Eco home installers in Westminster

Local buying guide for Westminster

This is a summary of the main points from our UK buying guides, set out for homeowners in Westminster. Prices are UK averages for 2026, so quotes in your area can come in higher or lower. Use the figures to judge whether a quote is sensible, then read the full guide before you sign anything.

Windows and doors

• Expect to pay about £450 to £1,200 for each double glazed window, fitted. Most homeowners pay £650 to £950. Replacing old single glazing saves roughly £195 a year on heating; swapping one good uPVC window for another rarely pays back.
• A composite front door costs about £1,200 to £1,800 supplied and fitted. Add £200 to £500 if the frame also needs replacing. Look for PAS 24 security certification and multi-point locking.
• New windows must meet current thermal standards (a U-value of 1.4 W/m2K or better). In England and Wales ask for a FENSA or Certass certificate when the job is finished, because it is your proof the work complied with building regulations.
• Argon filled units and warm edge spacer bars both cut heat loss. Triple glazing is mainly worth the extra money in colder, more exposed parts of the country.
• Listed buildings need listed building consent before you change windows or doors, and conservation areas often restrict the style and material. Ask your council before you order.

Read more: Double glazed windows buying guide | Composite front doors buying guide

Grants and support in England

• The Boiler Upgrade Scheme gives £7,500 towards an air source or ground source heat pump in England and Wales.
• ECO4 and the Great British Insulation Scheme have helped eligible households with insulation and heating, and the Home Upgrade Grant supports low income homes that are off the gas grid.
• Your local council may run its own energy efficiency scheme, so search your council's website for "energy efficiency grants".
• Schemes open and close, and the rules change. ECO4 and the Great British Insulation Scheme were due to end in March 2026, so check GOV.UK for what is open now before you rely on any grant.
• Insulation and heat pump grants usually require an assessment first, and the work must be done by a registered installer. Never pay anyone who offers a grant "on your behalf" without checking it on the official scheme website.

Read more: ECO4 scheme guide | Home Upgrade Grant guide

How to check an installer in Westminster

• Ask for the right registration for the job: MCS for heat pumps and solar, FENSA or Certass for windows and doors, Gas Safe for boilers, TrustMark for insulation and wider retrofit work. Then check it on the scheme's own website instead of trusting a logo.
• Read the most recent Google reviews, not just the star rating, and look at how the company answers complaints.
• Get at least three written quotes that list the products, the brand and model, the total price including VAT, and a start and finish date.
• Ask how your deposit is protected. An insurance backed guarantee is the safest, and you should never pay the full price in advance.
• If you sign a contract at home you normally have a 14 day cooling off period. Keep your copy and read the cancellation terms.
• Ask to see a recent job nearby and, if you can, speak to the homeowner.

Questions to ask on every quote

• Who will do the work, your own staff or sub-contractors?
• What exactly is included: removal and disposal of old units, making good, decorating, scaffolding?
• What guarantees come with the product and with the workmanship, and who backs them if the company closes?
• How long will it take, and what happens if the price changes part way through?
• Will you handle the certificate or notification to building control, and when will I receive it?