Can you claim non-residential or mixed-use SDLT rates for a dwelling with a boatyard or similar commercial land?

Introduction

Buyers often ask whether Stamp Duty Land Tax (SDLT) can be reduced where a purchase includes a house together with land or features that look commercial, such as a yard, mooring area, workshop space or boat-related facilities. The issue usually turns on whether the property was entirely residential at the effective date of the transaction, or whether part of it was genuinely non-residential or mixed-use.

This question matters because mixed-use or non-residential treatment can produce a much lower SDLT charge than the residential rates. But the legal test is fact-sensitive, and the courts have taken a careful approach to claims that land attached to a dwelling should be treated as non-residential.

The Question

A buyer acquired a property that included a dwelling and adjoining land connected with boatyard-style use. The buyer wanted to know whether the purchase could properly be treated as mixed-use or non-residential for SDLT purposes, rather than as an ordinary residential purchase.

The material provided for review included photographs, video and supporting documents about the property and its surrounding land. The key issue was whether the non-dwelling elements were enough to change the SDLT treatment of the whole acquisition.

Nick’s Explanation

Nick confirmed that he had reviewed the material and had started preparing the case arguments. In anonymised form, his position was that the analysis would depend on the evidence showing the character and use of the land at the relevant date, rather than on labels or marketing descriptions alone.

The practical point in his response was that the claim would need to be built around the facts shown in the documents and imagery. In cases like this, the important question is not simply whether the property has unusual features, but whether part of what was bought was genuinely non-residential in law.

The Law

The starting point is the Finance Act 2003. SDLT applies differently depending on whether the subject matter of the transaction is residential property, non-residential property, or a mixture of the two.

Broadly:

• Residential property includes a building used or suitable for use as a dwelling, and land that forms part of the garden or grounds of that dwelling.
• Non-residential property includes commercial property and land that is not part of the garden or grounds of a dwelling.
• If a transaction includes both residential and non-residential property, it is generally treated as mixed-use and taxed at non-residential SDLT rates.

In practice, many disputes turn on whether land attached to a house is part of its “garden or grounds”. If it is, the whole purchase may still be residential even if the land is extensive or has unusual features. If it is not, mixed-use treatment may be available.

Where a taxpayer argues that a dwelling was not suitable for use as a dwelling at the effective date, the test is now demanding. In an uninhabitable or not suitable for use case, the condition thresholds are now relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799. Ordinary disrepair, dated condition or the need for renovation will often not be enough.

Analysis

The SDLT position in a dwelling-plus-boatyard scenario usually needs to be worked through in stages.

First, identify exactly what was bought. That means looking at the transfer plan, title documents, sales particulars, photographs, valuation evidence and any planning or licensing material. The legal analysis depends on the land included in the transaction, not just on how the property was described by the seller or agent.

Second, decide whether there was a dwelling on the property at the effective date of the transaction. If there was a building used or suitable for use as a dwelling, that points toward residential treatment unless another part of the property was genuinely non-residential.

Third, consider whether the surrounding land formed part of the garden or grounds of the dwelling. This is often the central issue. Land can still be “grounds” even if it is large, open, functional, or not landscaped like a garden. The question is whether it belongs with the dwelling in a real sense, having regard to layout, use, function and relationship to the house.

Fourth, test whether any part of the land had a separate and genuine non-residential use at the relevant date. In a boatyard-type case, this might include evidence of active commercial use, separate business operations, income-producing activity, dedicated yard space, operational structures, access arrangements, or treatment inconsistent with ordinary residential enjoyment of the dwelling.

Fifth, distinguish between historic use and current use. It is not enough that land was once used commercially. The relevant question is what the property was at the effective date of the transaction. A former boatyard that had effectively become part of the residential setting may still be treated as residential.

Sixth, consider whether the evidence shows a true mixed-use acquisition. If the commercial or non-residential element is real and forms part of the transaction, mixed-use rates may apply. If the alleged non-residential element is merely incidental to the dwelling, or still forms part of its grounds, HMRC is likely to argue that the whole purchase remains residential.

Finally, if the argument is instead that the dwelling was not suitable for use as a dwelling, that is a separate route and should not be confused with mixed-use analysis. Following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, the threshold for showing that a building was not suitable for use as a dwelling is relatively high. Serious structural or functional defects may be needed. Mere modernisation needs, poor condition, or incomplete refurbishment are unlikely to be sufficient.

Outcome

The practical conclusion is that a purchase of a dwelling with adjoining boatyard-style land is not automatically mixed-use. The buyer must be able to show that part of the property was genuinely non-residential at the effective date and was not simply part of the dwelling’s garden or grounds.

If the evidence supports a distinct non-residential element, mixed-use SDLT treatment may be available. If not, the transaction is likely to remain residential. And if the argument depends on the dwelling being uninhabitable, the current legal threshold is relatively high after Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.

Practical Steps

• Obtain the transfer, title plan and contract pack to confirm exactly what land was acquired.
• Gather contemporaneous evidence from the purchase date, including photographs, video, surveys, planning material and valuation evidence.
• Identify any actual commercial or operational use of the land at the effective date, not merely historic use.
• Check whether any part of the land had separate access, separate facilities, separate income-producing use, or a function independent of the dwelling.
• Review whether the land is more likely to be characterised as the garden or grounds of the dwelling.
• If arguing unsuitability for use as a dwelling, assess the condition evidence against the stricter standard now reflected in Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.
• Prepare a fact-based legal analysis rather than relying on estate agent descriptions or assumptions about what “looks commercial”.

Conclusion

A house with a yard, mooring area or boat-related land does not automatically qualify for mixed-use SDLT treatment. The real question is whether, on the facts at the transaction date, part of the property was truly non-residential and not part of the dwelling’s grounds. Where the argument is based on habitability, the current legal threshold is high.

Legal References Used

• Finance Act 2003
• Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799

This page was last updated on 22 March 2026.

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