Can an uninhabitable property be treated as non-residential for SDLT?

Introduction

Buyers sometimes ask whether a dwelling in very poor condition can be taxed at non-residential Stamp Duty Land Tax (SDLT) rates rather than residential rates. This usually comes up where the property has serious defects, health and safety hazards, or cannot realistically be lived in at the date of purchase.

The issue matters because the SDLT difference can be significant. It also affects whether the 3% higher rates for additional dwellings apply. But the legal test is strict, and recent case law has made clear that the threshold for showing a property is not suitable for use as a dwelling is now relatively high.

The Question

A buyer was purchasing a large residential property with serious condition problems. A housing hazards survey was obtained and identified a number of issues that might amount to Category 1 or Category 2 hazards under the Housing Health and Safety Rating System.

The buyer wanted to know whether, because of the condition of the property at completion, it could be self-assessed for SDLT as non-residential rather than residential. A further concern was that the buyer still owned a previous home at the time of purchase, so if the property had to be treated as residential, the 3% higher rates for additional dwellings might also apply, subject to a later refund if the previous main residence was sold in time.

Nick’s Explanation

Nick’s core point was that SDLT is a self-assessed tax, so the purchaser is responsible for the position taken on the return. In anonymised form, his explanation was that if a buyer chose to assess a property as non-residential because of its condition, that argument would depend on the property having hazards serious enough to make it uninhabitable at the effective date of the transaction.

He explained that an HHSRS survey may help identify serious hazards and may support an argument that the local authority could, in principle, take action under sections 20 or 21 of the Housing Act 2004 by making a prohibition order restricting use of the property as a dwelling.

He also noted the practical SDLT consequences:

• HMRC can open an enquiry into an SDLT return within the applicable enquiry window.
• If HMRC rejects the non-residential treatment, it may assess residential SDLT instead.
• If the buyer owned another dwelling at completion, HMRC may also seek the 3% higher rates.
• If the purchase is ultimately treated as residential and the previous main residence is sold within the statutory time limit, the buyer may then be able to claim a refund of the 3% higher rates.

The Law

SDLT is charged under the Finance Act 2003. Whether residential or non-residential rates apply depends on the nature of the property at the effective date of the transaction.

In broad terms, a building is 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 key question in poor-condition cases is often whether the building was still “suitable for use as a dwelling” at completion.

That test has been considered in a number of SDLT cases. The courts have repeatedly said that the issue is not whether the property is attractive, modern, mortgageable, or immediately comfortable to occupy. The question is whether it remains suitable for use as a dwelling in the ordinary sense at the relevant date.

Where a buyer argues that the building was not suitable for use as a dwelling because of disrepair or hazards, the evidence must show more than inconvenience, dated condition, or the need for substantial works. The condition must be serious enough to take the property outside the category of residential property for SDLT purposes.

Housing Act 2004 provisions can be relevant to the evidence. Under sections 20 and 21, a local housing authority may make a prohibition order in appropriate cases where serious hazards exist. That may be part of the factual picture, but the mere possibility that a local authority could act is not automatically enough on its own to change the SDLT classification.

In an uninhabitable or “not suitable for use” case, the condition threshold is now relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.

Analysis

The analysis usually works in five stages.

1. Identify the property’s condition at the effective date

   The relevant date is normally completion. Evidence should focus on the actual condition then, not on later works or later deterioration.

2. Ask whether the property was still suitable for use as a dwelling

   This is the central SDLT question. Serious defects may help, but many defective or run-down homes are still treated as residential. The threshold is not simply whether the property needed renovation or whether a survey found hazards.

3. Consider the strength of the evidence

   An HHSRS report may be relevant. So may photographs, contractor reports, structural reports, utility status, and evidence about sanitation, water, electricity, heating, weatherproofing, safety, and legal restrictions on occupation. However, evidence must go to actual suitability for use as a dwelling, not just poor condition.

4. Consider whether there was any genuine legal restriction on residential use

   If a prohibition order was actually in force at the effective date, that may be highly relevant. If there was no order, an argument based only on the idea that one could theoretically have been made is weaker. The existence of serious hazards does not automatically mean the property was non-residential for SDLT.

5. Check the higher rates position separately

   If the property is residential and the buyer owned another dwelling at completion, the 3% higher rates may apply. If the previous main residence is sold within the statutory period, a refund may be available. If the property is genuinely non-residential, the 3% higher rates do not apply.

Applying those principles, a buyer may have an arguable case where the defects were extreme and well evidenced. But after Mudan, the courts are likely to scrutinise such claims closely. A hazardous-condition argument is no longer enough unless the facts clearly show that the building had crossed the line from a dwelling in disrepair to something not suitable for use as a dwelling at all.

Outcome

A property is not treated as non-residential for SDLT just because it is in poor condition or requires major works. The buyer would need strong evidence that, at completion, it was not suitable for use as a dwelling. That is now a demanding test, and the threshold is relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.

If HMRC disagrees with a non-residential self-assessment, it may seek residential SDLT instead, and where relevant it may also seek the 3% higher rates. If the purchase is ultimately treated as residential and the previous main residence is sold within the required period, a refund of the 3% higher rates may be available.

Practical Steps

• Review the property’s actual condition at the completion date, not after renovation began.
• Gather contemporaneous evidence such as surveys, photographs, contractor reports, and any local authority documents.
• Check whether there was any formal prohibition order or other legal restriction in force at the effective date.
• Assess whether the evidence really shows the property was not suitable for use as a dwelling, rather than simply in serious disrepair.
• Consider the separate position on the 3% higher rates if another dwelling was owned at completion.
• If residential rates are paid including the 3% surcharge, check whether a later refund claim can be made after sale of the previous main residence.

Conclusion

A severely defective house is not automatically non-residential for SDLT. The legal question is whether it was suitable for use as a dwelling at completion, and that is now a high bar in poor-condition cases. Hazard reports may assist, but they are only part of the picture. Buyers should assess the evidence carefully before treating a property as non-residential.

Legal References Used

• Finance Act 2003
• Housing Act 2004, sections 20 and 21
• Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799
• HMRC guidance on repayment of the higher rates for additional dwellings

This page was last updated on 22 March 2026.

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