Material change of use: key risks and tips for getting it right

Introduction

If you carry out development (as defined in s.55 Town and Country Planning Act 1990), you will usually need planning permission, without which it may be unlawful and subject to enforcement action. There are two limbs of “development”:

1. operational works (building and engineering works) 
2.  material change of use

This article explores the second limb—material changes of use. Particularly, we examine some common issues which arise when considering whether the use (existing and/or proposed) of a property is lawful where there is no planning permission for that use, and permitted development rights for proposed material changes of use which can be exercised under the GPDO (General Permitted Development Order).

In the absence of a planning permission that authorises the current use of a property, its use can become lawful by long use. Long use immunity from enforcement occurs under s.171B of the Town and Country Planning Act 1990 after which ‘no enforcement action may be taken’. In practice this means that once the immunity is achieved, the use which has continued throughout this time is now the lawful use. The time limit for long use immunity is 10 years from the date of the use (unless the use began before 25 April 2024 for use as a dwelling house in which case it will be four years.)

Use must be continuous and uninterrupted, but one should note that there is complex case law on determining continuity. Examples such as holiday chalets do not require year round use for continuity to be established. Once the new lawful use has crystallised, continuity does not need to continue for the same use to remain lawful at a later date, provided that use is not subsequently abandoned or subject to a further material change of use. 

Evidencing a material change

In terms of evidencing that a material change of use has accrued over 10 years, the following may be helpful:

• occupation agreements (e.g. leases) – permitted user clauses
• agents’ brochures (historic and current)
• Schedules of Dilapidations (can contain details of uses and floorplans)
• Licences to Alter (can contain details of works carried out to facilitate a use)
• business rates records (can have breakdown of uses of floorspaces)
• sales/distribution contracts can all be useful evidence to determine lawful use

Where there is 10 years of continuous lawful use, sometimes it can be helpful to make a Certificate of Lawful Existing Use or Development (CLEUD) whereby if granted the local planning authority (LPA) confirms the use as lawful. This can be an appropriate strategy if future planning applications need to be made and it is therefore important to establish what the baseline lawful use comprises and/or it can assure future buyers. An alternative is to obtain indemnity insurance against the risk of enforcement action; premiums for the same usually being low if there is robust clear evidence of 10 years use. 

Where applicants apply for a CLEUD, the evidence should be precise and unambiguous and the determination is made on the balance of probability meaning that the LPA should usually grant these if they do not have any evidence to contravene an application. Our planning team regularly act on such CLEUD applications.

Changes of use pursuant to the GPDO are increasingly common. This route requires careful consideration and should be undertaken as to the relevant permitted development rights. In particular check the planning history to ascertain:

1. any relevant planning permission which has authorised the current building that could have removed these rights; precise wording of any such condition is important
2. whether the current use is lawful (if not lawful then the relevant permitted development right to change from the same may not be available)

 For conversion schemes that fall within the Environmental Impact Assessment Regulations (generally more than 150 residential units), an EIA screening process must also be undertaken ahead of reliance on any permitted development right or prior approval.

For some permitted development rights in the GPDO, a prior approval application to the LPA is required before reliance can be made on the relevant permitted development right. In common with CLEUD applications, prior approval applications are not determined by reference to policies in the development plan; only the criteria set out in the GPDO are considered albeit some of those criteria allow reference to specific development plan policies.

Overview of Class MA

One of the most common permitted development rights for property developers which requires a prior approval application is Class MA of the GPDO – commercial, business and service uses to dwelling houses. These applications have recently hit a record high due to relaxation of restrictions and availability of office space following increasing remote working.

Class MA can be an effective and efficient way of repurposing disused office space; providing residential accommodation without the emissions or costs involved in new-build development. However, there are things to consider for developers, and not all office blocks will lend themselves to the amenities required for residential accommodation. LPAs will need to consider the impact from remaining commercial premises when deciding applications in areas important for certain commercial uses, availability of natural light and minimum space standards. 

Practical and legal considerations for developers

A particular requirement of Class MA (and several other permitted development rights) is the need to complete the development within three years. Depending on the quantum of conversion works, this can be challenging. If the conversion works are not completed within that time frame there is a risk of enforcement action. This can impact future sales/occupation of those residential units. Whilst s.73 applications can be made to extend the time for completion of the development, there must be strong reasons for this delay which lie outside of the control of the developer.

Conversions for high rise buildings via the prior approval route can be challenging, as the same require Building Control Approval from the Building Safety Regulator before construction can commence. Delays in this process can significantly eat into the programme for conversion works.  It is also important to note that planning permission can be separately required for facilitating operational works depending on the particular permitted development right. This should be obtained before any works commence.
Developers will need to consider s106/CIL obligations which can arise to mitigate the impacts of the development. CIL obligations are a particular area of concern where office buildings have fallen out of use over time, as the ability to offset in use floorspace from the CIL charges attaching to an office to residential conversion will be unavailable if the offices have not been in lawful use for a continuous period of at least 6 months within the last 3 years.

Establishing the lawfulness of a material change of use—whether through long use immunity or permitted development rights—requires careful planning, robust evidence and a strategic approach. CLEUD applications can provide certainty and de-risk future planning activity or transactions, while permitted development rights offer a potentially streamlined route for change of use, provided all conditions and limitations are met. Developers should be aware of the procedural and evidential pitfalls, especially where prior approval, Building Safety Regulator input, or CIL liabilities may apply. Early due diligence and legal advice are key to navigating these complexities effectively.