The key considerations for structural engineering in loft conversions and home extensions include load-bearing walls, foundations, and roofing. Load-bearing walls support the weight of the structure above them and are typically located along the perimeter of the building. The foundations of a home provide a sturdy base and support the weight of the walls, floors, and roof. The roof protects the interior of the home and must be properly supported by the walls and ceiling below. It is important to work with a qualified structural engineer to ensure that these elements are properly designed and installed.