However, Johnson pledged to “give people the space they need to live” after research revealed that less than a quarter of homes built through permitted developments meet national space standards.
Research conducted for the Ministry of Housing, Communities and Local Government (MHCLG) found studio flats measuring just 16m2 in several permitted development (PD) schemes, while natural light was often far more limited.
The issue was raised by Housing, Communities and Local Government Committee chairman Clive Betts MP at prime minister’s questions.
He asked Johnson if he was aware of the report’s findings about the size of the properties built.
“To put this in context for the prime minister, 16 square metres is just about the size of the base of the ministerial limousine that he gets driven around in each day,” Betts said.
“Will he now change the rules and ensure that we never again allow slums to be built and people to be asked to live in a space as small as his ministerial car?”
Johnson replied: “I was proud as Mayor of London to change the London plan to ensure that we went for Parker Morris plus 10 per cent for our space standards.
“We will ensure that we not only build back better and more beautifully, but that we give people the space they need to live and grow in the homes that we will build.”
Key government policy
Change of use PD rights is one of the government’s primary policies for increasing the number of homes built where buildings can be converted into residential properties without planning permission.
However, concerns about the standard of properties from these schemes were supported by the MHCLG research conducted by UCL and the University of Liverpool.
The institutions found in some measures PD buildings were on par with those built with planning permission, but in crucial issues around internal design they often fell well below standard.
“Overall, only 22.1 per cent of dwelling units created through PD would meet the nationally described space standards (NDSS), compared to 73.4 per cent of units created through full planning permission,” the report said.
“In many cases, the planning permission units were only slightly below the suggested standard, whereas the PD units were significantly below (for example, studio flats of just 16m2 each were found in a number of different PD schemes).”
It was notable that 69 per cent of units created through PD were studios or one bedroom compared to 44 per cent through planning permission units.
Where natural light was considered, 72 per cent of PD units only had single aspect windows, while this was limited to 30 per cent through planning permission.
Additionally, two thirds of planning permission units had from dual or triple aspect windows compared to only 27 per cent of PD units.
“We found ten units which appeared to have no windows at all – no such units were found in schemes consented through planning permission,” the report continued.
“In some cases, PD schemes had layouts which would reduce access to natural light, for example, contrived layouts to enable the unit to have a window which was then far removed from the main usable floorspace of the unit.”
Developers open to standards
While developers valued PD for its certainty and speed compared to a full planning application, some questioned by the researchers appeared open to some standards being applied as long as these did not unduly delay the consent.
“Requiring higher standards (such as compliance with NDSS) could reduce the number of housing units delivered, particularly in those locations with the most marginal development viability,” the report said.
“Higher spec units may, however, be a better long-term investment, given potential future resale value and obsolescence of the residential conversions.”