Finance Mixed-Use Property with a Semi-Commercial Mortgage

A semi-commercial mortgage is a single loan used to purchase or refinance a mixed-use property that contains both residential and commercial elements. The property may sit under one roof or span separate units within a single title. Unlike a standard residential mortgage or a pure commercial product, a semi-commercial mortgage covers the middle ground where both uses coexist under one financing arrangement.

The most common example in the UK is a shop with a flat above, but mixed-use properties take many forms. Pubs and restaurants with upstairs living quarters, office buildings with an attached residential unit, dental practices with a flat above the surgery, and guest houses with an owner's apartment all qualify. Even a converted barn split between a holiday let and a small workshop may fall under the semi-commercial umbrella.

Lenders classify a property as semi-commercial when between 40% and 50% of the floor space or value is residential. Below that threshold, most treat the property as fully commercial. Above it, some lenders may consider a standard buy-to-let mortgage instead, depending on their individual criteria and how the commercial element is used.

Semi-commercial mortgages suit property investors diversifying income across both residential and commercial tenants, business owners who want to live above or beside their premises, and landlords building mixed-use portfolios. Terms typically range from 1 to 25 years, with both interest-only and capital repayment structures available. Loan sizes start from around £50,000 with specialist lenders and can reach £25 million or more for larger mixed-use developments.

One practical benefit of purchasing mixed-use property is the stamp duty treatment. Transactions classified as non-residential or mixed-use attract lower SDLT rates than purely residential purchases, which can reduce your upfront costs by thousands of pounds on higher-value properties.

When you apply for a semi-commercial mortgage, the lender evaluates the property in two distinct parts. The residential portion is assessed using standard affordability methods: rental income (if let) stress-tested at a rate typically 1-2% above the pay rate, or personal income if you plan to live in the residential unit. The commercial portion is assessed based on the business's trading accounts, the commercial tenant's lease terms, and the tenant's covenant strength.

This dual assessment makes semi-commercial mortgages more complex than either a residential or fully commercial product. Lenders need to see that both income streams independently support the borrowing rather than relying on cross-subsidy between the two halves of the property.

A key point of variation between lenders is the residential-to-commercial split threshold. Some require at least 40% of the property to be residential before they classify it as semi-commercial. Others set this at 50%. A few specialist lenders are more flexible and assess properties with a smaller residential element on a case-by-case basis.

The split is usually calculated by floor area, though some lenders use value instead. For a shop with a flat above where the commercial unit occupies the ground floor and the flat spans two upper floors, the residential portion typically represents around 60-65% of total floor area, making it a straightforward semi-commercial case for most lenders. Where the split is close to 50/50, different lenders may classify the same property differently, making broker guidance valuable.

Lenders also consider the type of commercial use. Retail and office space is viewed more favourably than restaurants, takeaways, or licensed premises, which carry higher perceived risk. The length of commercial lease remaining matters too: a tenant locked into a 10-year lease provides more income certainty than one on a rolling monthly agreement.

Semi-commercial mortgage rates in mid-2026 typically range from 5.5% to 8.5%, depending on LTV, property type, borrower profile, and whether you choose a fixed or variable product. These rates sit between buy-to-let products (generally 4.5% to 6.5%) and pure commercial mortgages (often 5.0% to 9.0%), reflecting the blended risk profile lenders assign to mixed-use property. For a broader picture of where these sit in the market, see our guide to commercial mortgage rates.

Most semi-commercial mortgage lenders offer up to 75% LTV, meaning you need a minimum 25% deposit. Some specialist lenders stretch to 80% LTV for strong applications with standard property types, while others cap at 65% LTV for properties with a higher commercial weighting or for borrowers with adverse credit history.

Your semi-commercial mortgage deposit requirement depends heavily on the property and your circumstances. A straightforward shop with a flat above at 75% LTV on a £400,000 property requires a £100,000 deposit. At 65% LTV, that deposit rises to £140,000. If you have bad credit or the property is considered higher risk, such as a pub or restaurant, lenders may require 30-40% deposit.

Fixed-rate products of two to five years are the most common choice, providing payment certainty during the initial period. Tracker rates linked to the Bank of England base rate are available from some lenders and may start lower but carry the risk of increases. Variable rate products with lender-set rates are also offered but remain less popular due to their unpredictability.

Choosing the right mortgage type depends on the property and how you intend to use it. The distinction between a semi-commercial mortgage, a commercial mortgage, and a buy-to-let mortgage is not always obvious, particularly where the residential and commercial proportions sit close to a lender's classification threshold.

A pure commercial mortgage applies to properties used entirely for business purposes: offices, warehouses, retail units, or industrial premises with no residential element. A buy-to-let mortgage covers residential properties let to tenants without any commercial use. A semi-commercial mortgage covers the middle ground where both uses exist within a single property or title.

The practical differences extend beyond definition. Commercial mortgages typically require larger deposits of 25-40%, offer terms up to 25 years, and carry higher arrangement fees. Buy-to-let products usually offer the most competitive rates but cannot be used where any commercial activity takes place on the premises. Semi-commercial products blend elements of both, with rates and deposit requirements falling between the two.

One common mistake is assuming you can use a buy-to-let mortgage for a property with a small commercial element, such as a ground-floor unit that retains a commercial lease while the upper floors are residential. Most buy-to-let lenders will decline this application and require a semi-commercial product instead. Equally, if the property is primarily commercial with only a small caretaker flat, a fully commercial mortgage may be more appropriate and could offer better terms from specialist commercial lenders.

Understanding semi-commercial mortgage costs is easier with specific figures. Consider a shop with a two-bedroom flat above in a regional town centre, valued at £400,000.

At 70% LTV, you borrow £280,000 with a £120,000 deposit. Using a fixed rate of 6.25% over a 20-year term, here is how your monthly payments compare between the two main repayment structures.

Interest-only repayments: £280,000 multiplied by 6.25% divided by 12 equals £1,458 per month. You pay only the interest each month and must repay the full £280,000 capital at the end of the term, either by selling the property or refinancing.

Capital and interest repayments: approximately £2,048 per month. Over the full 20-year term, you repay the entire loan plus interest, totalling around £491,520. The total interest cost across the full term is £211,520.

If the commercial unit generates £1,200 per month in rent and the residential flat lets for £850 per month, your combined gross rental income is £2,050. On an interest-only basis, this covers the mortgage with £592 monthly headroom before expenses such as insurance, maintenance, and management fees. On a capital repayment basis, the rental income falls just short of the monthly payment, requiring a top-up from other income sources.

Lenders typically stress-test affordability at rates 1-2% above the pay rate. At a stress rate of 8.25%, the interest-only payment rises to £1,925 per month, still covered by the combined rental income but with less margin. Use a commercial mortgage calculator to model different scenarios for your specific property and borrowing amount.

Semi-commercial mortgage eligibility varies by lender, but several core criteria apply across the market. Understanding these before you apply helps you target the right lenders and avoid wasted applications that could affect your credit file.

• Personal income: most lenders require minimum personal income of £25,000 to £50,000 per year, though some specialist providers waive income requirements if the property's combined rental income adequately covers the mortgage at the stress-tested rate.
• Credit history: high-street lenders typically require a clean credit record with no defaults, CCJs, or missed payments in the last three to six years. Specialist lenders consider applicants with adverse credit, though you will face higher rates and lower maximum LTV.
• Business trading history: if the commercial element is owner-occupied, lenders want at least two years of trading accounts showing the business can sustain itself. For let commercial units, the focus shifts to the tenant's covenant strength and remaining lease term.
• Self-employed applicants: you can access semi-commercial mortgages as a self-employed borrower with SA302 forms or certified accounts for the last two to three years. Some lenders accept one year of accounts for established businesses with strong income.
• SPV and limited company purchases: many investors buy semi-commercial property through a special purpose vehicle. Not all lenders accept SPV applications, but those that do assess the company alongside personal guarantees from directors.
• Required documents: expect to provide proof of identity, three to six months of bank statements, business accounts or SA302s, details of existing property portfolios, a business plan for owner-occupied premises, and the property's commercial lease agreements.

The application process typically takes 6 to 12 weeks from initial enquiry to completion, longer than residential mortgages due to the complexity of dual valuations, commercial lease reviews, and more detailed underwriting requirements.

Stamp duty on semi-commercial property follows non-residential SDLT rates, which are significantly lower than the residential rates applied to standard buy-to-let or homeowner purchases. This difference produces meaningful savings, particularly on properties valued above £250,000 where the residential additional dwelling surcharge would otherwise apply.

The non-residential and mixed-use SDLT bands for England and Northern Ireland in 2025/26 are structured in three tiers. The first £150,000 is charged at 0%. The portion from £150,001 to £250,000 is charged at 2%. Everything above £250,000 is charged at 5%.

For a mixed-use property purchased at £400,000, the calculation works as follows: the first £150,000 at 0% costs nothing, the next £100,000 at 2% costs £2,000, and the remaining £150,000 at 5% costs £7,500. Total SDLT is £9,500. Compare this to a £400,000 residential investment property where buy-to-let stamp duty with the additional dwelling surcharge would exceed £27,500.

This means buying a mixed-use property can save over £18,000 in stamp duty compared to a purely residential investment at the same price. However, you cannot claim mixed-use SDLT treatment on a property that HMRC classifies as wholly residential. The property must genuinely contain a separate commercial element with an identifiable commercial use.

Scotland applies Land and Buildings Transaction Tax with different rate bands, and Wales uses Land Transaction Tax. Both jurisdictions have non-residential rate structures that offer similar advantages for genuine mixed-use purchases. Take professional advice on which regime applies to your specific transaction.

Buying semi-commercial property through a special purpose vehicle or limited company has become increasingly popular among UK property investors. An SPV is a limited company created specifically to hold property, keeping the investment ring-fenced from your other business activities and personal finances.

The main advantages of purchasing through an SPV include paying corporation tax on rental profits rather than personal income tax, the ability to offset mortgage interest in full against rental income (avoiding the Section 24 restriction that limits relief for personal buy-to-let limited company landlords), and easier portfolio management when holding multiple properties across different company structures.

However, not all semi-commercial mortgage lenders accept SPV applications. Those that do typically charge rates 0.25% to 0.75% above personal borrowing rates and may require personal guarantees from all company directors. Maximum LTV for SPV purchases is often 5-10% lower than for personal applicants, meaning you need a larger deposit.

Factor in the additional running costs of a limited company: annual accounts preparation, corporation tax returns, and Companies House filing fees. For a single semi-commercial property generating modest rental income, these costs can outweigh the tax benefits. For a portfolio of mixed-use properties or for higher-rate taxpayers, the structure often becomes significantly more tax-efficient over the medium to long term.

Seek specialist tax advice before deciding between personal and limited company ownership. The right structure depends on your wider income, existing property holdings, and long-term investment strategy.

Semi-commercial mortgages carry specific risks beyond standard residential lending that you should evaluate thoroughly before committing to a purchase or refinance.

• Void periods: commercial tenants can be harder to replace than residential tenants, particularly in secondary or tertiary locations. A vacant commercial unit means losing a significant portion of your rental income while mortgage payments continue. Budget for at least three to six months of commercial void periods when stress-testing your affordability.
• Commercial lease complexity: commercial leases operate differently from assured shorthold tenancies. Tenant break clauses, rent review mechanisms, and full repairing and insuring obligations can all affect your costs and net income. Have a commercial property solicitor review all leases before you exchange contracts.
• Valuation volatility: mixed-use property valuations are more subjective than residential valuations. Commercial values depend on rental yield and tenant covenant strength, so a weak tenant or a short remaining lease can significantly reduce the property's value and your ability to refinance at a competitive rate.
• Regulatory requirements: energy performance certificate requirements, licensing for certain commercial uses, and planning restrictions can all affect mixed-use properties. Minimum EPC ratings apply to both residential and commercial lettings in England and Wales, and failing to meet them can restrict your ability to let or renew leases.
• Exit strategy: lenders expect a clear exit plan, whether that is sale, a commercial remortgage, or full capital repayment. Properties in niche commercial sectors may be harder to sell, limiting your options at the end of the mortgage term and potentially leaving you unable to refinance on favourable terms.