Warm Homes Plan solar loan

Where things actually stand in October 2026

I’ve lost count of the pages telling people this loan launched in September. The rules do say that. The reality is that you still can’t apply for one.

Here’s the sequence, because it matters. The Warm Homes Plan landed on 21 January 2026 with £15 billion attached. Inside it sat a promise of “low and zero-interest loans” for solar panels, batteries and heat pumps. That promise now has a name, the Warm Homes Loan Scheme, and a 53-page rulebook from the Department for Energy Security and Net Zero.

DESNZ opened the first lender application window in June 2026. It closed on 17 July. The Scheme Rules were refreshed in September 2026, and they set out an initial consumer launch phase from September 2026. A privacy notice for borrowers appeared on 17 September, which is usually a sign that a launch is close.

And then nothing. As I write this in late October 2026, the only live pages on GOV.UK are aimed at lenders. No participating lender has been named. No product exists. No rate has been published. A second application window is expected before the end of 2026, with those lenders onboarding in early 2027.

One telling detail: when the North East Combined Authority approved its own retrofit loan in 2026, its published decision report described the Warm Homes Plan scheme as not expected to be operational until 2027. A combined authority built its own product rather than wait. That tells you something about how firm the September date was.

How the discount actually works (it’s not a grant for you)

This trips people up constantly, so let me be blunt about it. You do not get a cheque. The government’s money never touches your bank account.

What happens is this. A bank, building society or credit union joins the scheme. When it lends you money for solar panels, the government pays that lender a one-off capital grant of up to 20% of your loan. In return, the lender must knock the full value of that grant off your interest rate. DESNZ calls it a principal-reducing capital grant. The lender is still on the hook for the whole loan at the lower rate — the grant just shrinks the slice of the principal it has to fund commercially.

So the thing being subsidised is the price of the borrowing, not the price of the panels. Three consequences follow, and they’re worth sitting with:

• You still owe the full amount. A £10,000 loan is £10,000 of debt, however cheap the interest.
• You still get credit-checked. There’s no income threshold in the scheme, but your lender’s normal affordability and credit rules apply in full, under FCA conduct requirements.
• The grant is paid in arrears. DESNZ only pays the lender after MCS has verified your installation.

Lenders are audited on whether they pass the whole subsidy through, and DESNZ can claw the grant back if they don’t. That’s a genuinely useful protection, and it’s more than you get with a lot of solar panel finance in the UK.

What you can borrow: the caps, measure by measure

Each technology has its own ceiling on the amount of loan that can attract the subsidy. You can spend more than the cap — the scheme just won’t discount the excess, and your lender is free to offer you an ordinary loan alongside for the rest.

The rate you’ll really pay, and why a longer loan gets a smaller cut

There is no single advertised rate, and there never will be. Each lender sets its own starting rate — what DESNZ calls the Market Rate, meaning what that lender would charge you for an equivalent unsubsidised home-improvement loan. The subsidy then aims to cut up to five percentage points off it.

Two hard limits sit on top. The grant can’t exceed 20% of your loan, and your rate can’t go below zero. Loans must run three years or longer to qualify at all.

Now for the bit almost nobody explains. Buying five percentage points off a loan costs more the longer that loan runs, because the discount applies for more years. On a long enough term, the 20% cap bites before you get your full five points. So a ten-year loan can end up with a smaller rate reduction than a five-year one.

What does that mean in money? Take a £7,350 solar installation on a five-year loan. At a 9% market rate you’d pay roughly £153 a month and about £1,800 in total interest. Drop that to 4% and you’re at around £135 a month and £770 in interest. The subsidy is worth a little over £1,000 to you across the loan.

Who can borrow

The eligibility rules are refreshingly broad. There’s no means test, no minimum EPC band, no property-type restriction at scheme level.

Geographically it’s the whole UK: any domestic property in England, Scotland, Wales or Northern Ireland qualifies, and the scheme is designed to sit alongside the devolved schemes rather than replace them.

One caveat on the “no EPC requirement” point. DESNZ doesn’t impose one, but the rules explicitly allow lenders to add their own criteria, and an EPC is given as the worked example. Some lenders will almost certainly ask for one.

What’s covered, and the three gaps that catch people out

The generous bit first. A solar quote funded this way can include scaffolding, temporary safety equipment and your grid connection. It can also include an EV charge point and its electrical work, provided that’s fitted as part of the solar or battery job — a charger on its own isn’t eligible, and the installer and unit must be OZEV approved. If you’ve been weighing up a solar and EV charger combo, that’s a meaningful sweetener.

Now the gaps, none of which I’ve seen spelled out elsewhere.

That roof point deserves emphasis. A fair number of UK homes need remedial roof work before an installer will fit panels, and the cheap money stops exactly where that work begins.

The quote your lender will demand

If you take nothing else practical from this piece, take this. The Scheme Rules set out precisely what a quote must contain before a lender can approve your application, and a quote that misses any of it will bounce. Worth knowing now, while you’re still choosing an installer.

1. 1
   Dated within the last six months

   An older quote won’t do. If you gather quotes now and the scheme opens next spring, you may need them refreshed.

2. 2
   From an MCS certified installer, with the MCS number on it

   Not just any electrician. The product must be MCS certified and fitted by an MCS certified installer to the relevant standard. Lenders verify this through a direct data link with MCS. What the MCS badge actually means is worth five minutes of your time.

3. 3
   On headed paper, addressed to you, showing the full install address

   Generic estimates and email quotes without letterhead are explicitly out.

4. 4
   Itemised, with the system size in kW

   A single bottom-line figure won’t pass. You need a cost breakdown of every improvement and the capacity of the measure stated.

After the work is done, your installer lodges it in the MCS Installation Database, which generates the certificate your lender needs to claim its grant. If that lodgement doesn’t happen, the subsidy doesn’t flow.

Wait for the loan, or buy before VAT rises?

First, let’s kill a myth that’s everywhere right now: the April 2027 VAT change is a five point rise, not a twenty point one.

Qualifying energy-saving installations have been zero-rated since April 2022. That relief ends on 31 March 2027, and from 1 April 2027 the rate reverts to the 5% reduced rate — not the 20% standard rate. Before 2022 these installations sat at 5% too. The House of Commons Library confirmed in September 2026 that the government has given no indication it intends to extend the zero rate.

Set that £350 against what the loan saves you, and the decision falls out cleanly. It depends entirely on how you were going to pay.

The gamble in that third row is real, though. You’d be holding off on an installation to wait for a product that has no launch date, no named lender and no published rate, in the hope it arrives before the relief expires. If the second lender window runs to the end of 2026 and onboarding lands in early 2027, the overlap with the VAT deadline is measured in weeks.

There’s decent evidence the subsidy will work when it lands. Researchers at the LSE’s Grantham Research Institute studied Scotland’s interest-free Home Energy Scotland loan and found it genuinely increased household solar adoption despite Scotland’s weaker solar resource, shifted take-up towards smaller systems, and helped lower-income households most. Cheap borrowing changes behaviour. The question is whether it arrives in time to change yours.

If you want to run your own numbers, our 2026 cost guide by system size and the piece on what the 5% VAT rise really costs will get you closer than any rule of thumb.

Cheap loans you can actually get today

Here’s what frustrates me about the coverage of this scheme. Everyone is writing about a national product that doesn’t exist, and nobody mentions the regional ones that do. Several councils and combined authorities already run low-interest retrofit loans, mostly through a social enterprise lender called Lendology CIC, and the rates beat anything on the high street.

Beyond public schemes, the ordinary market hasn’t gone anywhere. Installer point-of-sale finance, green loans and further advances all exist today — our guide to solar with no upfront cost walks through every route and the catches in each.

Scotland, Wales and Northern Ireland

The loan scheme itself is UK-wide, which is unusual and welcome. The surrounding support is not.

The small print worth reading before you commit

I went through all 53 pages so you don’t have to. Four things stood out that I haven’t seen covered anywhere.

Finally, the whole thing carries a standing caveat: DESNZ reserves the right to amend any position in the rules with 30 days’ written notice, and to end the scheme altogether. Changes won’t apply retrospectively, which protects anyone who has already borrowed.

Your questions, answered