Nearly 460,000 homes will have to be built in the South West over the next 20 years to keep up with demand, the South West Regional Assembly says.
Critics say 25,000 new houses are needed in the region each year
The housing figures for Devon, Cornwall, Somerset, Dorset, Wiltshire and Gloucestershire are included in its draft Regional Spatial Strategy.
But critics have said 500,000 more new homes actually need to be built by 2026 because of population increases.
A 12-week public consultation period on the strategy runs until August.
Issues from housing to transport, waste treatment and economic development will be considered by the assembly as it sets out its draft strategy.
It wants to know what people think the South West will be like in 2026 and what planning initiatives they would like to see in place between now and then.
The strategy aims to ensure future planning decisions consider the balance between development and tradition and rural and city life.
In terms of housing, the strategy says 23,000 new homes are needed per year.
But this has been disputed by South West Housing Initiative, a group representing the region's biggest house-builders, housing associations, employers and professions involved in property and planning.
It said the region must deliver at least 25,000 new homes per year for the next 20 years, to tackle affordability gaps between average house prices and average incomes.
Initiative Co-ordinator Martin Willey said: "Latest government figures show that the South West has only been delivering about 17,000 new homes per year, while the region is growing by more than 25,000 households per year."
The assembly said that the draft strategy recognised that the South West was one of the fastest growing of all the English regions, and the main thrust behind the strategy was the importance of creating a sustainable region.