Converting a building into self storage in the UK: the rules, in order

As at 16 October 2026, a warehouse, factory, shop or barn in the UK may become self storage if a permitted development right or the council allows it, and the route depends on its present use, size and nation. A building already in storage use may need no change-of-use application, and a small industrial or farm building may qualify for permitted development. On 16 October 2026 we found no permitted right for a shop or an office in England.

This guide sets out each route, the building rules, fire safety, business rates and the checks to make before you commit. It is general information, not legal advice, and a solicitor has not read it.

Can a warehouse, shop, factory or barn become self storage?

Planning law treats a material change of use as development, which needs permission unless a rule says otherwise. Section 55(1) of the Town and Country Planning Act 1990, which extends to England and Wales, defines development to include “any material change in the use of any buildings or other land”. The planning practice guidance for England says there is no statutory definition of a material change of use and that it is “a matter of fact and degree”.

Use classes group similar uses, and a change within one class is not development. On 16 October 2026 we found no class that names self storage: the words “self storage” and “self-storage” appear in none of the planning sources we searched.

They were the use classes orders and the four nations’ permitted development orders (Parts 3 and 4 for England, Part 3 for Wales and Scotland, Part 4 for Northern Ireland), sections 55, 191 and 192 of the 1990 Act, the planning practice guidance, and the Planning Portal’s use-class and change-of-use pages. The 1987 Use Classes Order covers England and Wales, and Scotland and Northern Ireland have their own.

Class B8 covers “use for storage or as a distribution centre”, and our Class B8 entry reads self storage as falling within it. That is a reading of the wording, not a phrase the order uses.

England’s Class E includes services principally to visiting members of the public, among them “any other services which it is appropriate to provide in a commercial, business or service locality”, and on 16 October 2026 we found no source listed below that says whether a council could place self storage there. Ask the council which class it applies before you rely on any route below.

Which planning route does your building take?

Start with what the building is lawfully used for today. In England, article 3(1A) of the Use Classes Order says that using a building for any other purpose of the same class “is not to be taken to involve development of the land”, and section 55(2)(f) of the 1990 Act says the same for England and Wales. Scotland and Northern Ireland have the same rule for their own classes, in article 3(1) of each order.

The figure follows the permitted development rights we found for each nation, from the building’s present use to the right that applies. It covers only those rights, and every route still assumes the council treats self storage as the class the figure names.

Six points apply to most routes.

• The existing use must be lawful. In England, permitted development does not apply where the existing use, or the building itself, is unlawful (article 3(5) of the 2015 Order), so a buyer relying on Class I needs the B2 use to be lawful. A certificate of lawfulness of existing use (section 191) shows a use is lawful. We did not check the other nations.
• In England a right covers the change of use, not the building work. Class R’s text calls building operations reasonably necessary for the new use “associated operational development”, and the practice guidance says physical works linked to a change of use may need their own planning or building regulations approval.
• Internal works are not development by themselves. Section 55(2)(a), which extends to England and Wales, says works that affect only the interior of a building, or do not materially affect its external appearance, are not development. External works, a change of use, listed status or a planning condition can still need consent.
• The 200 m² rule is for shops. In England the exception for adding over 200 m² of internal floor space applies only to a building used for the retail sale of goods other than hot food (article 44 of the Development Management Procedure Order 2015). Our reading (on 16 October 2026 we found no source below that states it for self storage): an internal mezzanine is outside that exception.
• Wales is not England. Wales shares the 1987 Use Classes Order but keeps the pre-2020 classes, including B1, and its 1995 permitted development order lets an office or light-industrial building go to storage up to 500 m². In England Class I stopped covering B1 on 1 August 2021, and an office is now usually Class E.
• Farm buildings have their own steps. After a Class R change in England the 2015 Order treats the site as having a sui generis use, a use that belongs to no class, and Class R in England and Class 18C in Scotland exclude listed buildings. Our Class R guide covers England in full.

In Scotland, Class 18C needs prior approval of design, transport, access, noise, contamination and flooding, and the change may go ahead if the authority has not given notice within 28 days. It also permits the building operations reasonably necessary for the conversion, including replacing windows, doors, roofs and exterior walls, partial demolition, and access and a hard surface for parking.

In England, a Class R change totalling more than 150 m² on the farm unit needs an application for a determination whether prior approval is needed, covering transport and highways, noise, contamination and flooding. Up to 150 m² the developer tells the council first.

What do the planning applications cost in England?

From 1 April 2026 a planning application for a material change of use of a building or land (fee category 14) costs £610, after fees rose by 3.8% on that date. A certificate of lawfulness costs the full application fee for an existing use and half of it for a proposed use, which for this category is £610 and £305 (our calculation). Which category a council applies is its call.

A proposed-use certificate under section 192 matters beyond its cost: while it is in force, the lawfulness of the use is “conclusively presumed” unless the relevant facts change before the use starts. We did not check fees in Wales, Scotland or Northern Ireland.

What do the building regulations require when you convert?

Planning permission and building regulations are separate approvals. In England and Wales, regulation 5 of the Building Regulations 2010 lists, in paragraphs (a) to (k), the changes that count as a “material change of use”. On 16 October 2026 we found no item in it that names storage, a warehouse or self storage (searched: the whole of regulation 5).

Two items matter here: (f), a building that stops being an exempt Schedule 2 building, such as an agricultural building, and (j), a building that becomes a shop.

On 16 October 2026 we found no source that says whether self storage is a “shop” under the regulations. Their definition of shop includes premises used by the public “for the hiring of any item”, and Approved Document B (ADB) lists “the rental of storage space to the public” under “Shop and commercial” premises.

On 16 October 2026 we found no source that says turning a warehouse into self storage is a material change of use under (j).

If it is, regulation 6 requires the work needed to meet a list of requirements “in all cases”, among them the fire requirements B1, B2, B3, B4(2) and B5, and adds M1 (access to and use of buildings) for a change to a shop under (j). That is a question for building control, so ask before you buy.

Even without a material change of use, the work can be building work. Regulation 3 treats a “material alteration” as work that would make a building fail, or fail more badly, requirements such as structure (Part A), escape (B1) or internal fire spread (B3).

Our reading (on 16 October 2026 we found no source below that states it for self storage): a mezzanine or a row of lockable units can affect those requirements, so building control may look at them.

ADB is guidance, not law. It describes what may be accepted as “one way to comply” with the regulations, and following it “does not guarantee” that work complies. The English Volume 2, for buildings other than dwellings, is the 2019 edition incorporating amendments to 2026, last updated on gov.uk on 16 September 2026.

The duty behind it includes requirement B3(3), which asks for fire-resisting subdivision, automatic suppression or both “to an extent appropriate to the size and intended use of the building”.

In the English volume, ADB’s Table 8.1 limits the floor area of any one storey in a building or compartment. Its Table 0.1 puts “the rental of storage space to the public” in purpose group 4, “Shop and commercial”, and not in the storage group; the Welsh volume does the same in its Table D1. In that group the table has two rows, and the limits are in the figure.

On 16 October 2026 we found no statement in the English Volume 2 of which row premises for hiring out storage space take (searched: Table 0.1 and its notes, Table 8.1 and its notes, the definitions in Appendix A and each mention of a change of use). It decides whether a single-storey conversion is capped at 2,000 m² (about 21,500 sq ft, our calculation) without sprinklers. Ask a fire engineer or building control.

Two other points in the English ADB bear on the layout. Table 2.1 sets the longest escape route in shop-and-commercial premises at 18 m where there is one direction of travel and 45 m where there is more than one.

A mezzanine can change the count of storeys. In the English volume, Appendix A counts a gallery as a storey if it is more than half the area of the space it projects into, while Diagram D5 says that in other purpose groups galleries are not counted.

The Home Office’s fire risk guide for factories and warehouses says a mezzanine covering more than half the floor “may need to be treated as a separate floor”. Building control or a fire engineer reconciles them.

Wales and Scotland have their own versions. Wales publishes its own Approved Document B, Volume 2, a 2006 edition incorporating amendments to 2020, with the latest amendment slip applicable from 20 December 2025, which we did not read. Northern Ireland’s fire guidance is Technical Booklet E, last updated on 6 May 2025; we did not check its rules on a change of use.

In Scotland, section 8 of the Building (Scotland) Act 2003 requires a building warrant for “any conversion of a building”, and a conversion made without one is an offence. The Building (Scotland) Regulations 2004 count a change as a conversion if it lets the public into a building they could not enter before. Our reading: opening a warehouse to self storage customers is likely to fall there.

The Scottish Government publishes an April 2026 non-domestic technical handbook, whose fire section adds guidance on conversions of traditionally constructed buildings.

What does fire safety require once the site is open?

In England and Wales the Regulatory Reform (Fire Safety) Order 2005 is “the main piece of legislation governing fire safety in buildings in England and Wales”, according to gov.uk. The responsible person is the employer for a workplace under their control; otherwise whoever controls the premises in connection with a business; failing that, the owner (article 3).

That person must make a suitable and sufficient fire risk assessment and record it (article 9). They must review it regularly, and particularly when the premises undergo “significant changes, extensions, or conversions” (article 9(3)). They must keep fire safety equipment “in an efficient state, in efficient working order and in good repair” (article 17).

On 16 October 2026 we found no Home Office guide written for self storage. The government’s collection of fire safety guidance for non-domestic premises lists guides for offices and shops, factories and warehouses, open-air events, transport premises, theatres and cinemas, and educational premises.

The nearest is “Fire safety risk assessment: factories and warehouses”, which covers “Factories and warehouse storage premises”. Its page was last updated on 12 September 2023 and its PDF is dated 2006, so check it against current rules. It says to review an assessment after alterations to the building, including the internal layout, and after significant changes in the type, quantity or method of storage of goods.

Scotland and Northern Ireland have their own laws. Under the Fire (Scotland) Act 2005, each employer must assess the workplace for fire risks (section 53(2)(a)), and a person who has control “to any extent” of relevant premises must assess the risks to the people there (section 54).

In Northern Ireland, articles 25 and 26 of the Fire and Rescue Services (Northern Ireland) Order 2006 put duties to assess fire risks on employers and on people in control of premises. We did not read how either nation requires an assessment to be recorded or reviewed.

What changes for business rates?

Tell the Valuation Office (VO) when the nature of your business or your premises changes, so you pay the right amount and do not get a backdated increase. That is gov.uk’s guidance for England and Wales; business rates are handled differently in Scotland and Northern Ireland. The 2026 revaluation took effect on 1 April 2026 using values as at 1 April 2024, and a new duty to tell the VO about property changes “will not become mandatory before 2029”.

The VO’s Rating Manual has a section on self storage, updated on 21 September 2026. It says early units were made from standard warehouses by adding floors and secure areas. Its 2026 valuation scheme starts from the local industrial value and discounts it by 35%, and applies equally to purpose-built stores and “converted warehouses with substantial alterations”.

Upper floors are valued at 85% (first floor), 54% (second) and 39% (third and fourth) of the ground-floor price, and the whole building is one rating unit, not one per storage unit.

The scheme does not suit two kinds of building: traditional purpose-built industrial units, usually multi-storey, with no significant structural alteration that are used for self storage, and a self storage business in a redundant purpose-built office block, which is valued on the scale and matrix for its previous use. Our reading: the building you convert can change how it is valued, so get a rates estimate for that building before you commit.

Our business rates guide and rates calculator cover the rest.

What should you check before you buy or take the building?

Each item below is a separate regime with its own advice. We read one rule for each; none of them is a full guide.

• Energy performance (England and Wales). If you will not own the building, its owner cannot let a property with an energy performance certificate (EPC) below band E unless an exemption applies (2015 regulations). The government’s June 2026 interim response proposes EPC B from 2031 for let buildings over 1,000 m² and drops the 2027 step, which needs secondary legislation. Scotland and Northern Ireland: not checked.
• Asbestos. The duty to manage asbestos in non-domestic premises falls on whoever is obliged to maintain or repair them or, where nobody is, whoever controls them (Control of Asbestos Regulations 2012, regulation 4). The assessment must be reviewed after a significant change in the premises.
• Construction duties. Under the Construction (Design and Management) Regulations 2015 the “client” is any person for whom a project is carried out, and must make suitable arrangements for managing it, including enough time and other resources.
• Listed buildings. Altering a listed building in a way that affects its character needs consent (England: section 7 of the 1990 Act; Scotland: section 6 of the 1997 Act; Northern Ireland: section 85 of the 2011 Planning Act). Wales: section 88 of the Historic Environment (Wales) Act 2023, in force since 4 November 2024, whose fit with the 1990 Act we could not resolve.
• Flood risk (England). The Environment Agency says you should complete a flood risk assessment for all development “including minor development and changes of use” in Flood Zones 2 or 3, and in Flood Zone 1 on a site of 1 hectare or more, among other cases.

Whether the location can support a store at all is a separate test: our site selection guide sets out the data.

In what order does a conversion happen?

On 16 October 2026 we found no source listed below that gives a sequence for self storage, so the order below is ours, drawn from what each rule asks for and when. It assumes you do not yet own the building.

Several steps can run together once you hold the building, and a council or building control may ask for things in a different order. Treat the list as a set of questions to answer, not a programme.

Which UK operators have converted buildings?

Company announcements show conversions at several sizes. Safestore’s results for 2019 say it bought a freehold former retail building in Peterborough in January 2019, converted it into a 42,000 sq ft self storage facility and opened it at the beginning of October 2019.

Its January 2023 results describe a 2.1-acre freehold site in Wigan with an existing warehouse, planned as a store of about 42,700 sq ft “subject to minor planning approvals for elevations and signage”, and its January 2024 results list Wigan among the 2023 openings.

Big Yellow’s 2021 placing announcement says that of the 25 stores in its Armadillo brand, four were new build and the remainder “purpose built conversions of existing buildings”, which makes 21 (our sum). The stores averaged 43,000 sq ft.

What this guide does not cover

• Cost. Our cost to build guide has the sourced figures. This guide gives no price for the building, the work or the fit-out.
• How councils class self storage. We did not search planning appeal decisions, so this guide says nothing on how councils or inspectors treat self storage in practice.
• Wales is changing. The Planning (Wales) Act 2026 consolidates Welsh planning law and is mostly not in force. Its definition of development (section 3) is not in force, so section 55 of the 1990 Act still applies on 16 October 2026, and citations may change.
• Northern Ireland. legislation.gov.uk holds the Use Classes Order (Northern Ireland) 2015 only as made, so later changes, if any, are not shown. We did not check Northern Ireland’s building regulations, asbestos, construction or energy rules.
• What we did not read. Highways and access, contaminated land, the Party Wall etc. Act 1996, hazardous substances consent, the text of the advertisement regulations, Scotland’s energy standards, and fees outside England. The Health and Safety Executive’s pages could not be fetched, so the asbestos and construction rows rest on the regulations alone.

Questions to put to your adviser

• Does the council treat self storage as Class B8, as Class E or as a use of its own, and will it confirm that in a certificate of lawfulness of proposed use?
• Is the building’s present use lawful, and can you show it with a certificate of lawfulness of existing use?
• If the building is a shop or an office in England, what application and what evidence does the council expect?
• Is a self storage conversion a material change of use under regulation 5(j) of the Building Regulations 2010, and which regulation 6 requirements follow?
• Which row of ADB Table 8.1 applies to your building, and do you need sprinklers to exceed 2,000 m² per storey?
• How does building control count a mezzanine under ADB’s Appendix A and Diagram D5?
• In Scotland, does the conversion need a building warrant because it lets the public into the building?
• Which valuation scheme will the VO apply to the converted building, and what rateable value does it give?
• Who holds the responsible-person duty under the Fire Safety Order, and when must the fire risk assessment be in place?
• What energy certificate band does the building have, and does an exemption apply?
• Is the building listed, in a flood zone or subject to an asbestos duty?

Sources

All read on 16 October 2026.

• Use classes: the Town and Country Planning (Use Classes) Order 1987 with article 3; the Scottish Order 1997 and its article 3; the Northern Ireland Order 2015 as made and its article 3.
• Permitted development: the England 2015 Order, Part 3, Part 4 and article 3; the Wales 1995 Order, Part 3; the Scotland 1992 Order, Part 3, Class 18C and Class 22B, with the Scottish Government’s Circular 2/2024; the Northern Ireland 2015 Order, Part 4.
• The Town and Country Planning Act 1990: section 55, section 191 and section 192; article 44 of the Development Management Procedure Order 2015.
• Guidance: the planning practice guidance on when permission is required and lawful development certificates; the Planning Portal’s use classes and change of use pages.
• Fees: the government’s planning fees from 1 April 2026 and its fee table.
• The Planning (Wales) Act 2026: section 3 and section 409.
• Building regulations: the Building Regulations 2010, regulations 2, 3, 5 and 6, with Schedule 1 and Schedule 2.
• Approved Document B: the gov.uk page and Volume 2 (England); the Welsh Government’s page and Volume 2.
• Scotland and Northern Ireland: the Building (Scotland) Act 2003, section 8; the Building (Scotland) Regulations 2004, Schedule 2; the Scottish Government’s building standards page; Northern Ireland’s Technical Booklet E.
• Fire safety: the Fire Safety Order 2005, articles 3, 9 and 17; the government’s collection of fire safety guidance and its guide for factories and warehouses with the PDF; the Fire (Scotland) Act 2005, section 53 and section 54; the Fire and Rescue Services (Northern Ireland) Order 2006, article 25 and article 26.
• Business rates: gov.uk on changes to premises, the 2026 revaluation and the duty to notify; the VO’s Rating Manual on self storage.
• Energy performance: regulation 22 and regulation 27 of the 2015 regulations, gov.uk’s guidance and interim response.
• Other duties: the Control of Asbestos Regulations 2012, regulation 4; the Construction (Design and Management) Regulations 2015, regulation 4; the Environment Agency’s flood risk assessment guidance.
• Listed buildings: the Planning (Listed Buildings and Conservation Areas) Act 1990, section 7; the Historic Environment (Wales) Act 2023, section 88; the 1997 Act for Scotland, section 6; the Planning Act (Northern Ireland) 2011, section 85.
• Operators: Safestore’s final results of 7 January 2020, 17 January 2023 and 17 January 2024; Big Yellow’s placing announcement of 23 June 2021.