FENSA
FENSA and Building control regulations in the UK, 
mainly document L

Building control is the process whereby plans and construction work are measured against the requirements of the Building Regulations.

FENSA (FENESTRATION - SELF ASSESSMENT) and Building Regulations

Although the ramifications as well as the opportunities are great for our industry and for the public/consumer, only those with a stubborn resistance to change would have us stand still when the technologies are available for us to conserve energy further and take us on to this next step forward.
As for double glazing and windows and doors, yes, it is true, all makes will now have to 'toe the line' and many will have to make some fundamental improvements as a minimum standard to meet these Regulations next year. It is interesting to note that the early information I have indicates that the maximum air gap for sealed units is likely to be recommended at 16mm (24mm overall), and not the 20mm (28mm overall) that many double-glazing salesmen would like you to believe is a 'must have'.

Sealed-unit manufacturers also have to conform with EN 1279, the more stringent European Standard, which replaces the Kite mark BS 5713. These Regulations came into force from April 2002, but there is a lead-in period of 18 months for companies to comply.
Part L and EN 1279 are both mandatory, which means they can be legally enforced.

Changes to Part F about double glazing will also affect everyone in the glazing industry, because when replacing windows from April 2002 adequate background ventilation of a minimum 8000 mm2 must be provided for all habitable rooms, and 4000mm2 for bathrooms, etc. The intention is to save us from ourselves by mandatory ventilation, thus reducing the likelihood of our living in an unhealthy indoor environment with lots of condensation.
Having dealt with energy efficiency to some degree in the April 2002 changes with the introduction of Building Regulations Doc L in England, the Government will next look at the impact of ventilation within the home. This will also be in relation to noise, which is seen as a main cause of irritation to householders; and also air quality, which all might form the new part E.

News as of September 2002
F.E.N.S.A. inspections encompass more than just doc L, i.e. not just low e glass etc. This update applies to England only.

Front doors with less than 50% glass are exempt, i.e. doors with insulated feature panels will not normally need low e glass, particularly as the overall U value will meet the requirements.
When fitting doors or windows to an unheated area that is not part of the house, i.e. garage or outbuildings, Building Regs do not apply.

I quote from FENSA: 
‘The Building Regulations Approved Documents N (Safety Glazing) and L (Thermal Insulation) are prime requirements for replacement windows and doors. Other elements of the Building Regulations A (Structure), F (Ventilation), B (Means of Escape), J (Combustion Appliances and Fuel Storage Systems), M (Disabled Access) must not be compromised by the replacement installation.’

Double glazing trade: 
This means not only that you must comply with the Regs, but that, when you fit your replacements, you must not make these things worse than they were before.

New double glazing in bay windows is now being checked by FENSA during installation, particularly as load-bearing metal poles MUST go through the sill, with structural bearing header and spreading plates, that is, above and below. Bay windows must now be registered as the number of windows/facets, so a fivelight bay is registered as five windows.
Entrance doors are being checked for threshold height and access for the disabled.
In some cases lock ajar will qualify as trickle ventilation, but compliance with the Gas Safety (Installation and Use) Regulations of 1998 is essential. 

Download What the Building Inspector will be looking for in new double-glazing installations
This is in PDF format. If you do not have Adobe PDF Reader then you can download it here:

News as of end-March 2003
GGF discuss Window Ratings, Conservatory Regulations and the GGF Conference at Glassex, March 2003.

Double glazing and window ratings - the next step?
What with all the talk of Building Regulations for double glazing and the future, it was interesting to hear what the British Fenestration Ratings Council (BFRC) had to say at the Energy Saving Trust's seminar in the Lecture Theatre on Tuesday 25th March 2003 at Glassex. It would seem that Dr Robin Kent and Kevin Cubbage have gone a long way towards developing a ratings scheme, which could work for the industry. Their negotiations in Europe and work on developing a European Window Ratings Scheme (EWRS) incorporating A-G ratings and a 'label' - similar to those found on fridges and washing machines - would seem to have borne fruit if the response from Tuesday's audience was anything to go by.

'This could this be the next step in the industry's campaign to gain further recognition for the energy efficiency of their products and at the same time raise awareness amongst consumers,' said Nigel Rees, GGF Chief Executive. Next thing for England is that our Regs will be as tough as the newer Scottish ones, inasmuch as we will all have to use 'soft coat' low e glass, and Pilks K will not be good enough, within a year or two or so - watch this space.

MS Word quick 141KB download:
"Possible Future Performance Standards for Building Regulations part L"

Will insulated cavity closers be required to be fitted by window installers in the future?
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Information about double glazing & building regulations on the BRE website