New Building Standards for Scotland: Part J - Update

Scotland got its own new Building Standards on the 1st March 2003 with the full implementation of Part J. This Building Standard requires an even higher performance level from a window than in England and Wales. 

Replacement windows and doors in Scottish dwellings are expected to achieve U values 10% lower than those in England and Wales, which means a difference of 0.2 of a U value compared to England and Wales. Soft coat Low E Glass with a 16mm cavity containing an inert gas will be necessary in most cases.

This means that in most existing dwellings, replacement windows will then need to have a U-value of not more than:

• 1.8 for windows made of plastic or wood
• 2.0 for windows with metal frames

A U-value is a measure of heat-loss from a building; the lower the value the better the performance.

Please Note: Contracts signed up to the 28th February must be started by 1st May and fully installed by 1st July 2003.

Can I put in windows of poorer performance?

Generally, no. However there are sometimes exceptions:

1. When a particularly energy-efficient gas or oil-fired central heating boiler has recently
been installed in your house, your replacement windows may be able to have a slightly lower standard. If you think your boiler may qualify, speak to your glazing installer who will be able to advise on the written confirmation that he needs from you; or

2. If you put in windows that are close to being identical to the ones that you are taking out. This will usually occur when your house is "Listed" as being of historic interest.

How will anyone be able to tell if I don't install the correct windows?

If you don't have the correct specification of window installed, you may have problems selling your house in the future. When you eventually come to sell your house, a surveyor may use a glass analysis gauge to establish whether or not the correct glass has been used. If the glazing is wrong, you may have problems with the house sale.

Do I need building control approval?

Not as such, however your windows do need to comply with all other appropriate aspects of the Technical Standards to the Scottish building regulations - e.g. emergency escape, safe-cleaning, safety glass and ventilation.

What about windows in an alteration or extension to a dwelling?

Generally speaking the above rules still apply. However you will need building control approval from your local council. They will be able to advise on the drawings and specifications they need to process your application.

Additional Notes:

A guidance sheet consisting of questions and answers has been developed to assist Building Control Officers. Based on the GGF's data sheet 2.2, it will be used to validate the U values of a window and therefore a product range. Scotland will also get their own version of the GGF's Low Emissivity Glass information sheet.

The Construction Licensing Executive is currently devising a self-regulation scheme through membership registration for the Scottish area. It will have similar bearings as the Quality Mark scheme in England and Wales, more than that it will resemble FENSA.

Sources for this article include:

Building Regulation Note 1/2003 
BUILDING STANDARDS (SCOTLAND) REGULATIONS 1990 (AS AMENDED)
Issued 21st February 2003

View online at http://www.scotland.gov.uk/library5/development/brn103.pdf

Also see http://www.glassandglazingfederation.org.uk/view_doc_aps.phtml?id=71

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