The man charged with leading Birmingham's regeneration has urged neighbouring authorities to look at their green belt land for development and "wake up" to the major housing crisis facing the sub-region.
Waheed Nazir, director of planning and regeneration at Birmingham City Council, said areas such as Birmingham, Coventry and Solihull were facing an "incredible challenge" unless they addressed the issue of providing enough homes for the expanding population.
He said: "Our biggest challenge is accepting the city is bursting at the seems and the release of the green belt to the north of Birmingham has had its fair share of respondents including 15,000 individual letters to me.
"Some of the concerns raised are reasonable. The infrastructure to support this growth must be put in place but it's trying to manage that with the viability of the market we are in.
"I would like to be building 80 to 100 homes per hectare but the reality is the market cannot sustain more than 30 or 40.
"Depending on what methodology you use, 80,000 is the minimum number of homes which need to be built in Birmingham but this could grow up to 120,000.
"Unless we deal with this, and we're serious about it, the housing crisis is only going to get worse.
"To be frank, Coventry, Solihull, Bromsgrove, all of them are going to have to look at their green belt because we have a major housing crisis in the sub region. Unless we wake up and start dealing with this, we're going to have an incredible challenge."
Mr Nazir was speaking at a 'Future Cities' seminar as part of the British Council for Offices Annual Conference in Birmingham.
He said the city's population was expected to increase by 150,000 by 2031, which would require at least 80,000 new homes, however Birmingham only has enough brownfield land for 45,000 and up 10,000 homes on green belt.
Circa 400 hectares of employment land is also required but Birmingham only has capacity for 250 more hectares
Last autumn, plans were revealed for a new 5,000-strong housing estate with three schools in Walmley, Sutton Coldfield, while in November residents in Foxlydiate, Worcestershire, vowed to fight plans for 3,000 homes on green belt land.
Mr Nazir said planners were keen to bring family living back to the city centre on the back of successful schemes in area such as the Jewellery Quarter.
"We're working on densities for the city centre of 70 to 90 per hectare which is a lot higher than in suburban areas," he added.
"When you get into some of the more suburban and neighbourhood areas and brownfield sites, you're being very naive if you think we would looking at 90 per hectare - it's not going to happen.
"We have a lot of viability issues. We're going to struggle to get more than 40 per hectare as the market will not deliver it. Developers have already said that 40 homes per hectare in suburban areas is too high."