Choosing and checking loft insulation installers

The two registers to check

TrustMark. The Energy Saving Trust describes TrustMark as a government-endorsed quality scheme for home improvements and says to make sure the installer you choose is registered with it. You can search the TrustMark website for registered businesses in your area. Funded retrofit work under ECO4 is lodged through TrustMark, so a funded installer should be registered.

Competent Person Schemes. The EST also suggests asking which Competent Person Scheme (CPS) an installer belongs to. Membership lets a business self-certify that certain work meets building regulations. GOV.UK publishes the list of current schemes, and each scheme lets you check its members.

Three quotes, compared properly

The EST suggests getting at least three quotes and recommendations before deciding. Comparing them only works if they describe the same job:

The EST’s questions to ask

The Energy Saving Trust suggests asking:

• How much experience do you have with loft insulation?
• Can you provide references or examples of previous work?
• What guarantee or warranty do you offer on the work?
• Will you assess and address ventilation needs as part of the job?
• Will you handle any necessary building regulations or certifications?

The EST’s red flags

Be cautious if an installer:

• pressures you to make an immediate decision;
• offers a quote much lower than others without a clear explanation;
• is unwilling to provide references or proof of certification;
• does not provide a written contract or a clear breakdown of costs.

To those we would add two from other sources on this site: anyone offering to fix a leaking roof with spray foam, which the EST says no insulation should do, and anyone who says your existing mineral wool must be removed because it no longer meets regulations, which the EST describes as misinformation.

Funded jobs are different, slightly

Under ECO4 you often do not choose the installer in the usual way: the installer finds you, or your council or supplier works with particular firms. The checks still apply. Ask which supplier is funding the work, check the installer on the TrustMark register, and expect a retrofit assessment and, for loft work, a pre-existing loft declaration signed by you and the installer. GOV.UK suggests contacting the council or supplier directly if you are unsure an offer is genuine.

How enquiries through this site work

We are an independent guide, not an installer, and we do not recommend individual firms. If you send an enquiry, we pass it to independent firms covering your postcode, and they contact you directly. You check them, compare them and decide, with no obligation. Whether a scheme funds your loft is decided by the scheme, not by us or by the firm.

After the job

Look in the loft. The insulation should be even, uncompressed and about 270mm deep, the eaves clear, pipes and tank lagged and the hatch insulated. Keep the invoice, guarantee and any declaration together, and take photos, as the EST suggests. If something is wrong, go back to the installer first.