ISG awarded £50m low carbon office scheme in London

ISG has won a £50m project to redevelop and refurbish Woolworth House in the heart of London’s West End.

The mixed-use scheme, for General Projects with Henderson Park, will increase the building’s gross area by more than 40% to over 236,000 sq ft.

The project includes the complete refurbishment of the existing eight-storey office building, located at 242 Marylebone Road in the London Borough of Westminster.

Renamed Metropolis, the new building will benefit from both office and retail facilities, with external green roof terraces across every floor.

An events auditorium, rooftop-bar, on-site coffee shop, cyclist zone as well as new health and wellbeing amenities will also be added.

A new extension will significantly increase outdoor and green space, adding more than 6,000 sq ft of new landscaped gardens. 

To achieve this, the scope of work includes infilling the existing courtyard area up to the seventh floor, providing tiered planted terraces and the structure will be extended with various additions across floors three to eight.

In addition, the existing roof plant enclosures will be removed and consolidated, allowing the creation of rooftop office pavilions on level five and eight.

Designed by London architect AHMM, the environmental performance of the refurbished building will be boosted to a BREEAM rating of Outstanding. 

Careful retention of existing building material will result in more than 4,500 tonnes of carbon saved during the construction process and diverted from landfill. 

The use of engineered timber floors to all building extensions has dramatically reduced embodied carbon, equating to a 73% improvement against RIBA 2030 targets.

The masonry facades, concrete frame and cores will also be retained.

Jim Knowlton, ISG project director, said: “Originally constructed in the 1950s, Woolworth House is an exemplar of how a low carbon approach can transform our cities’ dated building stock. 

"Underpinned by environmental, social and governance (ESG) considerations, the scheme shows how adapting assets into smarter office and retail environments, with more green spaces for occupants, can future proof London’s commercial property market.

“Following the successful completion of 66 Shoe Lane in 2020, Woolworth House is our second collaboration with Henderson Park.

"The project builds upon the success, expertise and shared learnings of the same delivery team, now applied to this trailblazing low carbon scheme.”