Places for London, Helical and McLaren mark development milestone at 10 King William Street

The shape of a new City of London landmark office developed by Places for London and Helical plc, 10 King William Street, has become clearly visible as all the parties celebrated on-time completion of the structure on 12 January.

Joint venture developers Places for London, Transport for London’s property company, and Helical plc were joined by funders HSBC and McLaren Construction in putting the final bolt in the steel structure as part of a traditional “topping out” event.

The partners and their guests enjoyed the views of St Paul’s Cathedral that will be available to users of the outdoor terraces on the building’s three upper floors.

The eight-storey office development with basement and mezzanine wraps around and over the new Cannon Street entrance to Bank station, one of London’s busiest underground stations. It will deliver 139,000 sq ft of office space, with 7,260 sq ft of terracing, 1,950 sq ft of ancillary retail and extensive occupier amenity provision, including a comprehensive wellness suite. The building is targeting BREEAM Outstanding, NABERS 5* and WELL Platinum certifications.

The new entrance to Bank station which opened in February 2023 was key in unlocking land to make the development possible, as well as making it easier for thousands to move through the station more easily.

The steel structure includes beams of up to 20m long, radiating out from a concrete core and allowing largely open and column-free office floors of up to 22,423 sq ft.

Construction work started in June 2024 and is due to complete by December this year. The new façade will include precast panels with windows and aluminium cladding preinstalled. The stone and brick façade of the previous building on Abchurch Lane will be reinstated on the new structure after having been removed brick by brick and restored.

One of the main challenges for the project is working above a live Underground station. The station’s concrete shell was designed to support the steel columns of an over-station development, but the construction team must still follow detailed procedures to avoid disruption to transport services from vibrations. The steel structure sits on a 1.8 metre thick raft foundation that avoids the need for piling around the station’s tunnels.

Built into the construction project are many opportunities to train and upskill Londoners. Apprenticeships have been provided via local colleges and universities alongside work placements including internships, work experience and for those studying T-Levels. Vacancies and work placements were advertised through the job brokerages of the City of London and surrounding boroughs.

Matthew Bonning-Snook, Chief Executive of Helical, said: “Our topping out ceremony marked a key milestone in the delivery of 10 King William Street, a highly sustainable and amenitised office building in the heart of the City that is attracting interest from a number of potential occupiers. This is the first project in our joint venture with Places for London and we are excited to bring forward this best in class asset before the end of this year.”

Graeme Craig, Director and Chief Executive at Places for London, said: “This is a fantastic milestone to reach at our first development through the Platinum Portfolio joint venture between Places for London and Helical. Here, at 10 King William Street, and working together with McLaren, we are bringing about new, valuable and sustainable office space in the heart of the City of London –building and realising a vision for the future.

“This topping out ceremony celebrates the incredible partnership we’ve built with Helical and partners across the industry to deliver not just 10 King William Street, but also our wider Platinum portfolio, with exciting progress expected this year at our sites at Southwark, Paddington and Farringdon, and even more to follow.”

Darren Gill, managing director for London & South at McLaren Construction, said: “Despite the familiar technical challenges of working above one of London’s busiest and most complicated Underground stations, this impressive building is taking shape on schedule. In the process we’ve been able to improve on an already sustainable design by reusing some existing materials and substituting some high quality, low carbon alternatives.

“Keeping to programme is down to some rigorous management systems and toa confident and expert team of up to 240 people on site daily. Those experienced people are providing a great grounding to those colleagues across the supply chain, including 12 apprentices, who are working in construction for the first time and will be using this prestigious project as a springboard for long careers.”

The joint venture’s project team includes Fletcher Priest Architects and structural engineers Robert Bird Group. In addition to main contractor McLaren, the construction team includes Keltbray, who installed the concrete core, basement and ground floor slab, Bourne for the steel frame, Dornan for MEP, Techrete for precast façade, GIG for the curtain wall, PAYE for the retained façade and Kone for lifts.

10 King William Street is one of three new over-station developments by the partnership of Helical plc and Places for London. The new commercial office developments at Bank and Paddington total around 400,000 sq ft while a purpose built student accommodation development at Southwark provides 429 studios and 44 affordable homes.