Nov 152011
 

Glazing and the Glass You Use for It-Part N

All forms of glazing need to comply with the relevant SANS.

Part N is the section on glazing in the National Building Regulations & Building Standards Act and is short and reasonably sweet.

Essentially you need to be sure that any material used for glazing in buildings is secure and durable and that it is fixed so that it:

  • safely sustains wind actions that one would normally expect wherever you live in South Africa (but not necessarily major hurricanes or tornadoes that might be experienced in other parts of the world),
  • does not allow water to penetrate the interior of the building, and
  • is obvious to anyone who approaches it (if it isn’t, people could walk right into the glass and be injured, particularly if it is completely transparent and not made of “safety glass”).

Of course it isn’t only glass that we use for glazing. There are also a number of plastic and polycarbonate materials, as well as organically-coated glass, which can be used.

When it comes to choosing the best type of glazing for the job, the essential aspect is to make sure that if someone (or an animal) does impact the glazing – or collide with it, they won’t be seriously hurt. Factors to take into account include:

  • the position of the glazing,
  • the number of people who are likely to be able to access the glazed door or window, and
  • the probably behaviour patterns of anyone (or anything) that is likely to get close to the glazed area.

And ultimately, as long as the glazing material is selected, fixed and marked in accordance with SABS 10400-N, all should be well and legal… and safe for all concerned.

NBR Changes that Relate to Glazing

The “new” National Building Regulations are a lot more specific in terms of glazing installations than they were previously. Not only is the maximum pane area and glass thickness specified, but so too are the different types of glass. These are:

  • monolithic annealed glass,
  • patterned annealed and wired glass,
  • laminated annealed safety glass,
  • toughened safety glass.

In addition to this, glass must also comply with the relevant SANS, as must the method of fitting the glass or alternative material used for glazing.

Just be aware that whether you are glazing doors, windows, shower cubicles, shop-fronts or anything else, glazing MUST comply with SANS 10400-N as well as other standards that relate to the manufacture of glazing materials.

Construction Standards of Glazing

The SABS also has a strategic policy that relates to glazing in buildings. The reason for this is to standardize glazing in buildings in terms of:

  • terminology (so that we all understand exactly what the regulations mean and relate to),
  • performance requirements,
  • various methods of calculation,
  • design and construction guidelines,
  • the classification and specification of materials (including dimensional properties).

To this end, the SABS has a sub-committee that specifically develops, maintains and co-ordinates standards in the field of glazing materials that are used in buildings. The committee’s responsibility is to:

  • develop national standards,
  • participate in the development of standards (getting votes, comment and so on),
  • develop and review the programme of work,
  • recommend what else needs to be done to ensure that the South African standards stay on track with international standards.

At the end of the day, the safety of users and installers is paramount.

Here is a drawing from the Standard that provides guidance

glazing

Examples of safety glazing requirements for exterior doors and windows.

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Lighting and Ventilation

  80 Responses to “Glazing”

Comments (78) Pingbacks (2)
  1. I have just moved into a rented property and need clarification on
    glazing requirements. All the sliding doors have safety glass, but
    what does concern me is that none of windows, waist level and lower
    have safety glass.

    I have children and this is a double story house.

    Please urgently send me an answer and a reference that I can forward
    to agent or landlord.

    Thanks
    Carol

    • Apologies for the delay in responding to your query Carol; we had a glitch on the site in terms of general “Contact Us” queries. However it is important for you to know that when SANS 10400: Part N Glazing was updated (2012) the requirements for safety glazing were one issue that was addressed – and several amendments were made.
      First of all, all “safety glazing material” must comply with the requirements of SANS 1263-1, and individual panes of safety glazing must be PERMANENTLY marked by the installer so that the markings are visible after installation.
      Safety glazing materials must be used where [and these are amendments to the Standard, so may not have been complied with if the glazing was installed prior to 2012]:
      “1. doors and sidelights form part of any entrance up to 2 100 mm from finished floor level;
      2. a window has a sill height of less than 500 mm from the floor or external ground level;
      3. a window has a sill height of less than 800 mm from the floor or external ground level without any permanent barrier that prevents persons from coming into contact with the glass panel, and is so placed that persons are likely, on normal traffic routes, to move directly towards such window; (NOTE A barrier could be any feature, i.e. a heavy bar across a window, or a flower box placed in front of the window, that will provide a physical or visual barrier between the glass and a person.)
      4. a bath enclosure or shower cubicle is glazed, or where glazing occurs immediately above and within a distance of 1 800 mm horizontally or vertically from a bath or shower;
      5. glazing is used in any wall or balustrade to (or immediately adjacent to) a stairway, ramp, landing, pathway, patio, veranda or balcony;
      6. glazing is used within 1 800 mm of the pitch line of a stairway or the surface of a ramp, landing, pathway, patio, veranda or balcony;
      7. glazing is used in internal partitions, which are within 2 100 mm of floor level.”
      There are a few other requirements, but they won’t apply to your situation.
      The Standard also specifies (amongst other things) the maximum pane size and nominal glass thickness for the different types of glass used for exterior doors and windows: “Dimensions for vertical glass supported by a frame on all sides in external walls in buildings where the height measured from the ground to the top of” the “wall does not exceed 10 m.
      Maximum pane area (nominal glass thickness in brackets)
      Laminated annealed safety glass: 2,9 (6 mm), 4,3 (8 mm), 5,7 (10 mm or 12 mm)
      Toughened safety glass: 1,9 (4 mm), 3,0 (5 mm), 4,5 (6 mm), 8,0 (8 mm, 10 mm or 12 mm)
      I have added a drawing from the Standard that shows very clearly what the safety glazing requirements are for exterior doors and windows.

  2. Please advise on the regulation applicalbe for the type of glazing
    required in cottage pane sliding sash windows.

    • Laurinda I suggest you contact a reputable manufacturer and/or installer. The new Part X:Environmental sustainability & Part XA: Energy usage in buildings deals with fenestration [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”] and cross-references SANS 204: 2011 Energy efficiency in buildings, which deals with different types of glass in relation to the new energy efficiency requirements. It isn’t simply the type of glass you should use, but also the orientation of the building and % of glazing included. Not as simple as it used to be when nobody cared much about energy efficiency issues.

  3. We are finalising plans for a new home and the builder/architect says that we are no by law limited to install max 15% of the floor area as glazing. And if it is more thna this then it must be double glazing.

    So now we are installing tiny little windows in bathrooms so as to have a decent size window in our living room. And have to install roof-lites – to get light in, and additional extractor fans. All these take more electricity and the reason for the less windows it to save electricity by retaining heat in winter!!

    Is this true? Most SA houses have about 30 to 40% floor area in windows?

    Apparently a new European standard that is now law in SA.

    We are building in Fourways, Johannesburg

    • Mel the new section on energy usage Part X and XA deals with this and I haven’t familiarized myself with it at all. There is also a lot of confusion, with companies offering workshops to educate etc. There may also be references to European standards that have to be met. Most of the SANS cross reference both international and local SANS. The draft standard – Energy in Buildings – and a document relating to “fenestration” calculations can both be downloaded HERE.

  4. What does the regulations require as far as glazing of windows in premises that are going to be used as a nursery school

    • The regulations don’t have specific glazing regulations for different types of buildings. But you would definitely need safety glass.

  5. What is the minimum thickness required for domestic glazing to comply with SAGGA standards?I live in Bedfordview.

    • There are various specs for glazing, depending on the square meterage of the glass, its position etc. But the standards you need to comply with are those set down by the SABS. These might be the same as SAGGA’s; I haven’t done a comparison. A good glass company will be able to give you the correct info. The City of Jhb may also have the info readily available.
      My personal opinion is that you should always over specify, since accidents with glazing can cause a good deal of pain and suffering. A few years ago my daughter put her hand through a glass door (by mistake) and the glass sliced an artery. I wouldn’t like anyone to have to live through that kind of ordeal. The property was leased; and the glass was NOT up to spec. In retrospect we should have sued the landlord.

  6. Good day,
    My mom- a pensioner “built” a new house. I think -The glazing is not properly sealed. It always allows rain water in, when the wind blows they make a sound & she paid handsomely for them. We are struggling to get the installer to come through and fix the mess he made.

    Please advise on what steps can be taken for such a case.

    Regards,
    Kim

    • Kim, Your mother should write a letter to the installer – or send an email – putting him to terms. List the complaints and say that if it is not rectified within seven days she will take legal action. Apart from anything else, the “new” Consumer Protection Act affords her substantial rights. Unfortunately though she will have to consult an attorney – if only to get he/she to write a letter of demand to the installer. This often works. Good luck.

  7. I want to install a 2 hour fire rated door for internal office with a georgian wired glass,but I want the receptionist to see who is at the door before she opens, can I install a bigger size more than 100 mm x 300 mm?

  8. Penny,

    We are starting a new venture and need to offer trianing on the legislation governing glass and glass installation (e.g., shower doors must open outwards, patio door glass must be toughened etc…).

    Where can I find this information?

  9. Hi Penny
    Where do I obtain the standards pertaining to steel window frame sizes and specifications?

    Thanks Barry

    • The SABS controls all national standards and specifications. SANS 727:2003 covers windows and doors made from rolled mild steel sections. The standard will be reaffirmed in 2014 – so is valid until then. I am not familiar with the content of this standard, and don’t know whether it lists standard sizes. Andre Grobbelaar’s book Building Construction & Graphic Standards has several pages of drawings with measurements which he has accessed from the trade. You might find this book in a library. It was originally published in 1993, so I cannot vouch how reliable it is. Alternatively contact manufacturers or resellers for information about sizes.

  10. Hi, I am very confused about the double glazing. My architect informed me that according to new building laws I have to have to have double glazing on all doors & windows but I spoke to someone who is building a house who had his plans passed three months ago & he has no double glazing? As double glazing would impact oquite substantially on my budget could you please provide more info in this regard. Thank you for a very informative website.

    • Kim I need to do some research on this one, but I doubt that double glazing is an enforceable design factor because as you say, it impacts on quite dramatically on price. There is probably something in the new Part X of SANS 10400, Environmental Sustainability, which I will be purchasing in the very near future, which RECOMMENDS double glazing. It may also be mentioned in the new Part XA, Energy Usage in Buildings. SANS 204 also provides guidelines and options on how to achieve energy efficiency in buildings, and I am sure discusses the merits of double glazing.
      I found this comment on another website, which indicates that double glazing is an option, certainly not a legal requirement! “As a rule, good design in terms of energy efficiency (as per SANS 204) will prevent the need to add potentially expensive measures, ie double glazing to large south facing windows (where a huge amount of heat loss would occur) or extra shading to west facing windows (which would otherwise cause the house to overheat), in order to meet the minimum requirements.”

  11. Hi,
    I am planning to build a new home and have been told all new houses need to be fitted with double glazed windows etc.

    Thanks
    Charles

    • Charles I doubt it, though there are two completely new section to the building regulations. I will check them out when I get a moment, but for your information they are Part X: Environmental sustainability, and Part XA: Energy usage in buildings. My guess is that there will be certain circumstances that require double glazing, but not ALL new houses.

  12. I would just like to know what the requirements pertaining to balustrading (alluminium) are according to the NBR, and what are the requirements according to the NBR regarding glass balustrades as well.
    Thank you
    Steven
    p.s. urgent!!

    • Hi Steven, I have added info relating to stairways and balustrades http://sans10400.co.za/stairways/ which you might find useful.
      In addition to this, design requirements are also important i.e. as in structural design (SANS 10400 Part B). In fact design requirements are paramount and anyone designing balustrading should know what the requirements are. Then there are also SANS that relate to aluminium specs i.e. the metal itself. Specs in terms of “glass balustrades” will relate directly to the glass used.
      In all instances the requirements relate to safety.
      In terms of glazing, thickness and glass type will relate directly to the maximum glass area used for the balustrade. You can source this info from SANS 10400 Part N Glazing.
      If I can help further let me know.

  13. Hi, I live in a body corporate. One of our owners has terrible problems with his wooden windows. They are old and rotten, water and wind comes through often damaging carpets etc. This owner wishes to replace these meranti windows with bronze colored aluminium ones all at his own cost. Does he need approval from the municipality to do this? We have contacted 2 different members and one says yes and the other says no. Can you advise? Thanks Brenda

    • Hello Brenda. Providing the windows can be removed and replaced without major structural issues – e.g. walls don’t have to be removed to refit the frames – then there is absolutely no need to have approval from the local authority (municipality).

  14. Hi just wane know is there any way to download SANS XA complete draft download with all fenestration, R and U values details/tabels, glazing etc detail. I do have the first part of XA but there is a part that i dont have and i need it as i cant submit any building plans if i dont have standards.
    Thanks cheers
    Andrew

    • Hi Andrew, unfortunately not. PART X: Environmental Sustainability and Part XA: Energy Usage in Buildings were added to the new SANS and you can only get it from the SABS:
      https://www.sabs.co.za/webstore/standards/product.php?id=1400025021
      It costs R134 + VAT
      If you don’t want to buy it, I suggest you go into your closest SABS office library and ask to see the Standard. You can make notes and they may be willing to photostat a couple of pages for you.
      Good luck
      Penny

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