Stamp Duty on a Barn Conversion
Whether you pay residential or non-residential stamp duty on a barn depends on what is physically there on the day you complete. Planning permission alone does not change the answer. Conversion work that has already started does.
Key Takeaways
- An unconverted barn is non-residential property. In England and Northern Ireland the rates are 0% up to £150,000, 2% to £250,000 and 5% above
- Planning permission, including Class Q approval, does not make a barn residential on its own. HMRC says conversion work must be physically under way at completion (SDLTM00400)
- Once conversion work has physically started, the barn is a building "in the process of being constructed or adapted" for use as a dwelling, so residential rates apply
- An unconverted barn is not a dwelling, so there is no 5% surcharge, no first-time buyer relief and no 17% company rate on it
- A barn in the garden or grounds of a house you are buying is residential along with the house. Barns and farmland in separate commercial use can make a purchase mixed
- The classification is fixed on the effective date, usually completion. Work you start afterwards does not change the tax on your purchase
Which Rates Apply at Each Stage
The table shows how a barn is usually classified in England and Northern Ireland, depending on its state at the effective date of your purchase. The effective date is normally completion, or earlier if the contract is substantially performed first.
| State of the barn at completion | Classification | Rates |
|---|---|---|
| Unconverted barn, no planning permission | Non-residential | Non-residential (0%, 2%, 5%) |
| Planning permission or Class Q approval, no work started | Non-residential | Non-residential (0%, 2%, 5%) |
| Conversion work physically under way | Residential (in the process of being adapted) | Residential, and the 5% surcharge can apply |
| Finished barn conversion | Residential | Residential, with the usual reliefs and surcharges |
| Barn in the garden or grounds of a house bought with it | Residential, as part of the house | Residential on the whole price |
| House with barns and land in separate commercial use | Can be mixed | Non-residential on the whole price, if mixed |
Use our non-residential stamp duty calculator for an unconverted barn, and the mixed-use calculator where a house is sold with commercial land or buildings.
The Legal Test
Section 116(1)(a) of the Finance Act 2003 makes residential property of "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". Everything that is not residential property is non-residential.
A barn in agricultural or storage use is not used as a dwelling, and it is not suitable for use as one just because it could be converted. The Upper Tribunal has described work that makes a building usable as a single dwelling for the first time as an "adaptation or alteration", as opposed to a repair (Mudan v HMRC [2024] UKUT 307 (TCC), para 58). So an unconverted barn only becomes residential through the third limb of the test: when it is in the process of being adapted.
A barn is not the same as a derelict house
A run-down house starts as a dwelling and stays one unless it has lost the characteristics of a dwelling. A barn starts as a non-residential building and stays non-residential until conversion is under way. If you are buying a house in poor condition, see our guide to uninhabitable property and stamp duty instead.
Planning Permission and Class Q
Planning permission raises the price of a barn, and stamp duty is charged on that price, but it does not decide the classification. HMRC's manual says: "The process of construction or adaptation must be physically underway for this category to apply. HMRC do not consider obtaining planning permission on its own to be part of this process, if work on the property in line with the planning permission has not yet commenced at the time of the land transaction" (SDLTM00400).
The Upper Tribunal took the same line in Ladson Preston v HMRC [2022] UKUT 301 (TCC), a case about building on bare land: planning permission is "not in itself enough", and there must be "some physical manifestation on the land" (para 44).
Barns that stay non-residential
- A barn with full planning permission for a house, where no conversion work has started
- A barn with Class Q prior approval, where no conversion work has started
- A barn sold with plans, surveys or building regulations approval, but no physical work
Class Q is planning permission too
Class Q of the Town and Country Planning (General Permitted Development) (England) Order 2015 lets an agricultural building change to a dwellinghouse, subject to prior approval. Permitted development is itself planning permission granted by a development order (Town and Country Planning Act 1990, s58(1)(a)), so it sits in the same place as an ordinary planning consent. On its own it does not make the barn residential.
Where conversion has started, the planning permission does matter: HMRC says it "would be a strong indicator of what the building is to be used for" (SDLTM00400). For bare land with planning permission, see our building plot stamp duty guide.
Part-Converted Barns
A barn where conversion work has physically started by completion is a building "in the process of being constructed or adapted" for use as a dwelling, so it is residential property. In Patel v HMRC [2025] UKFTT 373 (TC), the buyer of two former houses part way through conversion into one home, with scaffolding and new concrete floors in place, argued for non-residential rates. The tribunal found the building was "in the process of being constructed or adapted for use a dwelling" (para 62), so it was taxed at residential rates.
What is less settled is the exact point at which a conversion starts. HMRC's rule that a new building counts "at the point where building works on top of the foundations have begun" is written for new construction, and HMRC's manual gives no equivalent test for converting an existing building. In Newsand v HMRC [2024] UKFTT 221 (TC), an office conversion with strip-out work on the day of completion, the tribunal refused to strike the case out because there are "arguable differences" between a process of construction and a process of adaptation (para 34). We have not found a final decision on whether strip-out work alone is enough.
Only work done by completion counts
The interest you buy is assessed "as it stood at the very time of completion" (Ladson Preston, para 62, an MDR case whose approach the Upper Tribunal applied more widely in HMRC v Suterwalla [2024] UKUT 188 (TCC), para 49). Work you start after completion, even on the same day, does not make your purchase residential. Work the seller has already carried out does count, so check the state of the barn before you exchange and keep dated evidence of it.
Surcharge, First-Time Buyer Relief and the 17% Rate
The surcharges and reliefs that apply to homes depend on whether you are buying a dwelling. For the 5% surcharge, a building counts as a dwelling if "it is used or suitable for use as a single dwelling" or "it is in the process of being constructed or adapted for such use" (FA 2003 Sch 4ZA para 18(2)).
| Rule | Unconverted barn | Conversion under way or finished |
|---|---|---|
| 5% additional property surcharge | Does not apply | Applies if you keep another home worth £40,000 or more and are not replacing your main residence |
| First-time buyer relief | Not available | Can qualify, up to £500,000, if you will live there as your only or main residence |
| 17% rate for companies | Does not apply | Can apply above £500,000 unless a relief applies |
The 17% rate applies to a company buying an interest in a single dwelling for more than £500,000 (FA 2003 Sch 4A), and it uses the same "constructed or adapted" test, so it does not reach an unconverted barn. See our guide to the 17% rate for the reliefs that can apply once a barn is a dwelling.
Buying a barn the seller will convert for you
If you buy from a developer under a contract for them to convert the barn, the surcharge rules can treat it as a dwelling even before work starts, where the contract is substantially performed first (Sch 4ZA para 18(5)). Check this with your conveyancer before you sign.
Mixed-use rates top out at 5%. Residential goes to 12%
A flat above a shop, a farm or a house with land can qualify. A specialist checks whether yours does.
Barns Sold With a House or Land
Residential property also includes land that is or forms part of the garden or grounds of a dwelling, "including any building or structure on such land" (FA 2003 s116(1)(b)). A barn in the grounds of a house you are buying is therefore residential along with the house, whatever condition it is in.
In Hyman v HMRC [2022] EWCA Civ 185, the property was a house in a cultivated garden, with "a large barn in a bad state of repair" outside the garden and a meadow (para 8). The whole property was held to be residential, and the Court of Appeal rejected the argument that grounds are limited to what the house reasonably needs.
The answer can be different where barns and land have a separate commercial use. HMRC's manual treats domestic outbuildings, and stables and paddocks suitable for leisure use, as pointing towards grounds, and commercial farming as pointing away from them (SDLTM00465). If part of the purchase is non-residential, the whole price pays non-residential rates.
Mixed: Withers v HMRC [2022] UKFTT 433 (TC)
A barn conversion with an annexe and about 39 acres, where a local farmer grazed around 20 acres under an agreement and about 8.5 acres of woodland were under a Woodland Trust agreement. The tribunal held the grazing and woodland land was not grounds, so the purchase was mixed. HMRC's closure notice had raised the SDLT from £114,500 to £212,500 (para 3), and the appeal was allowed (para 160).
Residential: Harjono v HMRC [2024] UKFTT 228 (TC)
A listed barn conversion with about 3 acres, including a 1.5-acre paddock under a grazing agreement. The tribunal found "the paddock comprised grounds of the property. The property is entirely residential" (para 95).
Whether land is garden or grounds is a question of fact. See our agricultural land stamp duty guide and our roundup of 2026 garden and grounds rulings for more cases.
Worked Examples
England and Northern Ireland rates for purchases completing from 1 April 2025.
Example 1: Barn with Class Q approval, no work started, £250,000
Classification: Non-residential
0% on the first £150,000 = £0
2% on the next £100,000 = £2,000
Total SDLT: £2,000
Returned wrongly as residential by a buyer keeping another home, the bill would be £15,000. That is £13,000 of tax that was never due.
Example 2: Barn with conversion under way at completion, £450,000
Classification: Residential (in the process of being adapted)
0% on the first £125,000 = £0
2% on the next £125,000 = £2,500
5% on the remaining £200,000 = £10,000
Total SDLT: £12,500, or £35,000 if the buyer keeps another home
Bought before any work started, the same barn would be non-residential: £12,000 with no surcharge.
Example 3: Finished barn conversion, £750,000
Classification: Residential
0% on the first £125,000 = £0
2% on the next £125,000 = £2,500
5% on the remaining £500,000 = £25,000
Total SDLT: £27,500, or £65,000 if the buyer keeps another home
The surcharge is where the money is
At standard rates the two schedules differ by no more than £500 between £150,000 and £925,000. The large differences come from the 5% surcharge, first-time buyer relief and the 17% company rate, all of which depend on whether the barn is a dwelling.
Scotland and Wales
Scotland and Wales have their own taxes and rates, but both use the same "in the process of being constructed or adapted" wording in their definitions of residential property (LBTT (Scotland) Act 2013 s59(1)(a); Land Transaction Tax and Anti-avoidance of Devolved Taxes (Wales) Act 2017 s72(1)(a)).
Scotland: LBTT
Revenue Scotland says "Planning permission is not enough to consider a dwelling being under construction", and that where the change is from non-residential to residential, the property "becomes residential as soon as any construction / adaptation for such use begins" (LBTT4010).
Non-residential rates: 0% up to £150,000, 1% to £250,000, 5% above.
Wales: LTT
The Welsh Revenue Authority says obtaining planning permission "would not necessarily change the status of the building, if work on the property in line with the planning permission had not yet commenced at the effective date" (LTTA/1053).
Non-residential rates: 0% up to £225,000, 1% to £250,000, 5% to £1,000,000, 6% above.
Common Mistakes
Paying residential rates because the barn has planning permission
Some online guides still apply residential rates to any barn with planning consent. HMRC's own guidance says the opposite. If you paid residential rates on a barn where no conversion work had started, you may have overpaid. An amendment can be made within 12 months of the filing date, and an overpayment relief claim after that, within 4 years of the effective date. Our stamp duty refund guide explains both routes.
Assuming a finished conversion is non-residential because it was a barn
Once a barn has been converted, it is a house. Its history does not change the rates, and claims for a refund on that basis will fail.
Separating a barn from the house it stands beside
A barn in the grounds of a house is part of a residential purchase. Only a genuinely separate commercial use of the barns and land can make the purchase mixed, and tribunals have found grazing agreements both sufficient (Withers) and insufficient (Harjono) on different facts.
Starting work before completion without thinking about tax
Conversion work on the barn before completion, by you under a licence or by the seller, can turn a non-residential purchase into a residential one. If you already own a home, that can bring in the 5% surcharge on the whole price.
Get advice on borderline barns
Classification is a question of fact at the effective date, and HMRC does not give clearances on questions of fact. For part-converted barns, barns sold with land, or a refund claim on a barn you have already bought, take advice from a stamp duty specialist before you file or amend the return.
Frequently Asked Questions
Do you pay stamp duty on a barn conversion?
Yes, but which rates apply depends on the state of the barn when you complete. An unconverted barn is non-residential property, so in England and Northern Ireland you pay 0% up to £150,000, 2% from £150,001 to £250,000 and 5% above. Once conversion work has physically started, the barn is a building in the process of being adapted for use as a dwelling and residential rates apply. A finished conversion is a house like any other.
Do you pay residential stamp duty on a barn with planning permission?
Not on the strength of the planning permission alone. HMRC says obtaining planning permission on its own is not part of the process of converting a building if work in line with it has not started by the time of the purchase (SDLTM00400). A barn with planning permission and no conversion work under way pays non-residential rates. Revenue Scotland and the Welsh Revenue Authority take a similar view for LBTT and LTT.
Does Class Q approval make a barn residential for stamp duty?
No. Class Q is a permitted development right, and permitted development is itself a grant of planning permission, so the same rule applies: it does not make the barn residential until conversion work has physically begun.
Is there a 5% surcharge on buying a barn to convert?
Not on an unconverted barn. The surcharge only applies to purchases of a dwelling, and a barn becomes a dwelling for this purpose once it is used or suitable for use as one, or is in the process of being constructed or adapted for such use (FA 2003 Sch 4ZA para 18), or where the seller is contracted to convert it for you (para 18(5)). If conversion work has started by completion and you keep another home worth £40,000 or more, the surcharge can apply.
Can I claim first-time buyer relief on a barn?
Not on an unconverted barn. First-time buyer relief is only available on the purchase of a single dwelling that you intend to live in, and a barn where no conversion work has started is not a dwelling. Once conversion is under way, or finished, the barn counts as a dwelling for the relief (FA 2003 Sch 6ZA para 9), so it can qualify within the £500,000 price limit if you will live there as your only or main residence.
Is a barn sold with a house residential or non-residential?
If the barn sits in the garden or grounds of the house, it is residential along with the house. The definition of residential property expressly includes any building or structure on garden or grounds land (FA 2003 s116(1)(b)). In Hyman v HMRC the house, a large barn in a bad state of repair and a meadow were all held to be residential. Barns and land used for a separate commercial purpose, such as a working farm, can make the purchase mixed, so non-residential rates apply to the whole price.
Reviewed by
Julie White
ACAStamp duty specialist since 1999Stamp Duty Land Tax Specialist
ACA and Tax Adviser with a career spanning nearly four decades, specialising in stamp duty planning and advisory work since 1999.