HOUSING starts in Western Australia fell 10.1 per cent in September, following a 13.8 per cent climb in the previous quarter, according to figures published by the Australian Bureau of Statistics. Master Builders Australia chief economist Peter Jones said there were two factors affecting the market in WA. "Perth is suffering severe constraints, in terms of materials and labour, and the other factor at play is affordability, (which) has now worsened significantly," he said.