A semi-commercial mortgage â also called a mixed-use mortgage â is a loan secured against a property that combines commercial and residential elements. The most common example is a retail unit or office on the ground floor with one or more residential flats above. The property is valued and financed as a single asset, but the income streams come from both commercial tenants and residential tenants.
This property type sits between the residential mortgage market and the commercial mortgage market, and it falls firmly into commercial mortgage territory. Standard residential mortgage lenders do not lend on semi-commercial property.
Why Semi-Commercial Is Treated as Commercial
The classification is driven by the commercial element. Once a property has a meaningful commercial component, it is assessed on commercial underwriting criteria â DSCR, commercial LTV limits, and specialist valuation â regardless of how much of the floor space or income is residential.
Most lenders treat a property as semi-commercial once the commercial floor space or rental income exceeds a threshold â commonly 20â40% commercial. Below that, some lenders may treat it as residential with a commercial element; above it, commercial underwriting applies. The threshold varies by lender and should be confirmed on a case-by-case basis.
Underwriting Semi-Commercial Property
Lenders assess semi-commercial mortgages on the combined income from both elements:
Commercial element: the passing rent from the commercial tenant, assessed against the lease length, tenant covenant (financial strength of the tenant), and market rental value. A long lease to a solvent trading business provides strong income support. A vacant unit or a tenant on a short lease creates uncertainty.
Residential element: rental income from the flats above, assessed similarly to buy-to-let underwriting â rental coverage against the debt attributable to the residential portion.
The combined DSCR must meet the lender’s minimum â typically 1.25x on the blended income. [EDITORIAL JUDGEMENT â verify against specialist lender criteria]
LTV: semi-commercial mortgages typically attract slightly lower LTV than standard residential buy-to-let, reflecting the additional complexity and the more limited resale market for mixed-use property. Indicative LTV: 65â75%, though this varies by lender and the specific mix of commercial and residential. [VERIFY â cross-reference Shawbrook, InterBay, Together criteria pages]
Which Lenders Offer Semi-Commercial Mortgages
High street banks are largely absent from this market. The complexity of valuing and underwriting mixed-use property, combined with the limited secondary market, means most high street lenders decline semi-commercial cases.
Specialist property lenders are the primary providers:
- Shawbrook Bank: strong semi-commercial appetite, experienced in mixed-use property across a range of configurations
- InterBay (OSB Group): specialist in commercial and semi-commercial investment, particularly for portfolio landlords
- Together Money: broad appetite for complex property including mixed use, including cases with adverse credit history
- Paragon Bank: experience with mixed residential/commercial portfolios
[VERIFY â confirm current appetite and criteria from each lender’s website before publication]
Valuation of Semi-Commercial Property
RICS valuers assess semi-commercial property using a hybrid approach â the residential flats are valued on a capital value basis (comparable sales); the commercial element is valued on an investment basis (yield applied to the passing rent or ERV). The two are combined into a single property valuation.
The commercial element’s valuation is sensitive to lease terms and tenant quality. A vacant ground floor unit reduces the valuation materially, even if the residential flats above are fully let.
Common Use Cases
Property investors buying mixed-use assets: a retail unit with flats above is a common investment property type in town centres. Semi-commercial mortgages finance these purchases.
Business owners who own the building: a business that occupies the commercial unit and owns the whole building (including residential flats above) may finance the whole property on a semi-commercial basis, using the residential rental income to supplement the commercial owner-occupier income.
Portfolio landlords adding commercial exposure: landlords with primarily residential portfolios sometimes add semi-commercial property for income diversification or because suitable property in their target area happens to be mixed use.
What Makes a Semi-Commercial Case Difficult
Vacant commercial unit: an empty ground floor unit removes the commercial income and raises the question of how quickly it will let. Lenders are cautious on vacancy and may require a lower LTV or a rent deposit.
Short commercial lease: a commercial lease with under 2â3 years remaining creates refinancing risk. The lender’s security depends on the income continuing; a lease expiry during the mortgage term is a concern.
Weak commercial tenant: a small, unprofitable, or recently-formed business in the commercial unit provides weak covenant. Institutional or well-established tenants are preferred.
Unusual commercial use: a pub, casino, or other licensed use in the commercial unit is treated as specialist and attracts even more limited lender appetite within the semi-commercial space.
Related Pages
- Commercial Investment Mortgages
- Commercial Mortgage Rates
- Commercial Mortgage LTV Explained
- DSCR Explained
- Best Commercial Mortgage Lenders UK