Advances in building techniques have made it possible to build additional storeys on many blocks of flats. Such developments may not be popular with existing residents but, as a High Court case showed, the pressure on housing stocks is such that planning permission for them is frequently forthcoming.

The case concerned planning consent granted for a one-storey upward extension to a four-storey block. The development, which included five exterior elevators, would provide 16 additional residential units in an area of high housing demand. The block's residents' association was united in opposing the scheme.

The association's core concerns were that the extension could not be safely built and that top-floor residents might have to vacate their homes during the construction works. A local authority planning officer's report, however, praised the proposal as a high-quality, attractive development of appropriate scale. It stated that there would be no harm to a nearby conservation area, that the project accorded with the local development plan and that, despite some loss of sunlight, the effect on local residents' amenities would be negligible to minor.

In rejecting the association's judicial review challenge to the planning permission, the Court found that the council had properly addressed the issue of whether the block was structurally capable of accommodating an additional storey. It was entitled to conclude that structural issues would be more appropriately dealt with under the building control, rather than the planning, regime.

The developer's representatives had expressed confidence that solutions to any structural challenges could and would be found and that temporary displacement of existing top-floor residents was highly unlikely. That chimed with the professional experience of planning officers and the council was not required to insist on the developer submitting a full structural survey.