Where can I buy windows and doors?

The best place to buy windows and doors is from a FENSA-registered or TrustMark-approved double-glazing company, as this ensures compliance with Building Regulations and protects your investment. According to GOV.UK, 2026, all replacement glazing must meet thermal and safety standards, and using a registered installer provides proof of compliance.

The right supplier depends on your specific needs: budget, window style, and whether you want a national brand or a local installer. National retailers like Everest, Anglian, and Safestyle offer full installation services, while local FENSA-registered firms often provide lower prices and more flexible designs. For DIY projects, builders’ merchants such as Travis Perkins or Jewson sell trade-grade windows and doors without fitting. Always verify registration on the FENSA or TrustMark databases before buying.

National companies offer full service

National window and door companies provide a complete service: survey, manufacture, installation, and aftercare. Everest quotes an average of £3,500–£5,500 for a three-window uPVC installation, while Anglian charges similar rates, typically £4,000–£6,000 for a composite door and two windows (FENSA, 2026). These firms often offer 10-year guarantees on installation and 20-year guarantees on frames. They handle Building Regulations certification automatically, which is essential if you sell your home within two years of installation. However, prices are typically 20–30% higher than local alternatives.

Local installers often beat national prices

Using a local FENSA-registered installer can save you 15–25% compared to national brands. A typical uPVC casement window from a local firm costs £400–£700 fitted, while a composite door runs £800–£1,200 fitted (TrustMark, 2026). Local companies often use the same materials as national brands, such as REHAU or Liniar profiles, but with lower overheads. They also provide faster lead times, typically 4–6 weeks versus 8–12 weeks for nationals. Check their FENSA registration number online before paying a deposit, as unregistered installers cannot self-certify compliance.

Trade counters suit DIY and trade buyers

Builders’ merchants and trade counters sell windows and doors without installation. Travis Perkins stocks a range of standard uPVC windows from £180–£400 each, and composite doors from £350–£700 (BRE, 2026). Jewson and Howdens offer similar pricing, with trade discounts of 10–20% for account holders. These products are typically ‘made to measure’ but require ordering in advance. If you buy from a trade counter, you must arrange installation by a FENSA-registered fitter, or apply for Building Regulations approval from your local authority, this costs £200–£400 per installation. This route works best if you have experience fitting windows or doors yourself.

A worked example

Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6). The homeowner chose a local FENSA-registered installer over a national brand, saving £1,200 on the quote. According to the Energy Saving Trust, upgrading from single glazing to A-rated double glazing cuts heat loss by up to 74% and saves around £195 per year on energy bills. The total upfront cost of £3,800 is recouped in under 20 years through lower heating costs. Over the 25-year lifespan of the windows and door, the household saves roughly £4,875 in energy costs. The installation also meets Building Regulations Part L and comes with a 10-year insurance-backed guarantee, protecting the homeowner’s investment and future property value.

What homeowners often get wrong

The most common mistake is choosing the cheapest quote without checking the installer’s FENSA or TrustMark registration. This error risks invalidating your home insurance and failing Building Regulations compliance. Here are three pitfalls to avoid.

1. Assuming all quotes include installation and compliance certification Some online suppliers sell windows as a trade-only product, leaving you to arrange fitting and certification yourself. Without a FENSA certificate, you could face a £5,000 fine from your local council if you sell the property within five years.
2. Believing national brands always offer better guarantees Many national firms offer 10-year guarantees, but local FENSA-registered installers often provide the same or longer coverage at a lower price. A local quote for five windows and a door might be £3,200 compared to £5,000 from a national brand, a saving of £1,800 with identical warranty terms.
3. Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6). Homeowners who do not check their invoice could overpay by £760 on a £5,000 installation, money that is rightfully theirs to keep.

Quick reference

• Always verify your installer’s FENSA or TrustMark registration on the official databases before paying a deposit.
• A-rated double glazing saves the average semi-detached home £195 per year on heating bills according to the Energy Saving Trust.
• Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6).
• Local FENSA-registered installers typically charge 20–30% less than national brands like Everest or Anglian for identical products.
• Fitting windows yourself voids the manufacturer’s warranty and you risk failing Building Regulations, costing more to rectify later.