Harvey Knowles Ltd

The registered company name, registered office address, Companies House number and incorporation date, all taken from the public Companies House register. It does not include reviews, prices, staff details, or confirmation that the company is currently trading.

Not much, but not none. Wipe the frames a few times a year, lubricate hinges and locks annually, and keep the drainage channels along the bottom of the frame clear so water can't pool and find its way inside. There is no statutory annual service like a boiler needs.

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.