Principality Building Society saw a modest increase in its retail mortgage book, with a £2m rise to £11.3bn over the six months to June. Principality Building Society also served 3,195 first-time buyers, down from 4,033 last year. It said the lower number reflected affordability pressures in the housing market but said it remained focused on lending sustainably. Nevertheless, the mutual said its loan portfolios remained strong, reflecting its “prudent lending criteria, credit quality and underwriting standards”. The rate of arrears across its book was 0.56%, flat on December and lower than the industry average of 0.91%.