In his speech to the Conservative Party Conference yesterday, Brokenshire hailed the publication of the new National Planning Policy Framework (NPPF) as evidence of the government’s commitment to increase housebuilding.
But he added: "We need to be smarter on how we use land and the space available. Prioritising brownfield but also looking at land that’s already been built on".
"That’s why I will publish proposals to permit people to build up on existing buildings rather than build out to use more precious land. And give councils greater powers to deliver the garden communities of the future", he said.
A statement issued by the Ministry for Housing, Communities and Local Government after the speech said that the government would be "introducing a new permitted development right to allow property owners to extend certain buildings upwards, while maintaining the character of residential and conservation areas and safeguarding people’s privacy".
The statement said that this would allow "more flexibility to extend upwards on existing blocks of flats, shops and offices, making better use of space by increasing housing density".
The revised NPPF includes new policy promoting upward extensions. It says planning policies and decisions should "support opportunities to use the airspace above existing residential and commercial premises for new homes".
In 2016, the then Department for Communities and Local Government (DCLG) and the mayor of London consulted on options for "incentivising greater 'building up'" across London.
The consultation proposed that upward extensions could be built up to the roofline of an adjoining building through a new permitted development right, local development orders, or London Plan policies.
But, responding to the consultation on the issue, the DCLG later said that more than half of consultation responses believed a "one-size-fits-all" permitted development right to be "unworkable" and the plan was abandoned in favour of the new NPPF policy.
Away from upwards extensions, yesterday's statement also said that the government would be "championing ambitious councils keen to make new garden communities a central part of their plans for housing and economic growth".
It said that the government would produce "clearer guidance to give more certainty for communities when land is needed to make a new town a reality".
The statement also said that local authorities will "receive additional freedom to make the most of existing brownfield land and dispose of surplus land that could instead accommodate new homes".
The government will consult on these new measures "in due course", the statement said.
Responding to the announcement, Royal Town Planning Institute chief executive Victoria Hills said: "Densification of built-up areas can bring about much needed housing supply, but quality is as important as numbers. Blanket height extensions come with issues that have potentially serious impact on streetscape and people’s access to light. National policy can provide a favourable steer, but local communities should be able to set standards which enable higher buildings to make a positive contribution to housing supply."
Melanie Leech, chief executive of lobby group the British Property Federation, said: "Making it easier to build up on an existing building, so that an underused house becomes several flats, is a good example of an initiative which should encourage local authorities to think creatively about solutions in their area.
"Communities however will only accept development at greater density if local services and infrastructure can adequately support the growing population of a particular area. Inadequate planning or funding of school places, healthcare or leisure facilities will inevitably create animosity towards proposed development".