Originally built in the 1970s, 90 Long Acre is a 260,000 sq ft landmark in Covent Garden, London. Northwood Investors wanted to repurpose the iconic but obsolete Brutalist building, designed by noted architect Richard Siefert, to revitalise existing office areas and floor space, upgrade its performance and provide new public space and retail opportunities at ground level.
Working closely with the architect Gensler, Arup provided a series of interventions to retain as much of the existing structure as possible while reducing operational energy use in the building by over 70%, enabling it to outperform new-build energy standards. We targeted WELL Platinum certification and Fitwel 3 Star – the highest levels on the leading international frameworks for health and wellbeing in buildings.
With substantial whole life carbon savings, wellbeing interventions, natural ventilation, biodiverse terraces, public spaces and green travel features, The Acre has achieved a SCORS: A+ and Fitwel 3 star rating, and is on track to achieve BREEAM Outstanding, 4.5 NABERS UK Star, and WELL Core Platinum.
Transforming energy performance in a 1970s building
Energy efficiency interventions have reduced operational energy use, from fully renewable sources, by over 70%, whilst the building’s blue roofs will harvest rainwater, giving the building a 50% reduction in water use compared to typical building regulations.
‘Infill’ extensions make the building’s thermal envelope more effective, reducing heating and cooling loads. Other passive improvements include internal insulation fitted to existing façades and high-performance new façades. A new, all-electric heating and cooling system uses high-efficiency pumps that reclaim heat for hot water. Artus fan coil units will condition Cat A space during extreme temperatures, taking up less office space and using 50% less power than traditional units. A smart platform allows real-time energy analysis and predictive maintenance of the plant, along with live monitoring of window operations.