Housebuilder Vistry has warned first-half profits will be sharply lower as it looks to boost flagging demand amid the Iran war with incentives and discounts. The group said house sales have eased back in recent weeks due to uncertainty caused by the Middle East conflict, though year to date open market sales remain around 30% higher year on year. It is also seeing material prices start to rise and labour costs increase, which it said is set to continue into the second half. Vistry said it was boosting the use of incentives and discounts, in particular on low-margin properties and developments near to completion. “Primarily due to the up-front profit impact of the actions to accelerate cash generation … we expect first-half profit to be significantly lower than the prior year,” it cautioned.…