Good Lighting and Ventilation is Vital for Healthy Living-Part O

A beautifully lit, airy bathroom.

In terms of the National Building Regulations Part O, 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 SANS 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.



  81 Responses to “Lighting and Ventilation”

Comments (81)
  1. Useful website I am an environmental health student

  2. Hi
    We’re building a new house and have asked the architecht to have a guest bathroom in the “middle” of the house. It’s not along side any exterior wall. We wanted and extractor for artificial ventilation and a skylight for natural light. He said that it would be impossible. Is it against the law to have a bathroom like this?

    • The issue here might not be because of the ventilation or lighting, which are essential as well, but more the waste pipes and air vent that has to be built into the system.

  3. Hello Penny

    I need to install a window unit extrator fan in a restroom, on the 8th floor of an office block.
    I have been told that I need to change the existing 4mm glass to safety glass. Is this correct?


    • I have to admit I have no idea, though it would usually depend on the size/extent of the glass. Don’t rely on your glazing contractor – ask your local authority for clarification.

  4. Is it a requirement to have natural light and ventilation in office building. There may be airconditioners, but in the event of a power failure, there is no other source of light or ventilation.

    Must all offices have windows, and should these be openable?

    • Interesting question. The NBR don’t cover this. There may be other legislation that does. I’m not sure. Certainly there are shops that have to shut down in the event of a power failure or load-shedding. They simply shut their doors.

  5. I am thrilled to have found this site but do not know whether I at the right place. In Jan 2010 I accepted a quotation for the electricity installation in a new dwelling. I have since come to the realization that it is totally wrong. When I try to switch off my geyser the plugs in the living room go off and not the geyser. Have still not been able to figure out which switch is for the geyser. I would like to know if I have recourse re this problem. The municipal plans were approved and the final inspection done. According to the quotation this electrician is registered with the SA Electrical Contractors Board and has given his registration number on the quote. Please if anyone could help me with information I would be grateful. Middelburg Mpumulanga

    • You must contact the ECA (Electrical Contractors Association) and report the situation to them and ask them to send an inspector to examine the installation.

  6. Is it necessary to have a window in a bedroom, or is it ok to have artificial lighting

    • If there is no natural lighting then artificial lighting needs to meet NBR standards – AND you will need adequate ventilation. This should be indicated on the plans.

  7. Hi Penny,

    A client of mine is completing a E2 type public building but they cannot get both Electrical and Main Water connections from the local municipality, they are contractors, is it possible for them to an Occupation Certificate for the building ? They need to hand over the project / get it to practical completion stage.

    Your assistance in this regard is much appreciated.


    • There is no way you can legally get an occupation certificate for a building without mains water. I don’t believe you have to have electricity. For instance the owner may only require gas or alternative types of energy. But water is a must. If I was to hazard a guess I would say the only reason they can’t get the connections is either because the owner of the property has not authorized the application and/or the due payments have not been made. I may be wrong in my assumptions though.

  8. I am currently renovating and my house was originally built in the 1960’s. There are air bricks everywhere including internal walls. I notice a trend in modern building not to have air bricks. Please advise as i have ecluded these from all my major renovations and now feel i might have made a huge mistake!

    Thank you

    • Robert I have looked through the old regs (1977 as amended up to 1990) as well as the current regs – Part K, Walls, and can’t find any references to air bricks. If you are doing major renovations you should have had plans drawn up by a competent person who should have known if and where they should be incorporated in terms of good building practice.
      Generally air bricks are often built in above window openings for ventilation and below suspended timber floors. Some local authorities do require them – but this would be specified in their bylaws.

      • I moved into an apartment 15 days ago. It’s a modern building less than 10 years old. There are no air bricks in any of the rooms. The bathroom is no more than 9 square metres. It’s winter and we keep the bathroom window closed when bathing or in shower. Mould has already started growing. Is there any regulation or by-laws regarding proper ventilation in bathrooms?

        • The reason I’m asking is that the agent has built into the lease contract that we are responsible for any moulds or mildew that may build up in the bathroom. If ventilation in the bathroom is not according to regulation, that already puts us at a disadvantage.

          • You can ask a few of the other tenants if they have the same problem and if yes then contact your local council and point out all the units that have the same problem and can they please put the landlord to terms to rectify the “fault”.

        • Yes there are regulations regarding ventilation in rooms such as bathrooms. The SABS 10400-Part O says that a room must have a opening such as a glazed window that is no less than 5% of the floor area of the room or 0,1 sqm whichever is the greater. Artificial ventilation is an “or” if there is no window opening. So it sounds as if the regulations are being followed.

  9. We bought our property in 2010, we have made no alteration but now want to sell to be told we don’t have an occupational cert for a braai area that was enclosed pre 2002.
    It has effectively left the kitchen with a door and window leading I to a room 8x4m2. We have been told we need an extractor fan to meet building regulation. The kitchen is about 2.5 x 3.9m2. What size extractor would we need?
    Thank you

    • Jannine, you don’t need an occupational certificate for a braai area unless it is enclosed and under a roof. You would only need an extractor fan if there was insufficient natural ventilation. It is not a standard requirement.

  10. Hi I live in a 1st floor flat and the wall of my bedroom is the boundary of the house next door which is also a double story.It has a room at the back of this house which is only about 4 metres from my bedroom window.New owners have just moved in and have installed an air conditioner at the back of the wall and it runs off and on all night giving me very little sleep,it is noisy.I went to see the neighbour and he said that is his bedroom.Can I ask him to put a cover around to quiten it and what are the building regulations regarding air conditioners and noise. Thank you,patrick.

    • Patrick the NBR does not cover air conditioners and noise! However this might be construed as public nuisance. You could certainly ask him to do something to quieten the noise – that would be a reasonable request. If he refuses, then you would probably have to take the matter to a lawyer to force him to take action.

  11. Dear sirs,
    I am hoping you can assist me.
    I am a supplier of lighting and electrical items.
    I am not an electrician am I allowed to change existing light fittings or even replace burnt out ballasts / transformers.

    Eagerly awaiting your reply

    • Craig I don’t think so. You just can’t rewire a system. You can definitely change the existing light fittings. BUT you do need to know what you are doing – and isolate the area before you work.

  12. Hi i am a civil engineering student n my brother asked me to design a ground plan for i qualified to do so?

    • Nicholas you aren’t qualified… You need to be both qualified and registered with one of the associations that caters for people who have qualified in terms of the Council for the Built Environment Act, 2000 – in your case engineering. However in your case you may well have the knowledge and depending what it is for, you might be able to get a qualified, registered engineer to sign of the plan for a small fee.

  13. Great informative article. Our apartment has a non windowed bathroom, and has literally the smallest extractor fan on the market fitted: it does not remove odour and definitely not moisture/steam. It is connected to a communal exhaust pipe shared with 3 other units, and in my eyes that is the problem, almost as if there is not enough power to suck it out. The walls after just two short showers are so damp that droplets form EVERYWHERE, and it drips from the doorway onto the floor! Does this sound like it conforms to the regulation? I want to take on the builder 🙂

    • Don, no it doesn’t sound as if it conforms. There are two issues here – one that relates to plumbing and the other being the standard of the extractor fan itself. The latter needs to be SABS approved for function.
      Bathrooms must have sufficient air supply as well: “Air supply required per person with required minimum air changes per hour”
      Bathrooms and shower rooms & Rooms containing a toilet pan or urinal both require 10 air changes per hour; and 25,0 litres of air per person.
      I would do two things. One, consult with a reputable plumber who is both qualified and registered, and ask for a written report. Two, contact the SABS with details of the fan and ask their advice in terms of compliance. You need to ascertain 100% that the builder (developer) has not complied.

      • Thank you Penny, I will do just that. I will take the cover off the front to get the model type so I can research it’s performance. Reference air supply, does the extractor exhaust pipe qualify as an air supply as well? Because that is all that is in the bathroom, no ventilating bricks or grids, just the small extractor, which doesn’t extract 😉

        • Don, I really do think you need to ask a professional to look at the setup. But I don’t see how an exhaust pipe could qualify as “air supply” since it is extracting air. Sounds like the only air supply will be through the door.

          • Agreed! I will bring in a qualified plumber to assess. Thanks for your help.

          • Hi Don
            Hope you have come right.
            The exhaust duct or pipe forms part of the overall airflow system. If it is restricted by obstruction or if the diameter is less than the manufacturers required specs, airflow is also restricted and the extractor will not deliver its specified capacities.
            At the same time, as Penny’s comments confirms, air intake is equally important. An installation of a fan delivering 500 cubic meters of extraction per hour cannot be effective if the airflow inlet only allows for only 100 cubes per hour.
            Many installers fail to bring this aspect into the equation!
            If your bathroom door is closed during shower sessions, the only airflow intake would be from the opening slit below the door and from the airbrick openings if you have an airbrick in your bathroom. If there is no gap under your door, there will be no airflow through your extractor fan!
            Also, the extractor system requires some form of minimal maintenance and cleaning on a bi-annual basis. With exposure to steam and dust particles the inlet grill as well as the exhaust ducting leading to your communal exhaust pipe may become clogged, which may negatively affect airflow.

            The measurement of airflow as well as the inlet specifications of your specific fan should be easily obtainable from the manufacturer.

            I hope this info may be of some assistance!
            Kind regards

            Reinhardt Badenhorst

  14. Hi,

    I want to design apartments that do not have access to natural light on one side of a building.

    Will artificial Light suffice or will I run foul of regulations

    • George, In terms of the law, only a competent person can draw plans. If you are a competent person, you should know the answer to this question!
      The key SANS will be those that relate to lighting and ventilation as well as fenestration. You can download the draft copy of Part X & XA from our downloads page.

  15. Hi Guy, could you please advise if there is any regulations regarding how many windows/light is allowed in bedrooms? I was informed one is not allowed to have more that 15 %. For me, it does not make any sense.

    • The only relevant reference to bedroom windows in Part O of the regulations states that: “Any habitable room in any dwelling house or dwelling unit, or any bedroom in any building used for residential or institutional occupancy shall, notwithstanding the provision of artificial lighting, be provided with at least one opening for natural light in accordance with subregulation O1(1).” 01(1) states that lighting and ventilation must ensure rooms may be used, “without detriment to health or safety or causing any nuisance, for the purpose for which it is designed”.
      In terms of windows in general, the Standard states that, “The total area of an opening, a door or an openable glazed window that complies with the requirements of [an opening or door in an external wall], or (b) [an openable glazed window in an external wall or in a suitable position in the roof shall be not less than 5 % of the floor area of the room”. i.e. these are minimum requirements – this Part doesn’t give maximum requirements.
      The new Part X – Environmental sustainability – and XA – Energy usage in buildings – deals with fenestration [defined as any glazed opening in a building envelope, including windows, doors and skylights].
      This Part has a section on fenestration that states:
      1. Buildings with up to 15 % fenestration area to nett floor area per storey comply with the minimum energy performance requirements.
      2. Buildings with a fenestration area to nett floor area per storey that exceeds 15 % shall comply with the requirements for fenestration in accordance with SANS 204.
      So it doesn’t say you CAN’T have more than 15% – just that if you do you must do it correctly in accordance with the Standard (SANS 204).
      SANS 204 specifies the design requirements for energy efficiency in buildings and of services in buildings with natural environmental control and artificial ventilation or air conditioning systems. The current edition was published in the second half of 2011 and is available from the SABS at a cost of R297.
      There are some guidelines HERE.

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