What's actually different between a personal loan, a secured loan and a further advance?

These three routes to financing a renovation aren't interchangeable: they trade off speed, size and risk in different ways. A personal loan is unsecured, usually arranged within days, and doesn't put your home directly at risk if you fall behind. Lenders typically cap unsecured borrowing at somewhere between £25,000 and £35,000 depending on your credit profile, and the rate reflects that higher risk to the lender. A secured loan, sometimes called a second charge mortgage, is secured against your property alongside your existing mortgage, which usually means you can borrow more over a longer term. Your home is directly at risk if you miss payments, though, and there are typically arrangement fees on top. A further advance means going back to your existing mortgage lender and asking to borrow more against the same property, priced at mortgage-level rates rather than loan rates.

So if speed and simplicity matter more to you than shaving off every last percentage point, a personal loan is worth quoting even if it isn't the cheapest option on the table.

What does £15,000 over 5 years actually cost on each option?

Numbers make this easier than percentages alone. Using representative rates of 7.9% for a personal loan, 9.5% for a secured loan and 4.57% for a further advance (Moneyfacts, July 2026), a £15,000 renovation over a 5-year term breaks down very differently depending on which door you walk through.

£15,000 over 5 years: the three options compared

Personal loan at 7.9%: roughly £303/month, total repayable around £18,200 (about £3,200 in interest). Secured loan at 9.5%: roughly £315/month, total repayable around £18,900 (about £3,900 in interest). Further advance at 4.57%: roughly £280/month, total repayable around £16,800 (about £1,800 in interest). That's a saving of roughly £1,400 against the personal loan and £2,100 against the secured loan over the full term.

So if you can get a further advance, the maths points toward it being the cheapest way to fund this specific renovation by a meaningful margin. That's a big "if", though, covered next.

Why is a further advance often cheapest, and why might I not get one?

A further advance tends to win on price because it's priced off mortgage-level risk rather than unsecured or second-charge lending risk, so the rate sits closer to what you're already paying on your main mortgage. That's exactly why it looks so attractive in the calculator above. The catch is availability. Your existing lender will reassess your loan-to-value, your income, and your credit record as if you were applying afresh, and if your equity has thinned or your circumstances have changed since you took out your mortgage, they can simply say no, or offer a rate well above their standard further-advance pricing. This is a genuine limitation of relying on the cheapest figure alone: it's the best result only for homeowners who actually qualify for it.

So before you plan your renovation budget around the further-advance figure, ring your lender and get an actual quote. Don't assume the cheapest number in the calculator is the one you'll be offered.

What does this calculator leave out?

The monthly payment and total cost figures above are based purely on the loan amount, term and rate you enter: they don't include arrangement fees, which secured loans and further advances commonly charge, sometimes running into several hundred pounds added to the loan or paid upfront. A personal loan is usually fee-free, which narrows the real-world gap between it and a further advance once fees are factored in. It's also worth working out what the renovation itself will realistically cost before you fix the loan amount. Our home improvement guide covers typical price ranges for kitchens, lofts and extensions, and the cost of ownership tracker can help you see how a new loan repayment sits alongside your other homeownership costs.

So treat every figure this tool gives you as before fees, and ask each lender for a full cost breakdown, including fees, before you compare final offers.

What this means for you

If you're renovating on a fixed budget and speed matters, a personal loan gets the work started fastest with no risk to your home directly. If you need to borrow more than an unsecured lender will offer, or want a longer term to keep payments manageable, a secured loan opens that door at a cost. But if you've built up equity and your existing lender will offer you a further advance, most people who run these numbers end up choosing it, because the rate gap over a 5-year term is rarely small enough to ignore. If you're in this position, the sensible sequence is: get a further-advance quote from your existing lender first, get a personal loan quote as a fallback, and only look at a secured loan if neither of those covers the amount you need. Check our full calculator library for related tools if you're also weighing up affordability alongside the renovation cost.