THE recession is bringing down the price of houses and flats from their over-inflated peak. It's a natural correction, but it is going to devastate housing supply at a time that we desperately need more homes.

In a timely move, Bristol's planners are calling on us to identify potential housing opportunities within the city boundaries – a chance for us all to scout our neighbourhoods for ideas.

Are we missing a trick not making the most of existing space? Are we able to find more space within the city to help reduce the need to reach out into the countryside? Can we intensify, and at the same time improve, some of those low density housing estates that we built since the war?

It is too easy to say there is any single solution to the massive challenge with which we are faced but with imagination I believe we can meet most of our needs on land and in buildings within the urban area, and on previously developed or under-developed land.

We need to look for both small and large opportunities. Check out the space above shops in your high street. Are they full of cardboard boxes or are they housing people?

At the other end of the scale, it seems mad to me that our great urban supermarkets are surrounded with swathes of black tarmac that contribute to the city and global warming. The airspace above these massive stores and acres of parking has value as a potential mixed use development. Can we build penthouses on the top of multi-storey car parks?

There are plenty of other areas of excessive tarmac or concrete that could be exploited. The Ashley Vale Self-Build Co-operative in St Werburghs is an extraordinary example of imagination and determination bringing family houses to an unlikely site and strengthening the St Werburghs community in the process.

Eight years ago, a group of local residents concerned about the future of a former scaffolding yard formed an action group to purchase and redevelop the site for the benefit of the community.

They brought together a group of 20 or so families who wanted to build their own homes and a housing association to provide some affordable housing to rent. The result may not win any architectural awards, but it is a remarkable and truly inspiring sustainable place.

Bristol Civic Society is keen to help the city with this process of finding opportunities. Apart from "living over the shop" and self-build potential, they suggest a raft of ideas that may spark specific examples in our minds.

Imagination should not be restricted. How about building at the ends of long gardens – with green roofs compensating for any loss of green on the ground? How about "living bridges", with houses on each side, as Bristol Bridge used to be – or even some floating homes?

As the Bristol Civic Society says, this sort of intensification need not involve high rise with all its problems, but what they describe as "distinctive, compact enrichment", whether it be in the posh or poorer areas. Sometimes it is much more attractive to have narrow streets that bring together communities rather than wide roads that divide.

There is just one month to come up with those ideas, some of which might have been starring you in the face for years. Any suggestions, obvious or wacky, will be welcomed by the city planners and by Bristol Civic Society who are co-ordinating proposals from their members across the city.

Get those thinking caps on!