Vision Energy was appointed to deliver full SAP Calculations for a new infill residential development comprising four three-storey terraced homes. The project required compliance with Part L 2021 on a constrained urban site. A fabric-first approach was adopted, using enhanced insulation, triple-glazed windows, and mechanical ventilation with heat recovery (MVHR). Heat pump technology was integrated for space heating and domestic hot water, with roof-mounted PV reducing regulated emissions further.