Industrial capacity in London: measuring no net loss

No net loss of industrial capacity is a capacity test, not a floorspace test, and that distinction decides whether a London redevelopment scheme is acceptable. A proposal can replace 6,000 square metres of single-storey warehousing with 7,500 square metres of stacked industrial units and still lose capacity, because the yard has gone, the clear internal height has dropped from 9 metres to 5.5 metres, and an articulated lorry can no longer reverse onto a dock. Floorspace went up. Capacity went down.

The policy framework is set out in industrial land in London: no net loss and SIL policy. What follows is how to measure and evidence the capacity itself.

What capacity actually consists of

Industrial capacity has five components, and a scheme has to account for all five rather than only the first.

Floorspace, measured as gross internal area, by use class. Clear internal height to the underside of the lowest structural member or service, which determines racking and plant. Yard and service area, measured in square metres and in usable depth. Vehicle access, expressed as the largest vehicle that can enter, manoeuvre and leave, with tracking to prove it. And operational freedom, meaning hours of operation, noise headroom, loading at night, and whether the use can expand without consent.

A replacement scheme that reports only the first of those has not addressed the policy. A borough officer reading it will ask about the other four in the first round of comments, and the answer will often require a redesign rather than an addendum.

Floor loading belongs in the same list on multi-storey schemes. An upper floor designed to 15 kilonewtons per square metre serves light industrial and storage. One designed to office loadings does not serve either, whatever the floorspace schedule says.

Measuring floorspace against capacity

Set out the comparison as a table, existing against proposed, with every component in it.

Take the existing position from a measured survey and the planning history rather than from an agent's particulars. Vacancy is not evidence of low capacity, and a unit standing empty because the lease ended still has whatever capacity its fabric gives it.

The units matter in the net column. Expressing a yard loss as a percentage hides it. Expressing it as a reduction from 32 metres to 18 metres of usable depth makes the operational consequence legible, because 18 metres will not take an articulated vehicle plus a loading apron.

Intensification and co-location, in practice

The policy answer to development pressure on industrial land is intensification, co-location or substitution. Each carries a different evidence burden.

Intensification means more capacity on the same site, usually through multi-storey industrial, deck access, or a reduction in surface parking in favour of yard. It works where the site is deep enough for a ramp or a goods lift of the right capacity, and where the covenant strength of likely occupiers supports the build cost. Ramps eat footprint: a ramp to a first-floor service deck for articulated vehicles needs a long run at a shallow gradient, and on a constrained site the ramp consumes the capacity the extra floor was meant to deliver.

Co-location means industrial and residential on the same site. It is permitted in principle in some categories of industrial land and tightly restricted in others, so establish the designation of the site before designing anything.

Substitution means delivering replacement capacity elsewhere, secured by obligation, with the replacement provided before or at the same time as the loss. The evidence burden here is the hardest, because the receptor site has to be identified, deliverable and of equivalent capacity on every component in the table above.

Design-led capacity testing of the kind described in optimising site capacity under London Plan policy D3 is the right tool for all three, applied to industrial floorspace instead of to homes.

Designated locations and the tighter test

Designation drives everything. Strategic Industrial Locations carry the strictest protection, and non-industrial uses in them are expected to be refused other than small-scale ancillary provision. Locally significant sites carry a protection set by the borough, and non-designated industrial sites carry the weakest, though still meaningful, protection.

Three practical points follow.

Confirm the designation from the adopted local plan policies map and the London Plan, not from a site-finding platform or a planning history. Designations change at plan review and the boundaries are drawn more tightly than people assume.

Where a site straddles a designation boundary, the test applies to the designated part and the arithmetic has to be presented separately for it.

Where the borough sits in a category that limits the release of industrial land, the no net loss requirement is the start of the analysis rather than the end, because the borough's own plan may require capacity to be provided rather than merely retained.

Servicing and amenity in a co-located scheme

Co-location fails on servicing far more often than on principle.

Separate the two uses at ground level completely. A shared vehicle access between an industrial yard and residential parking generates conflict that no management plan resolves. Separate accesses, separate pedestrian routes, and a service yard that no resident has to cross.

Acoustic separation has to work for a 24-hour operation, which means designing for night-time loading, refrigeration plant, reversing alarms and roller shutters. The agent of change principle puts the mitigation burden on the incoming sensitive use, so the residential element pays for the glazing, the ventilation strategy and the facade build-up. A Noise Impact Assessment assessing the industrial use at its permitted intensity, rather than at the intensity of whatever happens to occupy it today, is the document that makes or breaks the scheme.

Mechanical ventilation becomes unavoidable where windows cannot be opened, which then feeds overheating and energy.

Odour and air quality follow from the industrial use class. A scheme that permits B2 general industrial next to flats needs to show that any future B2 occupier can operate, not just that the current tenant can.

Where the residential element reaches the relevant height or scale, Planning Gateway One applies and a Fire Statement is required at application stage. A fire statement has to be prepared by someone with the necessary fire engineering competence, and an AI-assisted draft is a starting point for that person rather than a substitute.

Assembling the employment land evidence

Six documents carry the case, and the first is the one applicants most often skip.

1. A measured survey of the existing buildings and yard, with the capacity table filled in from it.
2. The planning history, including hours and noise conditions, because those define the capacity the policy protects.
3. An Employment Land Assessment setting the site in the borough's industrial land supply, using the borough's own evidence base and the London-wide demand studies rather than an in-house market view.
4. Marketing evidence where release is sought, covering a realistic period at realistic terms, with the agent's instructions attached. Marketing at a rent no industrial occupier would pay proves nothing.
5. Swept path analysis for the largest vehicle on both the existing and the proposed arrangement.
6. A delivery and servicing strategy, and on a substitution case, the obligation structure and the receptor site evidence.

Write the conclusion as a comparison rather than as an assertion. "The scheme provides 7,500 square metres against 6,000 square metres existing" invites the capacity question. "The scheme provides 7,500 square metres at 8.5 metres clear height with a 25 metre yard, against 6,000 square metres at 9 metres with a 32 metre yard, and the net capacity position is set out in Table 3" answers it.

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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.