Darvell's Joinery Limited

A single uPVC window in Watford typically runs £300 to £600 supplied and fitted; a full house of 8 to 10 windows is often £3,000 to £8,000 depending on style (casement, bay, sash-look) and glazing spec. Get two or three written, itemised quotes before agreeing to work.

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.

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 456 active window and glazing businesses across 61 towns in Hertfordshire, all from the Companies House register. Watford accounts for 56, among the county's busiest. About 31% of Hertfordshire'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.