England faces a "housing time bomb" with 3.5 million extra households needing accommodation by 2021, a report has found.
The Town and Country Planning Association study says 200,000 new homes must be built each year to prevent demand continuing to outstrip supply.
Falling death rates, smaller households, rising divorce rates and immigration will all contribute to the projected increase, the report says.
TCPA director Gideon Amos said: "Much as with the looming pension crisis, we are facing a serious shortfall in the future unless we act now to provide more homes for the next generation."
In 2004-5 more than 154,000 homes were built in England, according to official figures.
The government has committed itself to building an additional 1.1 million homes in the South East by 2016.