Councillors have agreed plans to build more than 47,000 homes in Cornwall, the equivalent of four towns the size of Falmouth being built by 2030.
Cornish residents will now be consulted on the plans.
The contoversial plan was agreed after a vote at County Hall, with 62 votes for and to 31 against, with 10 abstentions.
This plan will be the cornerstone of Cornwall Council’s planning strategy for the next 17 years.
The 47,500 includes existing permissions, and houses that have been built between 2010 and the present day will be deducted from the headline figure and not added.
This means that 27,000 of the homes have already been granted planning permission, of which over 7,000 have been built. That leaves 20,500 dwellings for the next 17 years.
Councillor Andrew Wallis said that most if not all of the process and debate has been on the number of dwellings within this plan.
Adding that if these numbers are set too low, the plan will be rejected by Government.
He said: "This would leave Cornwall without that all important plan. The advice given is a plan with numbers less than 47,500 would be in grave danger of falling foul of the Government rules. We may not like it, but it is the Government's ball, and they set the game.
"The government guidance states the headline figure should be evidenced using a Strategic Housing Market Needs Assessment or SHMNA unless better evidence is available these should start with data from the Office of National Statistics.
"There is currently no other defensible evidence and the 47,500 is the lowest figure that aligns with this guidance and our officers feel they can robustly defend this figure.
"Local Plans elsewhere have been rejected for proposing as little as one per cent and two per cent lower than ONS projections.
"Out of the 64 other Local Authority Local Plans, only three have managed to defend a lower figure, and all these were told an early review was to be undertaken on those numbers. Interestingly, no Local Plan in the last year has managed to defend a plan with lower numbers."
A bid to lower the number to around 33,000 by Conservative councillors at the authority was roundly defeated, with Cllr Fiona Ferguson calling the decision, "A bad day for Cornwall and a disaster in the making".
She said: "The manner in which the Office for National Statistics (ONS) figures are generally used for the assessment of housing need does not provide an accurate picture of the future population of Cornwall. This has been shown time and again. It should come as no surprise because our population growth is almost exclusively as a result of net inward migration, which is far more difficult to estimate than natural growth.
"The housing report prepared by the council’s consultants predicts that between 47,300 and 71,980 dwellings will be needed.
"Unfortunately the approach taken by Cornwall council in not challenging the consultant’s figures will allow the planning inspector who examines their plan the opportunity to ask why he/she should not require the higher number.
"Recent examples of local authorities that have submitted evidence with a range of figures is that the inspector will require the top end of the range and not the bottom.
"The net result of today’s decision by councillors voting for 47,500 is that they will open the door for the inspector to reject the plan as unsound and/or require a figure closer to 71,980."
Cllr Dick Cole of Mebyon Kernow said that the MK group also did not support the target of 47,500.
He said: "In the final vote, we abstained because no alternative proposal had been tabled, which could be supported, and a consultation document needed to be agreed.
"During this consultation, the MK group will continue to challenge the Coalition Government to allow Cornwall Council to set its own housing target – and to work up detailed evidence for a sustainable lower housing target which we will present to the public examination."