NHBC chief executive Imtiaz Farookhi said the increase in applications in May reflected improving weather after housing starts were stymied earlier in the year.
He said: "The recovery in May registrations seems to confirm that bad weather conditions were largely responsible for the drop in housebuilding activity earlier this year."
England and Northern Ireland were responsible for the increase in housing applications, up 11% and 25% respectively. Scotland was down 29% and Wales fell 7%.
New-build completions in the private and public sectors fell 5% from 13,541 last May to 12,887 this year. The NHBC said that on average 535 new homes were sold each day during May, down 6% on the same period last year.
Cheshire had England's biggest percentage increase in new-build applications, up 176% from 156 last May to 431 in May this year. Nottinghamshire (up 164% to 317) and Cumbria (up 139% to 110) also enjoyed large increases.