Green home improvement loans compared

In brief

A government-backed green home improvement loan (the Warm Homes Loan) comes with a grant of up to 20% of the loan, cutting the rate by up to around 5 percentage points against the average quoted personal loan rate of around 6.9%.
It only funds low-carbon measures, such as a heat pump to £20,000 or solar to £15,000. An ordinary loan funds anything, but at full price.
Public loans are expected from September 2026, and the loan stacks on the £7,500 Boiler Upgrade Scheme grant.

A green home improvement loan is money borrowed to pay for low-carbon work on your home, and the phrase covers two very different products. One is the government-backed Warm Homes Loan, where a grant of up to 20% of the loan reduces the rate by up to around 5 percentage points. The other is a standard home improvement loan from a bank, which you can spend on a heat pump or a new kitchen alike, with no rate support and no strings. The backed version is cheaper but fussy about what it funds. The ordinary version is flexible but full-price.

Knowing which one you mean matters, because the two are not interchangeable and only one of them has the government paying down your interest.

Where the price gap comes from

An ordinary home improvement loan is priced like any other unsecured personal loan. In the Bank of England's spring 2026 figures, the average quoted rate on a typical personal loan sat at around 6.9%, and that is before a lender looks at your credit file and adjusts up or down. You borrow, you repay with interest, and the lender does not care whether the money buys a heat pump or a hot tub.

The Warm Homes Loan works differently. The government pays the approved lender a grant of up to 20% of the loan, which shrinks the principal the lender charges interest on. That support is what lets the lender knock up to around 5 percentage points off the rate. On a five-figure heat pump loan over several years, a cut of that size is the difference between a repayment that stings and one you can plan around. You can model the monthly figure on the loan repayment calculator once you know the sum you need.

The two loans side by side

The trade-off is straightforward. You accept a narrow list of eligible measures in exchange for a lower rate and access to grant stacking. Here is how the two products line up.

Feature	Warm Homes Loan (backed)	Ordinary home improvement loan
Who sets the rate	Approved lender, rate reduced by a government grant	Any bank or lender, priced commercially
Typical rate direction	up to around 5 percentage points lower	around 6.9%
What it funds	Heat pumps, solar, battery, rural biomass	Almost any home project
Insulation	Not covered	Covered
Grant stacking	Yes, with the Boiler Upgrade Scheme	No
Typical security	Unsecured	Unsecured or secured

For a heat pump or a solar array, the backed loan wins on cost every time it applies. For a loft conversion or a new bathroom, it is not even on the table, and a general loan is the only route.

What the backed loan will and will not fund

The Warm Homes Loan is deliberately narrow. It funds an air source heat pump to £20,000, solar panels to £15,000, plus battery storage and biomass for rural homes, each measure carrying its own cap. The heat pump caps include the radiators, pipework and tank the system needs, not just the unit, which is where installs tend to run over. Our heat pumps guide and solar guide set out what a realistic quote looks like for each.

Insulation is the line the scheme will not cross. Cavity walls, loft top-ups and solid wall insulation all sit under the separate, means-tested Warm Homes: Local Grant, not the loan. So if your home needs insulating before a heat pump makes sense, the loan cannot fund that first step. An ordinary green home improvement loan can, because it funds anything, but you pay the full commercial rate for the privilege.

Secured or unsecured, and why it matters

Home improvement borrowing comes in two shapes. An unsecured loan is lent against your income and credit record alone; nothing is pledged, and the sums are usually smaller. A secured loan, sometimes sold as a homeowner loan or second charge, is tied to your property, which lets you borrow more over a longer term but puts the house at risk if you fall behind.

The Warm Homes Loan is built around unsecured lending through its approved lenders, so for most people it will not place a charge on their home. That is a meaningful protection compared with a large secured loan taken for the same job. If a lender ever offers you a secured green improvement loan, read the term and the total interest carefully; a longer term at a lower monthly cost can still mean more interest paid overall, and your home is on the line. The comparison is worth running before you sign anything.

When borrowing now beats waiting

Timing is the quiet variable. Public Warm Homes Loans are expected from September 2026, which is close. If your measure is on the funded list and the work can hold for a few weeks, waiting for the backed rate almost always beats borrowing today at a full commercial price. The saving compounds over a 3 to 10 year terms.

Waiting stops paying when the job cannot wait. A dead boiler in autumn, a leaking system, a rental that must hit an energy standard by a deadline: those force the timeline, and an ordinary loan bridges the gap. There is also the stack to weigh. Because the Warm Homes Loan sits on top of the £7,500 Boiler Upgrade Scheme grant, a heat pump buyer who waits can take the grant first and borrow only the balance at the reduced rate. For the umbrella that both of these sit under, our explainer on the warm homes plan 2026 maps the full set of pots.

Common questions

Is a green home improvement loan cheaper than a normal loan?

It can be. The Warm Homes Loan pairs your borrowing with a government grant of up to 20% of the loan, which lowers the rate you pay by up to around 5 percentage points. Against an average quoted personal loan rate near 6.9%, that gap is the whole reason the scheme exists.

What can a green home improvement loan pay for?

The Warm Homes Loan funds low-carbon measures: air and ground source heat pumps, solar panels, battery storage and rural biomass, each with its own cap. It does not pay for insulation, which sits under the separate Warm Homes: Local Grant. A general home improvement loan carries no such restriction but no rate support either.

Is the Warm Homes Loan secured against my house?

The scheme is built around unsecured lending through approved lenders, so most borrowers will not put their home up as security. Ordinary home improvement loans split both ways: smaller sums tend to be unsecured, while larger secured loans use your property as collateral and put it at risk if you default.

Should I wait for the Warm Homes Loan or borrow now?

If the job can wait until public loans arrive from September 2026 and your measure is on the funded list, waiting usually pays. The rate cut and the ability to stack the Boiler Upgrade Scheme grant on top rarely beat borrowing early at a full commercial rate.

Before you compare a single rate, settle which loan you are even eligible for, because a backed loan and a commercial one answer different questions. The funding wizard checks your measure against the scheme rules and points you at the loan, a grant, or both, so you do not spend an application on the wrong door.