Newbuild housing cannot provide enough homes needed in London to help overcome today's housing crisis. Better use has to be made of existing buildings and building upwards to add extra storeys.

The Builders Merchants Federation (BMF) was responding to a consultation seeking views on proposals to enable London to “build up” more easily to reduce the pressure to “build out”, while at the same time protecting the Green Belt.

Planning ought to be a system where development is enabled and managed, rather than just being about development control, the BMF emphasised. Policy that accelerates the completion of much-needed, properly considered, small-scale housing is very welcome to merchants, the BMF said.

According to figures published jointly by the Minister for Housing and the Mayor of London, 49,000 extra homes per year are required to narrow the gap between housing demand and supply. Yet on average, only 25,000 additional units have been completed each year since 2008. And of these, fewer than 2% were as a result of projects that included some element of upward extension work.

John Newcomb, managing director of the BMF, said: “Nobody wants a repeat of bad high-rise housing from the past, but the BMF believes better use can be made of existing buildings. As these figures show, there is scope to dramatically increase the number of new homes. Allowing London property to be extended upwards, for limited number of storeys, up to the height of adjoining buildings, without needing prior approval, is a good way to do so. It is not the single solution to today’s housing crisis but it is a good one, worth pursuing.”

Mr Newcomb noted there was consensus among the five candidates vying to be elected as the new Mayor of London on 5 May that housing delivery is the number one policy priority.

The Department for Communities and Local Government set out three possible policy options: firstly, a new Permitted Development Right, with a prior approval, to add extra storeys on existing buildings; allowing London boroughs to use existing powers under Local Development Orders for extra storeys in specific areas, or for specific buildings; or the Mayor could introduce new policies for extra storeys when reviewing the London Plan.

Of these options, the BMF favours a new Permitted Development Right. In outer London Boroughs, there are plenty of shopping parades, above which is (at least) one storey of flats or maisonettes. These are ideally suitable sites to allow additional storeys to be built, the BMF said.

The BMF concluded its remarks by reminding politicians that demand for housing is far outstripping supply. The concept of enabling London to “build up” more easily should be introduced as quickly and smoothly as possible to allow owner-occupiers and landlords to complete un-contentious projects that conform to the rules.