Offices to laboratories within Class E
Moving from offices to laboratory space is usually a movement within Class E and needs no planning permission. The external plant, the servicing and the containment level are the real questions.
Converting office floorspace to laboratory space is normally a movement within Class E, which means no planning permission is needed for the change of use itself. Class E(g)(i) covers offices and Class E(g)(ii) covers research and development of products or processes, both within the same class, and a change of use within a class is not development under section 55 of the Town and Country Planning Act 1990. The office to laboratory planning question that actually needs answering is what the fit-out does to the outside of the building.
That is where the applications come from. Air handling units on the roof, a fume cupboard discharge stack above the parapet, condensers in a courtyard, a new goods door, a gas cylinder compound at the service yard.
Why most laboratory uses sit within Class E
The 2020 amendments to the Use Classes Order folded the old A1, A2, A3, B1 and D1 uses into a single commercial, business and service class. Within it, Class E(g) has three limbs: offices, research and development of products or processes, and any industrial process.
All three are qualified by the same wording. The use must be one that can be carried out in a residential area without detriment to the amenity of that area by reason of noise, vibration, smell, fumes, smoke, soot, ash, dust or grit.
Most laboratory work passes that test comfortably. Analytical chemistry, molecular biology, tissue culture, computational work with a small wet lab attached, medical device development and formulation at bench scale all sit inside the class. The building is still an office building in planning terms, and the planning unit is unchanged.
Where the use falls outside the class
Two situations take a laboratory out of Class E. The first is scale. A pilot plant producing material at volume, with tanker deliveries and process emissions, is manufacturing rather than research, and Class B2 is the likely home.
The second is the amenity qualification. Continuous extract fans running at night, solvent odour at the stack, a standby generator tested weekly, or a delivery pattern involving articulated vehicles will each be tested against that wording. Fail it, and the use falls outside E(g) even if the activity is described as research.
Sui generis sits behind both. Where a use does not fit any class, it is a use in its own right, and every material change to or from it needs permission. Getting the description of development right matters here, because a description that reads "laboratory and ancillary offices" invites a different answer from one that reads "research and development within Class E(g)(ii)".
Plant, extraction and external alterations
Operational development is assessed separately from use. The fit-out items that normally need planning permission are:
- Roof-mounted air handling units, chillers and condensers, particularly where they sit above the existing parapet line.
- Fume cupboard discharge stacks, which need height for dispersion and are therefore visible.
- Acoustic enclosures and louvred screens, which are often taller than the plant they hide.
- New external doors, loading bays and level access for equipment.
- Gas cylinder and cryogenic storage compounds in the service yard.
- Plant at ground level in courtyards, where noise reaches upper floor windows of neighbouring buildings.
On a listed building or in a conservation area, each of these also engages heritage duties, and roof plant on a historic building is one of the harder cases to make.
The evidence councils ask for is predictable. A Noise Impact Assessment to BS 4142:2014+A1:2019, comparing the rating level of the plant with the background sound level at the nearest sensitive receptor, and a Ventilation and Extraction Statement covering the discharge point, the efflux velocity and the filtration.
| Element | Use class effect | Consent usually needed |
|---|---|---|
| Bench laboratories in former office floors | Within Class E | None for the use |
| Roof air handling plant | None | Planning permission |
| Fume cupboard stack above parapet | None | Planning permission |
| Bulk solvent storage | May take use outside E | Planning permission and permitting advice |
| Pilot-scale production | Likely Class B2 | Change of use application |
Hazardous substances and permitting overlaps
Planning is not the only regime. Storing hazardous substances above the controlled quantities requires hazardous substances consent under the Planning (Hazardous Substances) Act 1990, applied for to the hazardous substances authority, which is usually the same council.
Work with biological agents is regulated by the Health and Safety Executive, and containment level determines the engineering rather than the planning position. Radioactive materials bring in environmental permitting. Clinical and chemical waste streams bring in duty of care obligations and a collection contract.
None of these replaces planning permission and none of them is replaced by it. The practical risk is a project team that assumes a planning consultant is covering the permitting question while the permitting adviser assumes planning has it.
Servicing, waste and deliveries
Laboratories generate a different servicing pattern from offices. Daily consumables, weekly gas cylinder exchanges, clinical waste collections, liquid nitrogen deliveries and occasional equipment moves involving a lorry-mounted crane.
Where the building has an existing service yard with capacity, this rarely causes a problem. Where the offices were serviced from a shared basement car park with a 2.1 metre height restriction, it does.
Councils cannot require a transport assessment for a use that does not need permission. They will look closely at servicing when the plant application comes in, and a swept path drawing showing how a rigid vehicle reaches the yard is worth including.
An illustrative scheme
This example is illustrative. A 1990s four-storey office building on an edge-of-centre business park is let to a company taking two floors for analytical laboratories. The use sits within Class E(g)(ii), so no change of use application is made. The fit-out needs six fume cupboards, a roof-mounted air handling unit and a discharge stack 2.5 metres above the parapet.
The applicant submits a full application for the plant with an acoustic assessment, a dispersion note on the stack, elevations showing the louvred screen in a dark grey finish, and a short planning statement. Conditions attached to the permission set a plant noise limit and restrict the hours of any testing of the standby generator. Total programme from submission to decision, about ten weeks.
What still needs an application
Work through the scheme in this order. Confirm the use falls within Class E and record the reasoning. Consider a certificate of lawful proposed use if a funder or tenant needs certainty. Then list every external change and every piece of plant, and treat that list as the application.
A focused Planning Statement that sets out the use class analysis first and the plant second gives the case officer the structure they need, because the two questions are answered under different parts of the Act. Browse all 66 report types to see which technical documents the plant application is likely to need.
This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.
PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
Frequently asked questions
Does converting offices to laboratories need planning permission?
Usually not for the use itself. Offices fall within Class E(g)(i) and research and development within Class E(g)(ii), and movement between uses in the same class is not development under section 55. Permission is normally still needed for the external plant, flues and structural alterations the fit-out requires, and for any change to the building's appearance.
What takes a laboratory outside Class E?
The E(g) sub-classes only apply where the use can be carried out in a residential area without detriment to amenity by reason of noise, vibration, smell, fumes, smoke, soot, ash, dust or grit. A process generating notable fume discharge, continuous plant noise or heavy vehicle movements fails that qualification and falls into Class B2 general industrial or becomes sui generis.
Do I need a lawful development certificate?
It is often worth having. A certificate under section 192 confirming that the proposed laboratory use is lawful gives the funder and the incoming tenant certainty, and it heads off an enforcement enquiry from a neighbour once the plant appears on the roof. The council decides the application on the law and the evidence rather than on planning merits.
What about containment level 3 facilities?
Containment level is a health and safety classification rather than a planning one, and the Health and Safety Executive regulates work with biological agents. A containment level 3 facility can still sit within Class E if the amenity qualification is met, but the ventilation, filtration and effluent arrangements are more demanding, and the discharge stack is usually the element that needs planning permission.
Will the council want a noise assessment?
If external plant is proposed, almost certainly. Environmental health officers normally ask for an assessment carried out to BS 4142 comparing the rating level of the plant with the background sound level at the nearest noise-sensitive receptor, with a proposed condition setting a limit. Getting the acoustician involved before the plant is selected avoids redesigning the enclosure later.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.