Selling a House with Outbuildings

Outbuildings are one of the most common features that generate additional enquiries during a property sale. Whether you have a timber garden shed, a brick-built workshop, a stable block, or a converted annexe, the buyer's solicitor will want to understand what the structure is, whether it has the necessary permissions, and how it fits within the legal boundaries of your property.

Most of these enquiries are straightforward to answer if you have prepared properly. This guide explains what outbuildings are in legal terms, what buyers and their solicitors check, and how to get your documentation in order before you list your property for sale.

What counts as an outbuilding?

In planning and property law, an outbuilding is any structure within the curtilage of a dwelling house that is not part of the main house itself. The term covers a wide range of structures:

• Garden sheds and storage buildings
• Garages (detached from the main house)
• Workshops and studios
• Greenhouses and potting sheds
• Summerhouses and garden rooms
• Stables and field shelters
• Barns and agricultural buildings
• Home offices and garden offices
• Self-contained annexes and granny flats

The legal treatment of each type varies significantly depending on the size, construction, use, and location of the building. A small prefabricated shed at the bottom of a suburban garden raises entirely different questions from a converted stone barn used as a home office or a stable block on a rural property with land attached to the house.

Planning permission for outbuildings

The first question a buyer's solicitor will ask about any outbuilding is whether it has the necessary planning permission. Many outbuildings benefit from permitted development rights under the Town and Country Planning (General Permitted Development) (England) Order 2015, which means they do not require a formal planning application. However, permitted development is subject to strict conditions.

Permitted development conditions for outbuildings

An outbuilding qualifies as permitted development only if it meets all of the following requirements:

• The outbuilding is used for purposes incidental to the enjoyment of the dwelling house — not as a separate dwelling or for commercial activity
• It does not cover more than 50% of the total curtilage area (excluding the footprint of the original house)
• It is not forward of the principal elevation of the house
• The maximum eaves height is 2.5 metres if within two metres of a boundary
• The maximum overall height is 4 metres for a dual-pitched roof or 3 metres for any other roof type
• On designated land (conservation areas, AONBs, National Parks, the Broads, or World Heritage Sites), the outbuilding is not positioned to the side of the house and does not exceed 10 square metres in floor area

If any of these conditions are not met, full planning permission is required. Properties that are listed buildings have no permitted development rights for outbuildings within their curtilage, and listed building consent is needed in addition to planning permission.

When planning permission is missing

If an outbuilding was erected without planning permission and does not qualify as permitted development, the situation is not necessarily fatal to the sale. There are several possible routes:

1. Certificate of lawfulness. If the outbuilding has been in place for more than four years without enforcement action, you can apply to the local planning authority for a certificate of lawful development (CLUD). This confirms that the building is immune from enforcement and gives buyers and lenders confidence that it can remain.
2. Retrospective planning application. You can apply for planning permission after the fact. The local planning authority will assess the application on its merits as if the building had not yet been constructed.
3. Indemnity insurance. Where obtaining a certificate of lawfulness or retrospective permission is not practical, your solicitor may arrange an indemnity policy to cover the buyer against the risk of enforcement action. Many lenders accept this approach, particularly for minor structures.

Building regulations and outbuildings

Building regulations are separate from planning permission and deal with the structural integrity, safety, and energy efficiency of buildings. Whether an outbuilding requires building regulations approval depends on its size, construction, and use.

When building regulations apply

Building regulations approval is generally required if the outbuilding:

• Has a floor area exceeding 15 square metres (or 30 square metres if it is more than one metre from any boundary and is not a sleeping accommodation)
• Contains sleeping accommodation (for example, an annexe or guest room)
• Has electrical installations, plumbing, or drainage work that falls under Part P or Part H of the Building Regulations
• Has been converted to habitable use, such as a home office with heating, insulation, and fixed electrical supply

Simple garden sheds, greenhouses, and carports under 15 square metres that do not contain sleeping accommodation and are not substantially glazed are generally exempt. However, the buyer's solicitor will still want confirmation of the position, and this should be addressed on the TA6 form.

Missing building regulations sign-off

Where building regulations approval was required but not obtained, the options mirror those for missing planning permission: you can seek a regularisation certificate from the local authority (which involves an inspection and a fee, typically £400 to £800), or your solicitor can arrange indemnity insurance. Most buyers and lenders prefer indemnity insurance for older outbuildings because regularisation can involve opening up parts of the structure for inspection. For more on this topic, see our guide on missing building regulations sign-off.

Types of outbuilding and their impact on the sale

If you are selling a detached house, outbuildings are often a key feature that buyers are looking for. Making sure the paperwork is in order turns a potential obstacle into a genuine selling point.

Outbuildings and the TA6 form

The TA6 Property Information Form is where you disclose details about your property to the buyer. Several sections are directly relevant to outbuildings:

• Section 1 — Boundaries. The plan attached to the TA6 should show the position of all outbuildings within the property boundary. If an outbuilding is close to or on a boundary, note this clearly.
• Section 4 — Planning and building control. Disclose any outbuildings that were the subject of a planning application or building regulations application, whether approval was granted, and whether a completion certificate was issued. If you relied on permitted development, state this clearly.
• Section 7 — Environmental matters. If any outbuilding contains or contained hazardous materials such as asbestos cement sheeting (common in pre-1990s garages and sheds), disclose this. Also disclose any fuel storage such as heating oil tanks in outbuildings.
• Section 9 — Services. If an outbuilding has its own electrical supply, water supply, or drainage, these services need to be disclosed and the buyer will want to know whether they were installed by a qualified professional and certificated.

Thorough disclosure on the TA6 reduces the number of additional enquiries the buyer's solicitor raises and keeps the transaction moving. Incomplete or evasive answers about outbuildings are a red flag that can lead to protracted negotiations.

Boundary and access issues with outbuildings

Outbuildings positioned near or on property boundaries are a frequent source of enquiries and occasionally disputes. The buyer's solicitor will compare the title plan held at HM Land Registry with the physical position of the outbuilding to check for:

• Encroachments. An outbuilding that extends beyond your title boundary onto neighbouring land is an encroachment. This must be resolved — either by negotiating with the neighbour for a transfer of the strip of land, obtaining their written consent, or arranging indemnity insurance.
• Access rights. If an outbuilding such as a stable or workshop is accessed via a route that crosses neighbouring land, there must be a legally registered easement or right of way. Informal access arrangements are not binding on future owners of the neighbouring land.
• Party wall considerations. An outbuilding wall built on or astride a boundary may be a party wall under the Party Wall etc. Act 1996. If you built or altered such a wall without serving the required notice, your solicitor may recommend indemnity insurance.

If your property includes land beyond the immediate garden — paddocks, orchards, or woodland — outbuildings on that land create additional questions about access, drainage, and maintenance. Our guide on selling a house with land covers these scenarios in detail.

Insurance and outbuildings

The buyer's mortgage lender will require confirmation that all structures on the property are covered by buildings insurance for their full rebuild cost. This includes outbuildings.

Standard home insurance policies typically provide a basic level of cover for outbuildings, but there are common gaps:

• Cover limits. Many policies cap outbuilding cover at £5,000 to £15,000. A brick-built workshop, stable block, or garden annexe may exceed this.
• Named structures. High-value outbuildings may need to be specifically listed on the policy with an individual rebuild cost.
• Contents cover. Tools, machinery, or equipment stored in workshops or stables may not be covered under a standard contents policy and may need a separate rider.
• Non-standard construction. Outbuildings with timber frames, flat roofs, or non-standard materials may attract higher premiums or exclusions.

Review your buildings insurance policy schedule before listing your property. If your outbuildings are underinsured or not listed, update the policy. This avoids a last-minute problem when the buyer's lender requests confirmation of adequate cover.

Outbuildings and property valuation

The buyer's mortgage lender will instruct a RICS surveyor to value the property. How outbuildings affect the valuation depends on several factors:

• Quality and condition. A well-maintained, purpose-built outbuilding in good structural condition adds value. A dilapidated structure with a collapsing roof or significant damp may be valued as a liability.
• Compliance. Outbuildings with the correct planning and building regulations paperwork are valued more favourably than those without. Non-compliant structures carry enforcement risk.
• Functionality. A home office, workshop, or annexe that serves a clear and desirable purpose attracts a premium. Since the pandemic, garden offices and self-contained work spaces have become particularly sought-after features.
• Proportionality. An outbuilding that is disproportionately large or elaborate relative to the main house may not add proportionate value. Surveyors look at the overall balance of the property.

Rural properties with stables, barns, or workshops are typically valued on a per-acre basis for the land and individually for the structures. For rural sales involving outbuildings and land, see our guide on selling a cottage in the UK, which covers many of the same valuation considerations.

Preparing outbuilding documentation before listing

The most effective way to prevent outbuilding-related delays is to assemble your documentation before you put the property on the market. Here is a practical checklist:

1. List every outbuilding. Walk the property and note every structure that is not part of the main house, including sheds, garages, greenhouses, and any converted spaces.
2. Gather planning documentation. For each outbuilding, locate the planning permission, permitted development confirmation, or certificate of lawfulness. If none exists, discuss with your solicitor whether one is needed.
3. Gather building regulations documentation. Locate any completion certificates, regularisation certificates, or electrical installation certificates (Part P) for outbuildings that required building regulations approval.
4. Check the title plan. Obtain official copies of your title from HM Land Registry (£7 per document) and confirm that the title plan accurately reflects the position and extent of all outbuildings. Note any structures near boundaries.
5. Review your insurance policy. Confirm that all outbuildings are covered for their full rebuild cost. Update the policy if needed.
6. Complete the TA6 early. Fill in the relevant sections of the TA6 form with full details of every outbuilding, including what consent was obtained and what services are connected.
7. Photograph the outbuildings. Dated photographs of each outbuilding showing its current condition can be useful evidence if questions arise during the sale about when a structure was built or what condition it was in at the point of sale.

Taking these steps before you list saves weeks of back-and-forth enquiries during conveyancing and demonstrates to buyers that you are a well-prepared seller. For a full breakdown of the costs involved in the conveyancing process, see our conveyancing costs breakdown.

Special considerations for rural properties

Rural properties often have multiple outbuildings — barns, stables, workshops, field shelters, and stores — that create additional complexity:

• Agricultural ties. Some outbuildings on agricultural land have restrictions on their use linked to agricultural occupancy conditions or planning conditions that limit the building to agricultural purposes only.
• Class Q conversion rights. Agricultural buildings may benefit from Class Q permitted development rights, which allow conversion to residential use without full planning permission. Buyers may be interested in this potential, and you should be aware of whether your outbuildings qualify.
• Drainage and septic tanks. Rural outbuildings may have separate drainage arrangements, including connections to private septic tanks or treatment plants. These are regulated by the Environment Agency, and the buyer's solicitor will want to see the relevant permits.
• Listed buildings and heritage. In rural areas, outbuildings such as barns, cart sheds, and oast houses may be listed in their own right or fall within the curtilage of a listed building. Any alterations without listed building consent are a criminal offence, and buyers will require evidence of compliance.

Asbestos in outbuildings

Asbestos cement sheeting was widely used in the construction of garages, sheds, and agricultural buildings throughout the UK until its ban in 1999. If your outbuildings predate 2000, there is a reasonable chance they contain asbestos-containing materials, particularly in:

• Corrugated roof sheets
• Flat roof panels
• Wall cladding
• Soffits and fascia boards
• Rainwater goods (guttering and downpipes)

Asbestos that is in good condition, undisturbed, and not deteriorating can generally be left in place and managed. However, you must disclose its presence on the TA6 form, and the buyer's surveyor will note it in their report. If asbestos is damaged, crumbling, or likely to be disturbed by the buyer's planned works, a licensed asbestos removal contractor should be engaged. Removal costs vary but typically range from £500 to £3,000 for a standard garage or shed roof.

Sources

• Planning Portal – Outbuildings: permitted development rights (planningportal.co.uk)
• Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2, Part 1, Class E – legislation.gov.uk
• Ministry of Housing, Communities and Local Government – Permitted development rights for householders: technical guidance (gov.uk)
• HM Land Registry – Practice Guide 40: Land Registry plans (gov.uk)
• Building Regulations 2010, Part P (Electrical safety) – legislation.gov.uk
• Health and Safety Executive – Asbestos in the home (hse.gov.uk)
• RICS – RICS Home Survey Standard, 1st edition (rics.org)
• Law Society of England and Wales – Property Information Form (TA6), 4th edition, 2020
• Party Wall etc. Act 1996 – legislation.gov.uk

Frequently asked questions