How do I use direct mail to find solar leads, instead of paying for a saturated digital channel?

Is there still a solar market worth writing to?

Yes, and it is growing faster than at any point since the feed-in tariff years. DESNZ’s Solar photovoltaics deployment table for July 2026 records more than 2.1 million solar installations in the UK, “286,000 installations in the past year — the most in any 12 month period”, and 19,800 new schemes on residential buildings in July 2026 alone; the median over the previous twelve months was “over 24,000 installations per month” against around 3,000 a month between 2016 and 2021 (DESNZ, ET 6.3, July 2026 edition, published 27 August 2026, read 19 September 2026). The same table counts 1,742,568 domestic installations in total at the end of July 2026. Set that against MHCLG’s estimate of “25.8 million dwellings in England as of 31 March 2025”, of which 16.6 million are owner-occupied (MHCLG, Dwelling stock estimates, published 21 May 2026): even if every UK domestic installation were in England, fewer than one home in fourteen would have panels. The demand is real and the roofs are still mostly empty. One timing detail worth knowing before you write: HMRC’s notice states that “a zero rate applies to the installation of certain specified energy-saving materials from 1 May 2023 to 31 March 2027”, solar panels and batteries among them, and that from 1 April 2027 they revert to the reduced rate (HMRC, VAT Notice 708/6, last updated 31 January 2024, read 19 September 2026). DESNZ’s monthly figures are provisional and revised as late data arrives, so quote the edition, not “the latest”.

Why is the digital channel for solar leads saturated?

Because everyone who sells solar is bidding for the same clicks, and none of them can bid for a house. LocaliQ’s 2026 search-advertising benchmarks, drawn from thousands of Google and Microsoft Ads campaigns, report that the average cost per click rose again over the past year and that cost per lead “decreased overall for the first time in five years” — a first fall after four years of increases, with Home & Home Improvement still among the more expensive categories (LocaliQ, Search Advertising Benchmarks 2026, updated June 2026, read 19 September 2026). Those are US campaign averages, so treat them as the shape of the market rather than a UK number. The structural limit is targeting: Google’s own help page states that “radius targeting requires setting a radius of at least 1 km around any given location” and that “if you target a small radius or very small location, your ads might only show intermittently or not at all” (Google Ads Help, Target ads to geographic locations, read 19 September 2026). A kilometre contains every roof, with and without panels, owner and tenant, and the platform decides who inside it sees the ad. The phone is worse. In September 2025 the ICO fined a firm that made 2.4 million automated calls promoting solar panels under the names “Energy Hub” and “Energy Saving Team”, restating that “automated marketing calls can only be made to people who have previously informed the caller they consent” (ICO, 25 September 2025, read 19 September 2026). Millions of unwanted solar calls have taught homeowners to hang up; the letterbox has had no such treatment.

What response does a cold letter actually get?

Around one in a hundred, measured, and rising. JICMAIL’s Response Rate Tracker — campaign-level results submitted by fifteen organisations, 4,939 campaigns in the June 2026 edition — puts cold direct mail at a 1% response rate averaged across 2023 to 2025 and warm mail to existing customers at 6.3%, and its headline finding for the year is that “cold and warm direct mail response rates increased by over 20% in 2025” (JICMAIL, Response Rate Tracker 2026, Full Year 2025 update, June 2026, read 19 September 2026). Two of its other findings shape a solar letter: campaigns with both a brand and a response objective achieve up to five times the response of response-only campaigns, and A4 mailers generate around 2.7 times the response of postcards. Two limits to state plainly. The tracker publishes sector benchmarks only where at least ten campaigns exist, and there is no solar or home-improvement row — so any “solar mail gets X%” figure you are quoted has no published basis. And our own production sends are too few to be a dataset; we will publish response data when the count is honest, and not before. The wider case — attention, recall, and why post is usually the only lawful cold channel — is made with sources in our direct mail versus digital-only guide.

Which EPC field tells me a roof has no panels yet?

PHOTO_SUPPLY. MHCLG’s domestic data dictionary defines it as “whether the property generates electricity from solar panels. The proportion of the roof area (%) covered by solar panels is assessed. 0% means that the property does not have solar panels”, and a sibling field, SOLAR_WATER_HEATING_FLAG, records “whether the property uses solar panels to help heat its water. Either a yes or no” (MHCLG, domestic EPC data dictionary, read 19 September 2026). Because a certificate is lodged per property, this is the one public dataset that says, door by door, which roofs an assessor found bare. Its limits are the certificate’s own: the value is what was observed on the certificate’s inspection date, so a home that fitted panels afterwards still reads 0% until it is reassessed; the open data covers “certificates registered since 2012”, so a home with no certificate in that window is invisible; and Scotland’s register is separate and not in this data. Why can an EPC say a home has no solar panels when it does? covers that gap, and how to find homes with no panels detected even where the certificate is out of date. The same certificate carries the fields that make a solar letter specific — the energy rating, the main heating fuel, the roof description and the construction age band — and the register’s licensing page sets out what the address fields may be used for; read it before you build a list, because the non-address fields and the address fields are licensed differently.

How do I build a solar mailing list without knocking every door?

Start from a postcode district, keep only the certificates whose solar field is 0% or blank, then narrow on the fields that make the offer land. Electrically heated homes and lower-rated homes are the ones where the same panels displace the most bought-in electricity, so a first pass is often no panels plus main fuel: electricity or band D to G; a pitched roof in the roof description is a second pass; and the certificate’s tenure field, which is self-declared, tells you whether the reader is likely to own the roof they would be putting panels on. What the certificate cannot tell you is who lives there now or whether they want to hear from you, so write to the Homeowner unless you hold a name from a lawful source, and give every letter an easy way to say stop. This is a method, not a rule from any scheme document: the list shortens the drive and the survey confirms the roof. Two pieces of hygiene make the list defensible — dedupe by property so a home with several certificates gets one letter, and drop any address that has asked you not to write.

What should the letter say, and what must it not claim?

Say why this street, make one offer, and substantiate every number. A property-specific letter can open with what is true of the area — that most roofs on the street have no panels, that homes of this age and heating type spend the most on bought-in electricity — without implying you have surveyed the reader’s house. The advertising rules then belong to you, not to the homeowner: CAP’s April 2026 advice on greener-homes claims states that “traditionally when using ‘up to’ or ‘from’ claims, advertisers need to hold evidence that a significant proportion of customers can actually achieve the maximum saving”, that the price you present must be realistic, and that you must “make clear when that price might be affected by a consumer’s individual circumstances, or if a government grant has already been applied to it” (ASA/CAP, 9 April 2026, read 19 September 2026). So a savings figure needs a basis you can show, the VAT position needs its end date, nothing is free if it costs anything, and there is one call to action — a survey booking, a phone number, a page on your site — not four. On the law of sending it: addressed post is outside PECR’s electronic-marketing rules and inside UK GDPR, where legitimate interests can be the lawful basis for a letter with a clear opt-out (ICO, Direct marketing guidance, read 19 September 2026). This is marketing guidance, not legal advice; check the ICO’s pages against your own campaign before you send.

How do I do this in EcoBrace?

Run a postcode-district search, filter the grid to roofs without panels, and add the result to a Direct Mail campaign — the letter goes to those doors and nowhere else. Enter a district such as ZZ9 (a fictional one — pick your own) and EcoBrace fetches the EPC data live from the official register for every certificate in it. The results grid carries the certificate’s own solar columns — EPC: PV Present, EPC: PV kWp and EPC: SWH — alongside energy rating, main fuel, construction age and tenure, so the narrowing in the passage above is a set of column filters, applied after the search runs. Export the narrowed list to Excel (a paid-account feature) or add it straight to a Direct Mail campaign: a campaign’s recipients come from a search and from nowhere else, up to 1,000 per campaign, deduplicated by property as they are added. Upload your letter as a print-ready PDF — the first document is the one that carries the address — pick a window or closed-face envelope, mono or colour, single- or double-sided, first or standard class, and a despatch date. The proof is free; generating it firms the price for your exact list, and your wallet is charged only when you press Send. A full-postcode search with no extra data is free; a district search is charged on the actual number of postcodes searched, with an estimate shown first as a maximum. The limits are the ones above: the solar field is as at the certificate, the open data starts in 2012, and pay-as-you-go district search is not available in Scotland.

What does this guide not cover?

It does not tell a homeowner whether solar is right for their roof, and it is not legal advice on marketing law — the ICO’s direct-marketing guidance and the register’s licensing page are the documents to read against your own campaign. It also does not publish a response rate for solar letters, because no honest one exists yet.

Where do I start?

Two ways in. Sign up and run a search — a full-postcode search with no extra data is free, there is no subscription and no minimum order, so the first fifty letters can be a test rather than a commitment. Or contact us at hello@ecobrace.co.uk if you would rather talk it through first: which districts, what the letter should say, and whether Scout — the guided version of Direct Mail, where we learn a property profile from your past sales and keep your monthly list full — fits how you sell.