At its results announcement on Wednesday, the company said its pre-tax profit had risen 21% to £53.6m in the year to 29 February.
Private house sales were up 2% to 4355, but average selling price rose 15% to £104 700.
Nigel Fee, recently appointed managing director, said the price increase was because of a combination of house-price inflation and the fact that the firm is building larger three- and four-bedroom houses.
Fee said the housing market should remain steady for the next two years at least, but added: “It is not the boom market that lots of people talk about.”
Fee also said Westbury was keen to take part in further consolidation: “Size is an issue. We would like to be bigger.”