Proposed Two-Story Residential Building with Two-Level Basement

Project Details

This project involves the comprehensive structural design and engineering for a high-end residential property featuring two stories of living space above ground and an extensive two-level subterranean basement. A significant component of the design is the integration of a reinforced concrete swimming pool within the lower levels, which necessitated specialized retaining wall analysis and geotechnical considerations. The structural assembly utilizes a hybrid material approach to balance strength and efficiency. The primary framework consists of high-strength structural steel beams (UKB and UKC sections in grades S275 and S235) and SHS steel columns, which provide robust support for the building’s large spans and significant dead loads. This is integrated with a timber-framed flooring and roof system utilizing C24 and C16 strength class timber joists and rafters. The design process included rigorous structural analysis to ensure safety against environmental and lateral loads. Calculations were performed in accordance with Eurocodes (EN1991, EN1992, EN1993, EN1997) and British Standards (BS5268), accounting for characteristic ground snow loads and peak wind velocity pressures based on the property’s location in London. The two-level basement is secured by propped cantilever retaining walls with 300mm thick stems and bases, engineered to perform reliably within medium-dense well-graded sand with a characteristic shear resistance angle of 30 degrees. Every critical structural member underwent detailed checks for bending stress, shear force, and vertical deflection to ensure compliance with stringent building safety limits.

Role

Structural Engineer/Designer

Services Provided

The scope of services included the preparation of structural analysis and structural plans for the proposed structure. Structural analysis considered loading evaluations for wind, snow, seismic, dead, and live loads, together with the structural analysis and design calculations of all primary structural components, including foundations, columns, beams, floor joists/slabs, load-bearing walls, and rafters/trusses. The work involved verifying that all structural elements were capable of safely resisting applicable gravity and lateral forces in accordance with the governing building code and project requirements. The services also included the preparation of structural drawings consisting of foundation plans, floor framing plans, roof framing plans, schedules of footings, columns, beams, floor joists, and rafters, as well as structural details and connection details. General structural notes and specifications were also prepared to clearly communicate the design intent and support permitting, coordination, and accurate construction implementation.