire basket.

Timber floor joists and trimmers – or any other combustible material – may be built into a hearth.

 

 

Nov 152011
 

Good Lighting and Ventilation is Vital for Healthy Living

Bathroom173 Lighting and Ventilation

A beautifully lit, airy bathroom.


In terms of the National Building Regulations, all habitable rooms, including bathrooms, showers and toilets (and interestingly enough garages!) must have some form of lighting and ventilation that will enable people to use these rooms safely. The most important aspect is that it shouldn’t be detrimental to the health of those using the room for the purpose for which it was designed.

If bathrooms are cold and perpetually damp, mould will start to form, and this can make people extremely ill. It will also make the room uncomfortable.

Lighting and Ventilation Requirements

Changes to Part O of the NBR (when the legislation was updated a few years ago) include a welcome move from WC (short for water closet – and a very Victorian term) to “toilet”.

There are also quite substantial changes to this section of the regulations. While the lighting and ventilation regulations are generally “deemed to satisfy” if they quite simply meet the requirements of SANA 10400-O, the NBR states that if there is not sufficient natural light from windows in habitable rooms, as well as corridors, lobbies and on staircases, artificial lighting MUST be provided.

Reasons for inadequate lighting might be due to:

  • the size or shape of the room or space, or
  • the use of thick, patterned or opaque glass for windows, which prevents natural light from illuminating the room.

Similarly, if there is insufficient ventilation, artificial ventilation MUST be installed.

Reasons for inadequate ventilation include:

  • high temperatures which could be dangerous to either the safety or health of those using the room,
  • dust, gases, vapour, “volatile matter” or “hazardous biological agents” that might be dangerous to health or safety, or
  • the purpose for which the room is used may make natural ventilation unsuitable or inadequate.

Compliance Required for Lighting

While the Act states that, “Any habitable room in any dwelling house or dwelling unit, or any bedroom in any building used for residential or institutional occupancy” MUST have at least one opening for natural light – even if there is artificial lighting.

Compliance Required for Ventilation

It doesn’t matter where in South Africa you live, any artificial ventilation system MUST be authorized by your local authority (council or municipality, or City) according to their own specific policies and opinions.

This applies to everything other than regular air conditioners and other appliances installed essentially for comfort.

Further, the “rational design” of any artificial ventilation system must be performed or supervised by an “approved competent person”.

Compliance with Fire Requirements

In addition to the general requirements in this section of the Act, all lighting and ventilation must also comply with Part T of the NBR, a very lengthy section that deals with fire protection.

SANS 10400-O

Part O of the “new” SANS were published in January 2011 after fairly substantial updating by the SABS in collaboration with Agrément South Africa, the South African Institution of Civil Engineering (SAICE), and the South African Refrigeration and Air Conditioning Contractors Association (SARACCA).

Requirements specified in the SANS include:

  • general requirements,
  • requirements relating specifically to lighting,
  • requirements relating specifically to ventilation, and
  • requirements for designated smoking areas and smoking rooms.

Natural Lighting

The SANS specify zones of space for natural lighting which are guidelines that should be adhered to. These relate not only to the measurement of openings, but also to the angles of openings, and they specify how various obstructions affect zones of space.

Natural Ventilation

Generally, natural ventilation should be organized so that doors and windows relate to one another in such a way that the room will be effectively ventilated, and it should be at least five percent of the floor area of the room (or at least 0,2 square metres if the room is very small).

But anyone designing a home also needs to take into account the fact that in cold, wet or windy weather, doors and windows will commonly remain closed. This will minimize natural ventilation.

In holiday homes, or buildings that people only use occasionally, doors and windows will usually remain closed for long periods of time. Where weather conditions are very hot and humid, the interior of the building may become damp and mouldy. Airbricks built into the structure help; as do roof vents that provide permanent ventilation, even when doors and windows are closed.

Artificial Ventilation

The simplest and most common form of artificial ventilation is found in kitchens and bathrooms, in the form of extractor fans.

Extraction in kitchens (from stoves and hobs) not only removes heat or steam and other vapour, but it also has the effect of removing grease that is in suspension, by filtration. Because the greasy air being removed is hot, the regulations state that extraction units must be manufactured from non-combustible material.

In bathrooms and toilets, extractor fans remove humid air and filter bad smells.

Air Requirements in Homes and Other Buildings

SANS 10400-O contains a useful table that shows the minimum requirements for air, per person using the room. Again it is the health and safety of inhabitants that is vital. Where rooms are used for smoking, a considerably higher supply of healthy air is required.