A Barnet basement appeal has succeeded after councillors rejected their officers’ recommendation to approve extensive excavation beneath a locally listed house in Hampstead Garden Suburb. But the applicant’s attempt to recover appeal costs has failed.
Inspector N Perrins allowed appeal 6013253 on 28 October 2026, granting planning permission for a basement, lightwells, a skylight and alterations to the rear terrace and doors at a house in Wellgarth Road, North London. A separate costs decision on the same date refused a full award against the London Borough of Barnet.
This pairing matters for planning committees and applicants. An Inspector can disagree with elected members and allow development without finding that the council behaved unreasonably. The standards for granting planning permission and awarding costs are not the same.
What the Barnet basement appeal involved
The house was built in 1912 to a Neo-Georgian design by Cowles-Voysey. It occupies a prominent junction plot within the Hampstead Garden Suburb Conservation Area and was included on Barnet’s local heritage list in 2020. Its architectural contribution lies principally in the way the house looks, its proportions and how it sits within the garden and surrounding street.
The basement would increase the property’s internal floorspace by more than 60%. That is a substantial addition, but almost all of the work would be entirely below ground. It would extend beneath the existing house and a short distance outside its walls, including beneath an existing paved rear terrace. The visible consequences would be limited to two flush-glazed rooflights in the terrace and modest changes to the doors.
Planning officers had recommended approval, and the council’s heritage officer did not object. However, the planning committee refused permission because members considered the basement too large for the character of the house and conservation area. The Hampstead Garden Suburb Trust had expressed a reasoned objection based partly on the area’s special planning history and the traditional relationship between houses and their gardens.
That was the starting point for the Barnet basement appeal. The Inspector had to decide whether the extra floorspace would damage the conservation area’s appearance or the significance of the house as a non-designated heritage asset.
Why the Inspector found no heritage harm
Inspector Perrins acknowledged that the design guidance for Hampstead Garden Suburb does not look only at exterior appearance. The scale of internal accommodation can also be relevant. The guidance generally favours basements within the house’s footprint, while allowing limited exceptions for larger houses with generous gardens where the details justify them.
In this case, the Inspector found that the modest front projection would remain below ground and invisible from the street. The rear projection would extend beneath an existing terrace rather than remove garden planting or introduce a new structure above ground. The height, roofscape, principal elevations and proportions of the house would not change.
The appellant’s evidence indicated a rear projection of approximately 3.7 metres, within the four-metre guideline for a detached dwelling in the council’s newer supplementary planning document. The proposal also involved a single basement storey and would leave more than half the rear garden length unexcavated. These considerations supported a finding that the addition was subordinate to the house.
The Barnet basement appeal therefore succeeded on a site-specific heritage judgement, not because basements are automatically acceptable in conservation areas. The Inspector concluded that the scheme would preserve the area’s character and appearance and would not harm the locally listed building. Planning Geek’s basement planning permission guide explains the separate planning, construction and other controls that can apply to excavation projects.
Why the Barnet basement appeal costs claim failed
The applicant sought a full award of costs on the basis that the planning committee had refused a scheme which officers and the heritage officer considered acceptable. In this Barnet basement appeal, planning costs were not an automatic consequence of success. The applying party must show unreasonable behaviour that caused unnecessary or wasted expense during the appeal.
In the separate costs decision, Inspector Perrins recognised that members had relied on the Hampstead Garden Suburb Trust’s specialist objection and the council’s design guidance. Although the Inspector disagreed with the outcome, the conservation and heritage questions involved professional and planning judgement on which reasonable people could differ.
The costs decision stated: Members were entitled to prefer that view to their officers’ advice.
This is a quotation from the Planning Inspectorate’s separate costs decision, reproduced under the Open Government Licence.
There were weaknesses in the council’s defence. Its costs response raised rooflights, which were not part of the formal reason for refusal, and appeared to misstate the heritage officer’s later position. Nevertheless, the reason for refusal itself had been supported by material available to the committee when it voted.
For that reason, the Barnet basement appeal was allowed, but the Inspector refused to order the council to pay the appellant’s costs. Winning the planning arguments on appeal was not enough to prove unreasonable council behaviour.
Planning Geek’s guide to planning appeal costs explains the evidential threshold, the distinction between substantive and procedural costs, and what an applicant needs to demonstrate.
Conditions still protect neighbours and the drainage system
The Inspector considered concerns about flood risk, ground movement, construction noise and trees. The site lies in Flood Zone 1 but within a critical drainage area, so the scheme was supported by a flood risk assessment and basement impact assessment. The Lead Local Flood Authority raised no objection, subject to a surface water drainage scheme.
There were also ground investigation materials and structural drawings addressing temporary works and underpinning, and the Inspector noted that the structural integrity of the house and neighbouring buildings during construction was separately controlled through building regulations and other legislation. Approval did not remove those responsibilities.
Conditions require a demolition and construction management plan, controls on working hours, tree protection, landscaping, drainage and details of ground levels and matching materials. The Inspector considered that these conditions could address the identified construction and environmental concerns without justifying refusal on heritage grounds.
The lesson for planning committees after this appeal
The Barnet basement appeal provides a useful distinction at a time when England is changing the national approach to committee delegation. Councillors are not legally required to follow an officer’s recommendation, but they should identify defensible planning reasons and supporting evidence if they take a different view.
Where an Inspector later reaches a different judgement about heritage impact, that is not proof that the committee acted unreasonably. Equally, an officer recommendation does not shield a council from a costs award if its decision lacks evidence or its appeal behaviour wastes another party’s expense.
The committee decision in this case was made in April 2026, before the new national delegation arrangements were due to take effect. It should not be used as evidence that the same category of application would necessarily be referred to committee under a later scheme. Planning Geek’s national scheme of delegation guide explains the separate changes to committee decision-making.
This was one planning appeal and one separate costs determination, not a court ruling establishing a new test. The decision illustrates why a strong planning case and a strong claim for appeal costs need to be assessed independently.
Appeal and costs decisions
Read the official Planning Inspectorate appeal record, including the separate costs decision, and the contemporary planning committee report. The decision is also available via AppealBase.
0 Comments