Double glazing requirements

Introduction

In April 2002 the Government introduced legislation designed to conserve heat loss in private houses. The requirements are laid out in Building Regulations Approved Document L (Fuel Conservation), and require all windows and doors in newly built houses; and complete replacement windows and doors in old housing stock to be double-glazed using a low emissivity glass. Other Building Regulations must also be complied with.

If non-compliant units are fitted, the value of the house may be diminished and the homeowner can be faced with a fine. When selling the property, evidence will be required to show that any replacement glazing installed since April 2002, complies with the Building Regulations. There are currently two ways to prove compliance:-

• a certificate from the Local Authority Building Control Service stating that the installation has been approved under the Building Regulations OR
• a certificate showing that the work has been done by an installer who is registered with FENSA

FENSA stands for the Fenestration Self-Assessment Scheme. It was set up by the Glass and Glazing Federation (GGF) and other industry bodies, at the request of the CLG, to allow registered companies to self-certify that their installations comply with current Building Regulations.

Building Regulations

Approved Document Part L (Fuel Conservation) covers the improved energy efficiency requirements for new and replacement windows. They must also comply with Approved Document Part N (safety in relation to impact). For example, windows and doors in critical locations ie windows below 800mm from floor level and doors where the glass comes within 1500mm of the floor level to the start of the glass, must contain safety glass, (toughened or laminated) and must include the relevant safety mark clearly visible.

In addition, the building should not end up with a worse level of compliance with respect to other applicable parts of the Building Regulations, which includes Part A (structure), B (means of escape from fire), F (ventilation), J (combustion appliances and fuel storage systems) and M (access for the disabled). Compliance with Gas Safety (Installation and Use) Regulations 1998 is also essential where appropriate.

Building Regulations for replacement windows state that the situation must be made 'no worse than the outgoing windows' for example if the old windows had trickle vents, so must the new ones; new openings cannot be made smaller; side windows cannot be replaced by top openings over fixed windows.

It is important to ensure that any new window or doors fitted can be shown to be compliant. There are two ways of gaining certification to show this. 

Applying for planning approval 

Any installation undertaken by a company which is not registered with FENSA or a similar body, or has been done as a DIY project by a homeowner, will need full Local Authority Building Control approval. As Local Authorities will have been informed of the registered businesses in their areas and can identify unauthorised work. This method is time-consuming and costly, requiring inspection by council officers.

Having the work performed by a FENSA registered company

The second, easier, way is to have your work carried out by a FENSA registered company. Many companies are registered with FENSA and therefore authorised to fit compliant windows without supervision. Once fitting is complete, these companies will issue a certificate for your records and the registered company gives you an insurance backed guarantee.

A percentage of the work of every FENSA registered business will be inspected by a FENSA appointed inspector to ensure standards are met and maintained. Inspection will normally be carried out on 1% of each business's installations, subject to a minimum of two per annum and a maximum of 100. In the event of failed inspections, businesses will be responsible for the costs of re-inspection, and the frequency of inspections will increase.

Once registered, companies will be required to certify that their work complies with the regulations, and inform a central FENSA database whenever they carry out an installation. The database will then be used as the source for certification to Local Authorities that installations have taken place, producing certificates for homeowners, and for subsequent reference, by solicitors doing search activities prior to house purchases. FENSA will inform local authorities of all completed registered installations and will issue a certificate to the homeowner confirming compliance.

Requirement for businesses to insure the consumer

FENSA Registered Businesses are required to have in place for their customers the two categories of insurance.

If Registered Businesses take deposits in advance of installations, they must give some form of deposit indemnity. Deposits may be guaranteed by, for example, trade association Deposit Indemnity schemes, or credit card protection.

A Registered Business must also give a guarantee or warranty covering the cost of completing rectification work in respect of defects and in the event of ceasing to trade, offer to back this guarantee with an independent insurance policy.

The basic requirement from FENSA is that the insurance-backed guarantee is offered. Some companies may prefer to make this offer at the time of sale, whilst others may defer it until the order is confirmed. In some cases, the insurance provider may wish to make the offer themselves, since their staff are likely to be more qualified than the glazing salespersons.