24/09/2026
Spray foam insulation installers never tell you at the point of sale that you may not be able to sell your home if you have it installed
When homeowners are then faced with this problem, the response they get and we have had, its rubbish you can get mortgages.
Couple of things there,
Firstly, it’s the buyer of the property who will have the issue gaining the mortgage.
Secondly, if as a seller you can persuad your buyer to try a different mortgage, no high street bank will loan and they will have to approach a specialist mortgage company, who normally loan on nonstandard build properties.
Comparing Mainstream vs. Specialist Rates
Because mainstream lenders reject properties with spray foam, you are forced to look at specialist lenders or regional building societies that use manual underwriting.
Mainstream Lenders (High Street) versus Specialist/Niche Lenders
Accepts Spray Foam?
Mainstream No (unless completely removed)
Niche Lenders Case by-Case (with strict conditions)
Typical Interest Rates
Mainstream Lower (Standard market rates)
Niche Lender Higher (Typically 3% above standard rates)
Required Deposit / Equity
Mainstream Standard (e.g., 5% to 10% minimum)
Niche Lender Often requires higher equity (e.g., 20% to 25% minimum)
Why Are the Rates Higher?
• Risk Premium: Lenders view spray foam as a high-risk feature because it can mask roof timber rot and severely impact the property's future saleability. To offset this risk, specialist lenders charge a premium on their interest rates.
• Lack of Competition: Only a small handful of secondary or specialist lenders will even consider a property with spray foam. Because there is very little competition in this space, these lenders do not need to cut their rates to win your business.
• Broker Fees: In addition to higher interest rates from the lender, specialist brokers often charge a broker fee (typically ranging from £495 to 1% of the loan amount) due to the extensive manual paperwork and negotiation required to get these deals approved.
The Alternative Strategy: Compare the Long-Term Cost
Before committing to a higher-rate specialist mortgage, it is highly recommended to do a cost-benefit analysis against the cost of removing the foam completely.
If you pay a specialist broker to find a niche lender, you might end up locked into a mortgage that costs you thousands of pounds extra in interest over a 2 or 5-year fixed term. Alternatively, paying to have the spray foam professionally removed and certified up front might allow you to qualify for a much cheaper, standard mortgage on the high street.
We offer a free survey with a quotation, to help you navigate through the issues with spray foam insulation, call us on 01252 750444 for free advice
