The milestone marks significant progress on the development for client Klarent Hospitality and principal contractor Edgewater which will add 96 guest rooms - increasing the iconic hotel’s overall capacity by 30% - alongside upgraded servicing and back-of-house infrastructure.

Situated over the historic footprint of the former Princes Street Railway Station, the heavily constrained site presented complex sub-surface and structural engineering challenges. The Will Rudd team designed and executed complex substructure solutions directly adjacent to shallow historic foundations and legacy structures, including four-foot-thick brick retaining walls and arched roof basements.

To protect critical infrastructure without adding additional weight to an underlying historic brick public sewer, Will Rudd specified an advanced substructure solution featuring 160 cased Continuous Flight Auger (CFA) piles, integrated ground beams and a single-storey reinforced concrete shear core.

Above ground, the structure transitions from a heavy steel transfer grillage at the entresol level to a load-bearing light gauge steel frame (LGSF) wall system extending to the roof. Through double-span beam designs at the entresol level, Will Rudd reduced structural zone depths and steel material usage, driving down embodied carbon and construction costs while maximising interior spatial efficiency.

Part of the Curio Collection from Hilton, The Caledonian Hotel project forms part of a robust trio of high-profile city-centre hotel and hospitality projects currently being delivered by Will Rudd across Edinburgh, showcasing the firm’s expertise in navigating constrained gap sites, heritage assets and complex adaptive reuse.

Elsewhere in Edinburgh, between Princes Street and Rose Street, Will Rudd is providing both permanent and temporary works design services for RIGH Properties on a new 60-bedroom luxury apart-hotel. The ambitious development involves the partial demolition and re-framing of three under-utilised city-centre buildings fronting onto Princes Street.

Following complete internal strip-out within the Category B listed 71 Princes Street, groundworks are now underway, preparing for new integral steel framing to be threaded through existing structures.  To the rear of the site demolitions are advancing to the former dairy building on Rose Street Lane, with contiguous piled basement formation continuing on the Rose Street frontage.

Simultaneously, Will Rudd is delivering structural engineering services for a 24-bed extension to RIGH Residences at 71 George Street. The project involves the complex refurbishment and extension of an adjoining 1980s office building, converting under-utilised commercial space into high-end hospitality accommodations.

Commenting on the city’s expanding hospitality landscape, Stuart Fleming, director at Will Rudd Edinburgh, said: “Edinburgh’s hotel sector has consistently proven to be one of the UK’s most resilient and dynamic markets. As demand for quality accommodation grows, unlocking potential in the city centre increasingly relies on smart engineering that can navigate complex, heavily constrained gap sites and adapt historic building stock.

“Reaching the topping out stage at The Caledonian Hotel is a testament to the collaborative effort of the entire project team. From navigating legacy railway foundations and active utility networks at Princes Street to threading modern steel frameworks through heritage buildings on Rose Street and George Street, our focus remains on lean, precise engineering that safeguards Edinburgh’s built heritage while delivering commercial value for our clients.”

The Caledonian Hotel extension project is being delivered alongside project manager Fitzsimons, main contractor Edgewater Contracts, Axiom Architects, MEP engineers PSH Consulting, principal designer Green Build, and interior designers Cunningham McLean.