In an interim management statement, Bellway said site visitor levels and reservation rates continued to outperform expectations, with weekly sales between February 1-May 31 up 19% on a year ago (attained from 210 sites compared to 195 last year).

"The target set at the beginning of the financial year of achieving 5% volume growth is now secure, subject to build delivery, and the Board is therefore confident that legal completions for the year ending July 31, 2012 should exceed those achieved last year by around 300 units," said Bellway.

Some 1,600 reservations have been taken for completion in 2012/13.

The average selling price since February 1 is £190,400 – an increase of 5% compared to the same period last year, primarily due to a combination of the ongoing contribution of higher value units from the group’s divisions in the London market, together with a greater proportion of private reservations.

An increasing proportion of completions from new sites, where margins are typically in excess of 20%, should result in the group producing an operating margin of at least 11% for the full year.

The Group said the Government’s NewBuy mortgage indemnity guarantee scheme had contributed 90 reservations in the 11 weeks since its launch.