Can a dangerous gas appliance make a property uninhabitable for SDLT purposes?

Introduction

Buyers sometimes ask whether a defect discovered shortly after completion means the property was not suitable for use as a dwelling when it was bought. This matters because, in some cases, a property that is not suitable for use as a dwelling may fall outside the normal residential SDLT rules.

A common example is where a gas safety inspection finds that a gas fire, boiler or other appliance is dangerous and must be disconnected. The key question is whether that defect is serious enough to mean the property itself was not suitable for use as a dwelling at the effective date of the transaction.

The short answer is that a single dangerous gas appliance will usually not be enough on its own. The legal threshold is now relatively high following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799.

The Question

A buyer purchased a buy-to-let property and, before letting it out, obtained a gas safety inspection. The engineer found that one gas appliance was dangerous, showing signs of spillage, and capped it off as immediately unsafe to use. The buyer wanted to know whether that issue could mean the property was uninhabitable at the date of purchase for SDLT purposes.

The buyer had also previously considered whether there might be any SDLT implications connected with Sharia-compliant property finance, but the immediate question was whether the condition of the property could support an SDLT claim based on unsuitability for use as a dwelling.

Nick’s Explanation

Nick’s view was that the position on uninhabitable property claims has become much stricter. In anonymised form, his explanation was that a property used to have a better chance of being treated as unsuitable for use as a dwelling where it was dangerous to live in and needed more than basic repairs. However, that route has narrowed significantly.

He explained that the present approach focuses on very serious defects and that buyers should gather evidence of the condition at the time of purchase, especially where the property was unsafe to live in and required major works. He also noted that, where Islamic finance structures are involved, SDLT treatment can be more complex because certain alternative finance arrangements have their own statutory rules.

Applied to a dangerous gas appliance, the underlying point is that the defect must relate to the dwelling’s overall suitability for residential use, not merely to one item that can be isolated, capped off or repaired.

The Law

SDLT is charged under the Finance Act 2003. Whether property is residential depends in part on whether it is “used or suitable for use as a dwelling” or is in the process of being constructed or adapted for such use.

The leading modern authorities on suitability for use as a dwelling include:

• PN Bewley Ltd v HMRC [2019] UKUT 65 (TCC)
• Mudan & another v HMRC, culminating in Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799

These cases show that the test is applied to the property at the effective date of the transaction. The issue is not whether the buyer intended to renovate it, nor whether it had defects, but whether it was objectively suitable for use as a dwelling at that time.

Following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, the condition threshold is now relatively high. Ordinary disrepair, missing items, outdated services, health and safety concerns that can be remedied, or defects that make occupation inconvenient or temporarily unsafe will not usually be enough. The courts have moved away from a broad reading of “unsuitable” and towards a stricter approach.

Where Sharia-compliant finance is involved, SDLT may also engage the alternative property finance provisions in the Finance Act 2003. Those rules can apply to certain purchase and resale, or lease-based, structures used by Islamic finance providers. The exact outcome depends on the structure used.

Analysis

The issue should be analysed in stages.

1. Identify the condition of the property at completion

   The relevant date is the effective date of the transaction, usually completion. Evidence created shortly afterwards, such as a gas safety record, can still be useful if it reflects the condition at that date.

2. Ask whether the defect affects the dwelling as a whole

   A dangerous gas fire is serious from a safety perspective, but SDLT does not ask simply whether one feature is dangerous. It asks whether the property was suitable for use as a dwelling. If the unsafe appliance can be capped off and the property can still be occupied using other heating or hot water arrangements, that points away from unsuitability.

3. Consider whether the defect is remediable

   If the problem can be fixed by replacing or repairing the appliance, that is usually a strong sign that the property remains a dwelling, albeit one in need of repair. The current case law draws a clear distinction between serious but remediable defects and defects so fundamental that the property cannot realistically function as a dwelling.

4. Assess the practical effect on occupation

   If the capped appliance was an optional gas fire in a room, rather than the only source of heating or an essential service affecting the whole property, it is unlikely to make the entire property unsuitable for use as a dwelling. Even if the appliance was immediately dangerous, the fact it could be isolated may mean the danger was confined rather than fatal to residential use.

5. Apply the higher threshold after Mudan

   Following Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, the bar is now relatively high. A buyer generally needs something much more fundamental than a defective appliance: for example, structural failure, extreme contamination, or the absence of basic features in a way that means the building cannot realistically be lived in as a dwelling at all.

On these facts, a gas engineer’s decision to cap off one dangerous gas fire would usually be treated as evidence of a repair issue, not evidence that the property itself ceased to be a dwelling for SDLT purposes.

Outcome

In most cases, no. A dangerous gas appliance on its own is unlikely to make a property uninhabitable for SDLT purposes.

That is especially so where:

• the defect affects only one appliance rather than the whole property;
• the appliance can be disconnected or isolated;
• the defect can be remedied by repair or replacement; and
• the rest of the property remains capable of normal residential occupation.

Given the current legal position, a claim based solely on a capped dangerous gas fire would be unlikely to succeed.

Practical Steps

If a buyer wants to assess whether a property may genuinely have been unsuitable for use as a dwelling at purchase, the following steps are sensible:

• collect all contemporaneous evidence, including survey reports, safety certificates, photographs, contractor reports and completion documents;
• identify whether the defect existed at completion, not just later;
• consider whether the issue affected the whole dwelling or only one part of it;
• ask whether the defect was readily repairable or whether it was fundamental;
• review whether the property lacked essential living facilities altogether, such as sanitation, safe structure, water or basic habitability;
• if Islamic finance was used, check the exact finance structure and whether the alternative property finance rules may be relevant separately from any condition issue.

If the evidence shows only isolated disrepair or a dangerous but replaceable appliance, the safer view is usually that the property remained residential for SDLT purposes.

Conclusion

A dangerous gas fire is an important safety issue, but it will not usually be enough to show that a property was not suitable for use as a dwelling when purchased. After Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799, the threshold for an uninhabitable or unsuitable-for-use argument is relatively high. Buyers generally need evidence of a much more fundamental defect affecting the dwelling as a whole.

Legal References Used

• Finance Act 2003
• PN Bewley Ltd v HMRC [2019] UKUT 65 (TCC)
• Amarjeet and Tajinder Mudan v The Commissioners for HMRC [2025] EWCA Civ 799
• Finance Act 2003 provisions relating to alternative property finance

This page was last updated on 22 March 2026.

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