Building Regulations Part L (Doc L)
In April 2002 the government introduced new legislation designed to limit heat loss in all dwellings and business premises etc… The requirements are laid out in part L of the current building regulations and in brief, stipulate the use of certain materials, the need for draught-sealing and fire egress.
This new regulation in particular affects the minimum levels of insulation that replacement windows & doors must have when fitted in your home. Levels of insulation are measured as U values. The lower the U value, the better the insulation level. In future what we may have in the past have referred to as "normal" double-glazing - i.e. two pieces of glass separated by a spacer bar is very unlikely to conform to building regulations.
To achieve the required level of insulation it's almost certain some sort of low emissivity (LOW E) glass will have to be used. Typically in the UK this is Pilkington 'K' glass, although there are other products on the market. It may also be necessary for the sealed double glazed units to be Gas Filled (probably Argon).
The Self-Assessment Scheme is referred to as F.E.N.S.A. - Fenestration Self Assessment Scheme. There are currently three schemes in place, operated by Certass Ltd, Fensa Ltd and British Standards Institute, Willowside Joinery subscribe to the Certass scheme.
If your contractor is registered with the FENSA self-certification scheme, that contractor may certify that the work complies with the relevant regulations and you will not need to notify the council.
If the retailer is not a member of a Self-Assessment Scheme or the householder is carrying out the work then they will be required to pay for the building regulations application - check with your local council for costs. The time taken to obtain approval will depend on the local authority concerned.
Its very important that all householders recognise the importance of conforming with these new regulations - its very likely that on any future sale of your property you will need to provide proof that installation conforms with Doc L.