Planning permission is not Building Regulations approval.

A change of use is often discussed as though one consent unlocks the whole project. In England, that is not how the system works. Planning control and Building Regulations address different questions, and other consents may sit alongside both.

For a commercial building being considered for residential or mixed use, the distinction is not an administrative footnote. It affects whether the proposed layout can be delivered, the scope and cost of the work, the timing of professional appointments, lender confidence and the price that can sensibly be paid.

What the planning route establishes

Planning control is concerned with the use and development of land and buildings. A material change of use can require planning permission. In some cases, national permitted development rights provide a planning route without a conventional full planning application, but those rights remain subject to their own limitations and conditions.

Where prior approval is required, the local planning authority considers only the matters specified by the relevant permitted development right. Prior approval is not a general exemption from planning control, and it cannot safely be assumed from the building type alone.

Four planning checks matter at acquisition stage

1. Existing lawful use: establish what the property is lawfully used for, rather than relying only on the sales description or current occupation.
2. Correct consent route: decide whether the proposal needs full planning permission, falls within a permitted development right, requires prior approval, or needs another planning application.
3. Local restrictions: check planning conditions, obligations and any Article 4 direction. An Article 4 direction can withdraw specified permitted development rights in a defined area.
4. Associated physical works: a change of use route does not automatically authorise every external or operational alteration. Windows, shopfronts, extensions, plant, refuse arrangements and other works may need separate consideration.

National planning guidance is explicit that physical works associated with a change of use may require separate planning permission or Building Regulations approval. It also warns that other consents can be required, including listed building consent where relevant.

Planning control and Building Regulations compared

What Building Regulations establish

The Building Regulations 2010 cover building work in England and Wales, with the approval process described here applying to England. The regulations define several circumstances that amount to a material change of use. One example is where a building is used as a dwelling when it was not used as one before.

That matters because a project can trigger technical requirements through the change of use itself, even where the planning route is comparatively straightforward. The final requirements depend on the building, the proposed work and the way the regulations apply to that particular material change.

The government publishes Approved Documents as guidance on ways to meet the Building Regulations. They give expected performance and practical examples for common situations. They are not a replacement for project-specific design, professional judgement or building control review.

Technical subjects that can shape a conversion

• Structure: the capacity of existing floors, roofs and walls, plus the effect of new openings, stairs and concentrated loads.
• Fire safety: escape, compartmentation, fire resistance, detection, alarm arrangements and the interaction between different uses.
• Resistance to sound: separation between dwellings and between residential and commercial accommodation.
• Ventilation: whole-dwelling and extract ventilation, air paths and the practical route for ductwork.
• Sanitation and drainage: water supply, hot water safety, foul drainage, gradients and realistic connection routes.
• Energy performance: the building fabric and fixed services, including how upgrades interact with moisture and existing construction.
• Access and use: applicable access requirements, circulation, entrances and internal arrangements.

Not every Approved Document applies in the same way to every project. The point is more disciplined: an appraisal should identify the relevant technical questions early enough for them to influence the layout, works budget and acquisition decision.

Where commercial risk appears

The planning layout may look efficient on paper while the technical layout consumes the space that appeared to create value. An escape route can reduce lettable or saleable area. Acoustic construction can change wall build-ups. Drainage routes can dictate where kitchens and bathrooms actually fit. Structure can make a proposed opening disproportionate. Ventilation and service distribution can reduce ceiling height or require external alterations.

These are not arguments against conversion. They are reasons to avoid valuing the completed scheme before the building has been tested against the work needed to deliver it.

A planning decision also does not settle every separate regime. Depending on the asset and proposal, the review may need to include listed building consent, advertisement consent, licensing, highways agreements, party wall matters, easements, restrictive covenants, freeholder consent and lender requirements. These do not all arise on every scheme, but they should be screened rather than assumed away.

A practical parallel review before commitment

A commercially disciplined conversion appraisal should let planning and technical work inform one another. A useful early sequence is:

1. Confirm the property baseline. Obtain title information, planning history, measured information, occupancy details and the best available record of existing construction and services.
2. Define the intended use precisely. Avoid broad labels such as “residential conversion” where the operational model, number of units and retained commercial use materially affect the assessment.
3. Identify the planning route. Test full permission, permitted development and prior approval honestly against national requirements, local restrictions and the actual works proposed.
4. Test a technical layout. Ask the architect, fire adviser, structural engineer, building services designer and building control professional for proportionate input where the risks justify it.
5. Map the services. Establish realistic routes and capacity for drainage, water, electricity, heating, ventilation, data, refuse and any retained commercial operation.
6. Price the compliance-driven work. Include the elements created by the technical strategy, not only the visible refurbishment.
7. Reconcile area, cost and value. Update the appraisal using the deliverable layout and evidenced works scope rather than the first concept.
8. Set conditions and contingencies. Where uncertainty remains, reflect it in the offer, contract structure, programme, finance and contingency rather than treating it as solved.

This does not mean commissioning every consultant report before making any offer. The proportionate response depends on the asset, information available and risk being taken. It does mean directing early professional effort towards the issues most capable of changing the deal.

The disciplined conclusion

Planning permission answers a planning question. Building Regulations approval addresses applicable technical requirements. Neither should be used as shorthand for the other, and neither should be assumed to resolve every additional consent.

For conversion-led property, the strongest appraisal is one where use, layout, compliance, construction and operation are considered together. That is how a promising idea becomes a scheme that can be designed, funded, built and used with fewer late surprises.

Primary and authoritative sources

1. GOV.UK: Building regulations approval, when you need approval
2. GOV.UK Planning Practice Guidance: When is permission required?
3. GOV.UK: Approved Documents collection
4. The Building Regulations 2010, regulation 5: Meaning of material change of use
5. Planning Portal: Permitted development rights, prior approval and Article 4 directions

Important: This article is general information about the English planning and building control systems. It is not legal, planning, building control, fire-safety, structural, valuation or financial advice. Requirements depend on the property and proposal. Use suitably qualified UK professionals and confirm the current position with the relevant authority before relying on a route or starting work.