Housebuilders have warned that issues with biodiversity net gain rules are slowing home delivery, with 84% continuing to find the legislation challenging two years after its introduction, according to the Home Builders Federation. HBF’s new report, based on a survey of HBF members undertaken in early 2026, highlights the difficulties surrounding BNG legislation. HBF said the rules, dictating that sites achieve a 10% improvement in BNG, were “having a clear and growing impact on development viability and housing delivery, particularly on smaller sites”.