How Do You Finance a Loft Conversion or Extension?

A loft conversion or extension is one of the smartest investments you can make in your home. It adds space, adds value, and costs far less than moving house. The part that stops most homeowners in their tracks is not the build itself. It is working out how to fund it.

The information contained on this blog is for educational and informational purposes only and is not intended to address your particular personal needs. It is not, and should not be considered, financial advice or a recommendation. You should consult with a professional to determine what may be best for your individual needs.

A loft conversion or extension is one of the smartest investments you can make in your home. It adds space, adds value, and costs far less than moving house. The part that stops most homeowners in their tracks is not the build itself. It is working out how to fund it.

Here is a plain-English breakdown of every realistic option available to you in 2026.

What This Guide Covers:

• What these projects actually cost
• Using your savings
• Personal loans
• Remortgaging
• Further advances
• Secured loans
• Credit cards
• Which option suits which situation

What Does the Work Actually Cost?

You need a real number before you can choose a finance route.

According to the Federation of Master Builders, a single-storey extension costs between £1,800 and £3,000 per square metre in 2026. A 20m² extension typically runs between £36,000 and £60,000 depending on specification, excluding professional fees and contingency.

Loft conversions range from around £55,000 to £120,000 depending on conversion type. Velux conversions sit at the lower end. Full dormer or hip-to-gable conversions sit at the higher end.

Get a fixed-price quote before you decide how much to borrow. An estimate is not good enough at this stage.

Using Your Own Savings

No interest. No debt. No approval process. If your savings cover the full cost, this is almost always the right choice.

The drawback is timing. Building costs can rise while you save, and a project that costs £45,000 today may cost more in two years. If you have most of the funds but not all, combining savings with a smaller loan is worth considering rather than borrowing the full amount.

Personal Loans and Home Improvement Loans

A personal loan is the most straightforward borrowing route for projects up to around £25,000 to £35,000. You borrow a fixed amount and repay it in fixed monthly instalments over an agreed term, typically two to seven years.

The Bank of England base rate currently stands at 3.75% following a cut in December 2025. Representative APRs on personal loans vary depending on the lender and your credit profile. Most mainstream lenders cap unsecured personal loans at £25,000, though some go higher.

Personal loans are unsecured, meaning your home is not at risk if you miss payments. Your credit rating is, however, and missed payments affect future borrowing.

This option suits smaller projects or situations where savings cover most of the cost and you need to bridge a gap.

Remortgaging

Remortgaging means taking out a new mortgage larger than your current one. The difference is released to you as a lump sum to fund the work.

Mortgage rates are generally lower than personal loan rates, making this one of the more cost-effective routes for larger projects. It suits homeowners who have built up meaningful equity, are at or near the end of their current fixed term, and need to borrow a sum that exceeds what a personal loan can provide.

Check early repayment charges on your existing deal before proceeding. Also consider whether extending your mortgage term increases your total repayment cost, even if the monthly payment looks lower.

Further Advance

A further advance lets you borrow additional money from your existing mortgage lender without switching providers. The process is simpler than a full remortgage and often involves lower fees.

The rate applied to the additional borrowing may differ from your current mortgage rate, so check the cost carefully. This suits homeowners who want to avoid switching lenders and have enough equity to support the additional borrowing.

Secured Loans

A secured loan sits alongside your existing mortgage rather than replacing it. Because your home is used as collateral, secured loans typically carry lower interest rates than unsecured personal loans and allow you to borrow larger sums.

The trade-off is that your property is at risk if you miss repayments. The application process also takes longer because the lender needs to assess your property.

This is worth considering where remortgaging is not practical due to high early repayment charges and you need to borrow more than a personal loan permits.

Credit Cards

Credit cards are not a realistic way to fund an extension or loft conversion in full. They are useful for covering smaller costs during the build, such as fixtures, fittings or decoration, particularly on a 0% purchase deal.

The discipline required is clearing the balance before the 0% period ends. Revert rates on credit cards are typically far higher than any other borrowing option.

Which Option is Right for You?

The right route depends on how much equity you hold, your current mortgage terms, your credit profile, and the total project cost.

As a general guide: use savings first if available. Use a personal loan for smaller gaps up to around £25,000. Remortgage or take a further advance for larger projects where you have equity and are not tied into costly early repayment charges. Consider a secured loan where remortgaging is not practical but you need to borrow a larger sum.

Whatever route you take, get your fixed-price quote first. Knowing the exact figure makes every conversation with a lender far more straightforward.

Your Next Steps

Use Your Space works with homeowners across Solihull, Warwick, Knowle, Dorridge, Bentley Heath, Shirley, Balsall Common, Leamington Spa and Kenilworth to deliver extensions and loft conversions properly, on budget and on time.

Contact Use Your Space today for a detailed fixed-price quote you can take straight to your lender.