Can you claim SDLT relief if a buy-to-let property was in poor condition and not fit to live in?

Introduction

Many buyers ask whether Stamp Duty Land Tax (SDLT) can be reduced or reclaimed where a property was in very poor condition when purchased. This usually comes up where the buyer acquired a flat or house as an investment, found serious defects on completion, and then spent money putting the property right.

The key legal question is not whether the property needed work. It is whether, at the effective date of the transaction, the building was suitable for use as a dwelling. That test matters because a property that is not suitable for use as a dwelling may fall outside the residential SDLT rules.

This area has become harder for taxpayers after recent case law. In particular, the threshold for showing that a property was truly uninhabitable is now relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.

The Question

A buyer purchased a residential property as a buy-to-let investment. At the time of purchase, the property had a range of defects. These included serious drainage and waste-water problems, mould in the bathroom, a broken bathroom window, uneven flooring, poor electrics, and an ageing boiler. The buyer later carried out substantial works, including installing a new bathroom system, replacing sanitaryware, fitting a new boiler and heating system, installing a new kitchen, rewiring, replacing floor coverings, redecorating, carrying out external works, and arranging drainage repairs.

The issue is whether those facts are enough to show that the property was not suitable for use as a dwelling at the date of purchase, so that the SDLT treatment could be changed.

Nick’s Explanation

Nick’s explanation, in substance, is that the evidence needs to focus on the condition of the property at the time of purchase and whether the defects made normal residential occupation impossible, not merely inconvenient or unattractive.

In anonymised form, his reasoning can be summarised like this:

“The important point is the state of the property on completion. A property does not become non-residential just because it was dated, needed major refurbishment, or required replacement of kitchens, bathrooms, boilers, wiring or floor finishes. The defects must go further and show that it was not suitable for use as a dwelling at that point.”

He also focused on the practical evidence that would matter, such as invoices and records of the remedial works, but those documents only help if they prove the original condition and show that the defects were serious enough to prevent ordinary habitation.

The strongest points in this scenario are the reported sewage and waste-water backflow issues and the blocked drainage. Those defects may support an argument that the property lacked basic sanitary functionality. But the wider list of works, taken on its own, also includes many items that often appear in ordinary refurbishment projects and do not by themselves prove legal uninhabitability.

The Law

SDLT is charged under the Finance Act 2003. Whether a property is taxed as residential depends in part on whether, at the effective date of the transaction, it consists of or includes a building that is used or suitable for use as a dwelling.

The residential definition is found in section 116 of the Finance Act 2003. Broadly, a building counts as residential property if it is used or suitable for use as a dwelling, or is in the process of being constructed or adapted for such use.

The case law has established that suitability for use as a dwelling is assessed objectively as at the effective date of the transaction, usually completion. The question is not what the buyer intended to do with it, how much money was spent afterwards, or whether the property was a good investment. The question is whether the building, in its actual state at that time, was suitable for residential occupation.

The authorities have repeatedly shown that this is a strict test. A property can still be “suitable for use as a dwelling” even if it is run-down, unpleasant, in disrepair, or in need of substantial renovation.

Most importantly, in Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, the Court of Appeal confirmed that the threshold is relatively high. Serious disrepair does not automatically make a property unsuitable for use as a dwelling. The court’s approach reinforces that only significant defects going to the basic functionality of the dwelling are likely to take it outside the residential rules.

Analysis

The correct way to analyse this type of case is step by step.

First, identify the legal test. The issue is whether the property was suitable for use as a dwelling on the completion date. It is not enough that it was in poor condition, difficult to let, or in need of refurbishment.

Second, separate core habitability defects from ordinary renovation items.

• Core habitability points here include sewage backing up into the kitchen sink, bathroom waste-water backing up into the bath, and heavy mould.
• Ordinary renovation items include replacing the kitchen, replacing floor coverings, redecorating, external painting, rendering, and even replacing an old boiler unless it had actually failed and left the property without usable heating or hot water.

Third, ask whether the serious defects prevented normal occupation in a real and practical sense. Drainage failures can be important because a dwelling ordinarily needs functioning sanitation. If using the bathroom caused backflow into the bath, and blocked drains caused sewage to back up into the kitchen sink, that points toward a potentially serious loss of basic amenity. However, the evidence would need to show that this was an actual and substantial condition at the relevant date, not a temporary inconvenience or a problem that could be managed pending repair.

Fourth, consider the effect of the post-purchase works. Extensive works do not prove the legal test by themselves. Buyers often install a new bathroom, a new kitchen, new electrics and new flooring in a property that was still legally a dwelling when bought. HMRC and the courts usually look past the scale of expenditure and focus instead on whether the property had the essential characteristics of a dwelling at completion.

Fifth, apply the current high threshold. After Mudan, a taxpayer needs strong evidence that the defects were so fundamental that the building was not suitable for residential use at all. In practice, successful cases tend to involve very serious problems affecting essentials such as sanitation, water, structural integrity, or other basic features required for habitation.

On these facts, the drainage and sewage issues are the most significant aspects of the case. They are more helpful than the mould, uneven flooring, broken window, dated boiler, or poor decorative condition. But even then, the overall position is not straightforward. A tribunal or HMRC would likely ask:

• Was there a functioning toilet, sink and bath or shower at completion?
• Were the drainage failures constant and severe, or intermittent?
• Was the property capable of being occupied safely, even if not comfortably?
• Is there independent evidence from contractors, surveyors, photographs or reports showing the true condition at the purchase date?
• Did the buyer actually acquire a dwelling in need of renovation rather than something that had ceased to be suitable as a dwelling?

Without strong contemporaneous evidence, HMRC would be likely to say that this was a residential property in poor repair, not a non-residential one.

Outcome

The practical conclusion is that a poor-condition buy-to-let property will not usually fall outside the residential SDLT rules just because it needed major works. In this scenario, the best argument would rest on the sewage and drainage defects, because those go to basic sanitation. Even so, the threshold is now relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, so the case would need clear and persuasive evidence that the property was genuinely not suitable for use as a dwelling on completion.

If the evidence only shows serious disrepair and substantial refurbishment, rather than true unsuitability for habitation, the property is likely to remain residential for SDLT purposes.

Practical Steps

If you are assessing a similar case, the sensible next steps are:

• Gather contemporaneous photographs showing the condition at or very close to completion.
• Obtain survey reports, contractor reports, drainage reports, and invoices that describe the original defects in detail.
• Focus on evidence about sanitation, water, drainage, electricity, heating, and safety rather than general refurbishment.
• Create a timeline showing exactly what was wrong on completion and when each defect was fixed.
• Check whether the boiler, drainage and sanitary systems were actually unusable, rather than simply old or defective.
• Review the purchase documents, valuation material, and any lender or surveyor comments about habitability.
• Compare the facts carefully against the modern case law, especially the stricter approach confirmed in Mudan.

Conclusion

A property is not taken out of the residential SDLT rules merely because it was run-down and required major renovation. The question is whether it was suitable for use as a dwelling at completion. Where the main problems are refurbishment-related, the answer will usually still be yes. Only genuinely fundamental defects, supported by strong evidence, are likely to meet the now relatively high threshold for uninhabitability.

Legal References Used

• Finance Act 2003, section 116
• Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799

This page was last updated on 22 March 2026.

See all questions and answers categorized in this sitemap. Or use Google site search below.