Westminster office-to-flat appeals win three homes

Westminster office-to-flat appeals have succeeded for three new homes on Bolsover Street after a planning inspector found that the building’s historic residential character and quieter street setting satisfied the city’s strict office-protection policy. Two separate refusals were overturned in a combined decision dated 8th October 2026.

The proposals involve converting the lower ground and ground floors at 53 Bolsover Street into a one-bedroom flat and a studio, together with converting the first floor into a further dwelling. The building is inside central London’s Central Activities Zone and the Harley Street Conservation Area, where loss of employment space normally receives close scrutiny.

The decision turns on a subtle but important interpretation of the recently adopted Westminster City Plan 2026: a street can be predominantly residential in character even where some offices and shops remain. The inspector also accepted evidence that the building had originally been a house, allowing residential use to be reinstated rather than introduced as a wholly new activity.

Westminster office-to-flat appeals: two permissions

The Westminster office-to-flat appeals concerned two applications at the same address. Appeal A, reference 6010775, concerned the lower ground and ground floors, application 25/04830/FULL. Appeal B, reference 6010768, concerned the first floor, application 25/04411/FULL. Both were brought by JBA 53 Ltd against the City of Westminster Council under section 78 of the Town and Country Planning Act 1990.

The appeals were considered together because the refusal reasons concerned the same building and broadly the same policy issues. A Planning Inspectorate representative visited the site on 8th September 2026 and prepared a recommendation that was considered by inspector F Harrison before the decision was issued.

Both proposals were allowed subject to separate condition schedules. The approvals together allow three self-contained residential units, not a wholesale conversion of every floor in the building and not an unrestricted change of all nearby offices into housing. Their scope remains defined by the individual application drawings and permissions.

This was an ordinary planning appeal against refusals, rather than a determination of permitted development prior approval under Class MA. That distinction matters because local office-protection policy, the original use of the property and the area’s character formed the core planning balance.

How Westminster’s office-protection policy was applied

The Westminster office-to-flat appeals turned on Policy 17 of the Westminster City Plan 2026, which protects office space in the Central Activities Zone.

It permits the net loss of office floorspace to residential use only in parts of the zone which are predominantly residential in character and where the proposal reinstates an original residential use. Both limbs had to be satisfied.

The council’s position was that the applications represented an unacceptable loss of employment space. The inspector assessed the immediate street’s physical character and how it was experienced, not simply a count of the buildings in each use class. The nearby Euston Road and Great Portland Street corridors were busier and more commercial than Bolsover Street itself.

Although there were commercial units close to the junction with Great Portland Street, the inspector found that much of the immediate setting included residential properties. The relatively calm activity, buildings with a domestic appearance and limited scale of commercial movement contributed to an overall residential character.

That approach is noteworthy for mixed-use central locations. The presence of shops or offices does not necessarily prevent a street being described as predominantly residential, but the finding depends on the evidence and the characteristics of the precise locality. It is not a numerical exemption from employment-land policy.

The decision also referred to relevant London Plan policies protecting employment opportunities. The inspector nevertheless concluded that the specific proposals would not create an unacceptable loss of employment space because the Westminster policy criteria for an exceptional residential return had been met.

Original residential use provided the second test

The appellant relied on historical material, including the Survey of London, suggesting that the building was originally a pre-Victorian house. The council did not dispute that account, and the inspector saw no clear reason to reach a different conclusion. The proposal therefore restored an original residential use for the purposes of Policy 17.

This was not a finding that any building which resembles a house must be free to revert to housing. Documentary historical evidence was important. Other former residential buildings may still face different conservation, employment, amenity or planning constraints, and not every property in the Central Activities Zone will satisfy the area’s character test.

For an owner considering redevelopment of a townhouse now used as offices, archival plans, listing information, historic mapping and building records can be more than background detail. They may be central to the planning justification where local policy expressly asks whether a residential use would be reinstated.

The original-use question also needs to be distinguished from a lawful development certificate based on continuous use or an old planning permission. Here the inspector was applying an adopted planning policy about acceptable net loss of offices, not declaring that the current office accommodation had become residential by operation of law.

Conservation area, noise and parking conditions

The Westminster office-to-flat appeals also raised heritage questions because the building stands within the Harley Street Conservation Area. The inspector addressed the statutory duty to pay special attention to preserving or enhancing its character and appearance. The limited works, the traditional residential qualities of the area and the character of the building supported a finding of no conservation harm.

For the lower-ground and ground-floor conversion, the conditions include matching external materials, installing specified glazing before occupation and providing approved refuse and recycling storage. The first-floor permission has its own approved-plan and refuse-storage requirements. These details form part of the actual approvals and cannot be ignored after the appeal succeeds.

The inspector did not impose the suggested restrictions on construction hours, noise or parking beyond conditions considered necessary. There was no clear evidence of unacceptable noise, while building-regulations sound insulation and the highway authority’s parking-permit controls were separate considerations. Parking fears were not substantiated in the evidence to the degree required to justify a planning refusal.

The decision also recognised that a statutory biodiversity gain exemption applied to the particular schemes. It did not create an exemption for all office-to-residential conversions: eligibility must be tested against the exact statutory criteria and the relevant development proposal.

Practical implications for office-to-residential projects

The case demonstrates why a city-centre office-conversion proposal should be assessed against the precise local policy and the character of the street rather than only its position on a Central Activities Zone map. A good planning statement must explain both where the site sits and how its immediate surroundings function.

Where policy allows residential reinstatement, evidence of original use needs to be assembled early. A bare assertion that a building looks domestic may not be enough where archive records could settle the issue. Proposals should also deal with accommodation quality, heritage details, refuse facilities and potential effects on neighbouring occupiers.

A related but separate topic is the national permitted development route for certain commercial-to-residential changes under Class MA. That route has its own conditions, exclusions and prior approval matters. These Westminster applications were determined on their individual planning merits, so the appeal should not be reported as a precedent automatically expanding Class MA rights.

The decisions are published together under appeal reference 6010768, also covering 6010775. The Planning Inspectorate case record provides the official appeal route. For the wider English policy context, Planning Geek maintains Planning in England coverage.

In the Westminster office-to-flat appeals at Bolsover Street, the inspector found both the predominantly residential character test and the return to original residential use satisfied. Other central London properties will still need their own policy analysis, evidence and design response. The useful precedent is the reasoning, not a transferable permission for three flats elsewhere.