Envelope First: A Review of Building Envelope Performance, Saudi Building Code Energy Requirements and Cooling Demand in Saudi Homes, with a Tiered Pathway towards Near-Zero-Energy Housing

Homes are the largest single user of electricity in Saudi Arabia, and most of that electricity runs air-conditioning. In 2024 the residential sector took about 47% of national consumption, and air-conditioning accounts for roughly two-thirds of household use. This review examines how the building envelope and the energy requirements of the Saudi Building Code (SBC 601 and SBC 602) shape cooling demand in Saudi villas and apartments, and in what order improvements should be made. A scoping search of OpenAlex on 6 November 2026 returned 700 records on Saudi residential energy, with annual output rising more than fourfold between 2015 and 2025. Targeted searches and citation tracking gave a final base of 44 peer-reviewed sources, mostly Saudi and Gulf simulation and field studies, read alongside official statistics. Roof and wall insulation give the largest single savings, and roofs, exposed columns and slab edges carry a large share of the cooling load in concrete-frame houses. Glazing and shading matter mainly for peak gains and comfort; their annual effect is smaller. Code compliance reduces modelled energy use intensity by about 5–25%, combined envelope packages by about 25–68%, and adding rooftop photovoltaics brings calibrated villas close to near-zero energy. Occupant setpoints and schedules can move results as much as some envelope measures. The paper proposes an Envelope-First Residential Pathway with five cost and impact tiers, separate routes for villas and apartments, and eleven measurable indicators, from energy use intensity and peak demand to U-values, air leakage and net grid import. A research agenda closes the review.