Building Regulations for Replacement Windows and Doors

The five regulation areas that affect a replacement job, and who certifies the work.

Replacement glazing is notifiable work. That means the installation has to meet defined standards and be certified — either through a competent person scheme or through local authority building control.

These are the areas that come up on almost every job.

Thermal performance

Replacement windows and doors must meet a minimum energy performance. In practice this means the glazing unit, spacer and frame system have to be specified together, not chosen separately on price.

Safety glazing

Glass in critical locations — low-level panes, doors and side panels next to doors — must be toughened or laminated. This is not optional and it is a common corner-cut in cheap quotes.

Means of escape and ventilation

Certain rooms require an escape window of a minimum clear opening size, and existing background ventilation must not be reduced by the replacement. Both affect the opener layout, which is why survey matters.

Certification

We are Certass registered, so we self-certify compliant installations and register them. You get documentation without a separate building control application.

Want the compliance side handled?

We specify to the regulations and register the work, so the certificate arrives without you chasing it.

Frequently asked questions

Does every replacement window need certifying?

Replacement of a whole window is notifiable. Replacing only the glass in an existing frame is treated differently.

What if my property is listed?

Listed buildings and conservation areas have additional consent requirements that sit alongside building regulations.

Will I get paperwork for selling the house?

Yes — registered installations produce a certificate that solicitors commonly request.

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