Last month planning minister Nick Boles caused uproar when he stated that the amount of land built on in the England should increase by a third from 9% to 12%. I believe we should be turning our attentions to boarded up Britain, rather than developing more land, to help solve our housing crisis.

No matter where you look today you'll find an empty building. Homes, pubs, warehouses and mills abandoned are vacant and left to rot. You can't escape it on the high street; the UK town centre vacancy rate hit 11% in October, according to data from the British Retail Consortium. That's more than one in 10 shops now standing empty. We should transform these areas into affordable developments, leaving the greenbelt untouched.

Over the next 20 years more than 230,000 households will be formed each year. To cope with this increased demand around 250,000 homes need to be built every year. Critics argue that brownfield land and empty buildings can't be the answer because there isn't enough available to cope, but if you look at the figures closely there is enough brownfield land to build 1.5 million homes. Figures released by charity Empty Homes this winter showed that the number of homes in England now stands at 710,140. That's more than 2.2m existing homes, not to mention the vacant offices and retail spaces which can be transformed into residential housing.

Added together, these boarded up and brownfield sites could provide enough housing to cope with nearly nine years of rising demand and make up for past under-supply – not quite the 5m homes needed by 2033, but enough to keep the argument about greenbelt development at bay for a decade while tacking dereliction.

Boles' argument that the built environment can be more beautiful than nature is divisive. What cannot be denied is that the abandoned, unused and unloved buildings in town and city centres aren't pretty. We started BoardedUpBritain.com in a bid to draw attention to these buildings, so the public has a platform to shout about the empty buildings in their area and – through the power of the crowd and with the help of social media – put pressure on property owners to do something about them.

Despite some local authorities aiming to increase the council tax on empty properties, there are few real deterrents for landowners to do anything productive with their assets. It means the owners can just sit on these buildings until prices start to rise, and by land banking they also keep the prices of the current housing stock artificially high which is in their best interest.

We want to take a 'use it or lose it' stance. Why have a building sat there when it could be transformed into something more useful? Saltford Court, a tower block in Ancoats, Manchester was abandoned and unused after Manchester council closed it in the 1990s. A private developer purchased the building in 2006 but has failed to do anything with it since. Residents want change; it could be made into more than 100 much-needed apartments which could be brought on to market at an affordable price.

But it's not just private owners who are letting land and buildings go to waste. The brownfield land owned by the public sector is more than twice the size of Leicester. If this was sold on to developers who had a time limit to complete a housing development, it would raise money for local authorities and be a quick way of getting Britain building.

It's clear that we need to build more houses, but turning to the greenbelt and development on new land should be a very last resort. This issue shouldn't even be raised until we've used all the brownfield land we have.

Matthew Dyas is founder of BoardedUpBritain.com, a database of empty, derelict and boarded up buildings. Follow him on Twitter: @BoardedBritain

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