Designing four prototype villas with areas ranging between 500~1000 sqm in KSA involves creating robust and efficient structures using hollow blocks and solid slabs. Each villa comprises a ground floor, first floor, roof annex, and roof deck. The design focuses on optimizing structural integrity while accommodating local environmental conditions and building codes. Hollow blocks provide excellent thermal insulation and reduce overall building weight, while solid slabs offer durability and support for multiple floors.