Cargo, 25 North Colonnade; Cargo, 25 North Colonnade;

Cargo, 25 North Colonnade, London

Transforming a 1990s office tower into a dynamic mixed-use destination

The refurbishment and repositioning of this 15-storey building – one of the first to be built in Canary Wharf – creates a new mix of office and community space for occupiers, tourists and local residents. Along with 31,600m2 of flexible workspace, Cargo adds 1,850m2 of publicly accessible Market Hall and events space, reflecting how Canary Wharf is evolving to meet the needs of a rapidly changing demographic.

Revantage, a Blackstone company, engaged Arup as a trusted advisor for the project, even before acquiring the lease. Working collaboratively with the client from 2014, we engineered a cost effective and highly commercially viable scheme that returned the building to market quickly. 

How do you meet the needs of modern occupiers in older buildings?

Constructed in the early 1990s, 25 North Colonnade had been let to a single occupier since completion. Together with Revantage and architect Gensler, we brought the building up to the latest performance standards, with appeal for diverse occupiers. This extended the lifespan of the structure for decades to come.

Connectivity was a key driver, with the building less than one minute’s walk to the new Crossrail Place station. We engineered interventions to dramatically open up and expand the ground floor and dock levels, transforming the arrival experience. This included remodelling entrances to the north and south, and creating the new Market Hall, which supports multiple uses, from co-working to events. Set across two levels, this publicly accessible space draws footfall from the station and offers seating for up to 200 diners.

On top of the building, we introduced a new communal skyline roof garden for occupiers to enjoy, along with some private terraces on upper levels. We also upgraded offices to BCO specifications, reclad the lower levels and significantly improved cycle storage and changing facilities. Additional modifications to the core included installing extra lift shafts and extending lifts to the roof garden, as well as renewing equipment to speed up journey time, all enhancing the occupier experience.

How can engineers help clients overcome challenges?

25 North Colonnade is founded on marine piles and entirely constructed over the dock water. If you were to cut a hole in the lower ground slab, you would see the River Thames below. Our structural engineers completed analyses to verify that all extensions and interventions could be carried out without the need for expensive and complex foundation strengthening. Drawing on our extensive knowledge of Canary Wharf, we designed within local constraints.

Halfway through construction, following interest from BP – who went on to occupy eight floors – we engineered a series of changes to fulfil their needs. This ranged from adding a communication stair throughout their area and modifying the stair pressurisation system, to redesigning the base build plant for greater resilience. We led a resilience upgrade study that enabled the expansion of rooftop plant space to house the extra generators required. With the design and site team collaborating virtually at the height of the pandemic, these complex works were successfully completed in time for occupier handover. 

How do you upgrade energy performance in an existing building?

Working closely with Gensler, our engineers took a 30-year old building with an energy performance certificate (EPC) rating of E and turned it into a high C rating, with all Cat A office space achieving EPC B . This exceeds upcoming Minimum Energy Efficiency Standards. 

First, we upgraded the façade, developing a new fin concept that minimises solar gain, improving energy performance and occupier comfort. The fins integrate with the existing unitised curtain wall system and new façade elements, providing a low cost way to revitalise the building and improve efficiency. Together with the project team, we retained almost all the original façade, substantially saving embodied carbon and costs. 

We also renewed mechanical and electrical plant and systems, introduced heat recovery systems and updated the Building Management System, empowering facility teams to run the building for both occupier wellbeing and energy efficiency. Based on IES energy modelling, the building will save 1,460 tonnes of CO2 per year. This is a 50% saving on the previous building and means Cargo will be 35% more energy efficient than an average UK office. 

Signalling the future of Canary Wharf, Cargo is a unique milestone for the estate ” Ed Hodgson managing director, Revantage Europe

How do you achieve BREEAM Very Good in an existing building? 

Reusing the entire substructure and superstructure saved 52,000 tonnes of CO2 versus a new-build. We retained MEP plant and systems wherever possible too, validating their suitability through surveys and balancing cost versus risk. Keeping key elements such as rising ductwork saved installation time, cost and carbon. We also refurbished sprinklers, wet riser tanks and rooftop air handling units, extending their service life.

Alongside excellent local transport connections, the building offers 255 bicycle spaces, 333 lockers and 29 showers to encourage green travel and active lifestyles. The skyline roof garden and extensive planting promote biodiversity and increase opportunities for people to enjoy nature. The unobstructed island site provides exceptional natural light for occupier wellbeing.

The project achieved a BREEAM Very Good rating for sustainability and Wired Platinum score for connectivity, meaning it is futureproofed for technology.

Learn more about our Building retrofit expertise.