Can you pay less SDLT if the house you are buying is uninhabitable?

Introduction

Many buyers ask whether Stamp Duty Land Tax (SDLT) can be reduced if the property they are buying is in very poor condition. This usually comes up where the buyer believes the house is not fit to live in at completion and wants to know whether it can be treated as non-residential, or otherwise taxed more favourably.

This is an important question because the SDLT difference can be large. But the legal test is now strict. In particular, the Court of Appeal has confirmed that the threshold for showing a dwelling is not suitable for use as a dwelling is relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.

The Question

A buyer is purchasing a house and expects a substantial SDLT bill. The buyer believes the property is uninhabitable at the point of purchase and wants to know whether that condition could reduce the SDLT payable.

Nick’s Explanation

Nick’s explanation, put into general terms, is that calling a property “uninhabitable” is not enough by itself. The real legal question is whether, on the effective date of the transaction, the property was a “dwelling” for SDLT purposes.

His reasoning can be summarised like this:

• SDLT treatment depends on the property’s actual condition at the relevant date.
• A house can still count as a dwelling even if it needs major repair, refurbishment or modernisation.
• The test is demanding. Serious disrepair does not automatically mean the building is no longer suitable for use as a dwelling.
• After Mudan, only genuinely severe cases are likely to fall outside residential treatment.

In short, the issue is not whether the property is unpleasant, dated, or expensive to fix. The issue is whether its condition is so serious that it is not suitable for use as a dwelling at all.

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 or non-residential property.

For SDLT purposes, residential property includes a building that is used or suitable for use as a dwelling, or is in the process of being constructed or adapted for such use. The question is usually tested at the effective date of the transaction, which is commonly completion.

If a building is suitable for use as a dwelling on that date, the residential SDLT rules normally apply. If it is not suitable for use as a dwelling, the buyer may argue that the purchase is not of residential property in the ordinary sense, which can affect the SDLT rate structure.

The difficulty is that “not suitable for use as a dwelling” is interpreted narrowly. The courts have consistently treated many defective or run-down homes as still being dwellings. Missing items, disrepair, age, poor decorative condition, and the need for substantial works do not necessarily prevent a property from remaining residential for SDLT.

The current position has been reinforced by Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, which makes clear that the condition threshold is now relatively high in uninhabitable or unsuitable-for-use cases.

Analysis

When considering whether a property in bad condition might attract lower SDLT, the analysis usually works in stages.

First, identify the exact state of the property at completion. The relevant question is not what the buyer plans to do after purchase, and not whether the lender, surveyor or estate agent used the word “uninhabitable” in a loose sense. The focus is the property’s objective condition on the effective date.

Second, ask whether the building still has the character of a dwelling. A property may still be a dwelling even where it has:

• old or damaged kitchens or bathrooms
• damp, leaks or defective plaster
• unsafe electrics requiring replacement
• heating defects
• broken windows or poor insulation
• a need for extensive renovation before comfortable occupation

Third, consider whether the defects are so fundamental that the property is not suitable for use as a dwelling at all. This is where the threshold is now high. The question is not whether a reasonable buyer would want to move in immediately, but whether the building has crossed the line from a damaged dwelling into something no longer suitable for residential use.

Fourth, look at evidence. A successful argument usually needs strong contemporaneous material, such as:

• a survey describing the condition in detail
• dated photographs from around completion
• contract documents and auction particulars
• evidence of key missing or failed services
• local authority notices, if any
• contractor reports showing the nature and extent of the defects

Fifth, apply the stricter post-Mudan approach. Following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, the courts are unlikely to accept an “unsuitable for use” argument unless the facts are genuinely extreme. It is no longer enough simply to show that the property needed heavy refurbishment or could not realistically be occupied without works. The condition must be serious enough to take it outside the normal concept of a dwelling.

This means many claims based on missing kitchens, missing bathrooms, defective services, or major disrepair will now face difficulty unless the evidence shows a much more serious level of unusability.

Outcome

The practical answer is that a buyer should not assume SDLT can be reduced merely because a house is in poor condition or described as uninhabitable. In most cases, a run-down house will still be treated as residential property for SDLT.

Only in a limited category of severe cases will the property fail the dwelling test. After Mudan, that category is narrower than many buyers expect.

Practical Steps

If you are assessing this issue, the sensible next steps are:

1. Obtain the survey, valuation and any contractor reports that existed at or near completion.
2. Gather dated photographs showing the true condition of the property on the effective date.
3. Identify exactly which essential features were absent or unusable, and whether that position existed at completion.
4. Compare the facts against the current case law, especially Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.
5. Check whether the SDLT return has already been filed and, if so, whether any amendment or claim is still within time.
6. Take specific legal or tax advice before assuming the property qualifies for non-residential treatment or before making a repayment claim.

Conclusion

A house in bad condition is not automatically outside the residential SDLT rules. The legal test is whether it was suitable for use as a dwelling at completion, and that is now a high threshold to defeat. Following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, only genuinely severe cases are likely to succeed.

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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