Best Timber Windows in London

How to Choose a Timber Window Company

London has dozens of companies offering timber windows. The quality varies enormously — from mass-produced imported joinery sold as “bespoke” to genuine made-to-measure windows from specialist workshops. Choosing the wrong company can mean poor-fitting windows, premature rot, failed glazing units, and expensive remedial work. Here is what to look for.

What to Check Before You Buy

1. FENSA or CERTASS Registration

Any company installing replacement windows in England and Wales must be registered with a competent person scheme (FENSA or CERTASS) or obtain separate Building Control approval. A FENSA-registered installer self-certifies that the work meets Building Regulations and provides a certificate you will need when selling your property. No certificate means no compliance — and a potential problem at sale.

2. Timber Species and Construction

Ask what timber is used. Engineered hardwood (Accoya, Sapele, Iroko) and laminated softwood last far longer than cheap solid softwood. Engineered sections resist warping and twisting. If the company cannot tell you exactly what timber they use, that is a red flag.

3. Paint System

Factory-applied microporous paint systems (such as Sikkens) outperform site-applied paints by a wide margin. A proper factory finish includes primer, undercoat, and topcoat applied in controlled conditions. Ask about the coating system — if it is “primed only” or “painted on site,” expect shorter intervals between maintenance.

4. Glazing Specification

Check the glazing unit specification: glass thickness, gas fill (argon or krypton), spacer bar type (warm-edge vs aluminium), and U-value. Warm-edge spacer bars reduce condensation at the glass edge and improve thermal performance. Aluminium spacers are cheaper but create a thermal bridge.

5. Security Standard

PAS24 is the recognised security standard for windows in the UK. It tests the entire window assembly — frame, glass, and locking mechanism — against forced entry. Not all timber windows meet PAS24. Ask for the certificate.

6. Conservation Area Experience

If your property is in a Conservation Area, choose a company with proven experience in your borough. They should know the local planning requirements and be able to produce windows that satisfy conservation officers without you having to manage the process.

Red Flags to Avoid

• High-pressure sales — “This price is only valid today.” Reputable companies do not use pressure tactics.
• No factory visit — if they cannot show you where windows are made, they are probably reselling imported joinery.
• Vague specifications — if the quote does not specify timber species, glass specification, paint system, and security standard, you cannot compare like for like.
• No FENSA registration — non-negotiable for replacement windows.
• Deposit over 25% — industry standard is 0–25% deposit with balance on completion.

Why We Are Different

We publish our prices online. You can design and price your windows in our 3D configurator before speaking to anyone. Every quote specifies timber species, glass specification, paint system, security standard, and warranty terms. We are FENSA registered, PAS24 certified, and manufacture every window in our workshop near London. No middlemen, no resold imports, no surprises.