Demountable and Relocatable Steel Hotel Buildings for the Haramain Central Areas: Structural Performance of a Standardised 18-Storey Module and Design Guidelines for Reuse

This paper examines hotels and commercial buildings around the two Holy Mosques of Makkah and Madinah, which must be demolished in 10–20 years to make room for mosque precinct expansions, even though their reinforced-concrete (RC) frames are designed for 50 years or more. Instead of the current build–demolish–rebuild practice, the proposal is a set of identical, fully demountable steel buildings that can be unbolted, moved, and re-erected on a new site when a precinct is cleared. A reference module (18 storeys and 63.2 m above a permanent RC basement “dock”, on a 3 × 4 grid of 8 m bays) is derived from the stock of recent central-area hotels and analysed in COMSOL Multiphysics as a three-dimensional beam finite-element model with floor diaphragms, S355 sections and bolted connections, under gravity, SBC 301 wind and equivalent-lateral-force seismic actions and in free vibration. It is found that the bare moment-resisting frame satisfies the strength (utilisation 0.80) and seismic drift (0.0076) requirements but not the wind serviceability limit (inter-storey drift 1/209 > 1/400). Demountable CHS X-bracing in the two end bays of each long face reduces the roof sway under wind from 209 mm to 83 mm and the governing drift to 1/654. Over 60 years with three occupations, building once and relocating twice requires about one-third of the structural embodied carbon (195 against 570 kgCO₂e/m²) and about 55% of the structural cost of the RC practice. Design guidelines covering standardisation, the RC dock interface, connection detailing, tolerances, transport and inspection before reuse are formulated for the engineers and authorities involved in the development of the Haramain central areas.