D Breslin Joinery Ltd

Not here. This is a register-based directory, not a review site. Look at independent review platforms, ask the installer for recent local references, and confirm FENSA or Certass registration before any work starts.

Repair makes sense for a failed seal (misted double glazing), a worn handle or hinge, or a damaged lock on an otherwise sound frame — usually a straightforward swap. Replacement is the better value once frames are warped, draughty, rotten (on timber) or past roughly 20 to 25 years old, or when several units across the house have failed. Ask the installer to price both where it's borderline.

uPVC frames typically carry a 10 year manufacturer or insurance-backed guarantee, and sealed glazed units are usually guaranteed separately for 5 to 10 years against misting. Register the guarantee after installation and keep the FENSA or Certass certificate — a buyer's solicitor will ask for it if you sell the property.

It's proof the window or door installation meets Building Regulations (thermal performance, safety glazing, ventilation) without a separate council building control sign-off. Without one, selling the property can mean paying for retrospective building control inspection or indemnity insurance, so keep the certificate with your house documents.

This directory holds 524 active window and glazing businesses across 79 towns in Belfast, all from the Companies House register. Londonderry accounts for 31, among the county's busiest. About 38% of Belfast's registered window and glazing firms were incorporated in the last three years, so weigh incorporation date and FENSA/Certass registration, not just company age.