80 Charlotte Street

Mixed-use, all-electric, scheme striving for reduced embodied and operational carbon.
Climate Change Mitigation Resource Use Advancing Net Zero Circular Economy Case Studies

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Project Overview

A nine storey mixed-use scheme comprising 321,000 sq ft of offices, 45,000 sq ft of apartments (including 10,000 sq ft of affordable housing), 14,000 sq ft of retail and a new public park.

Derwent London’s first purchased offsets related to the residual embodied carbon from the development, with its baseline embodied carbon footprint having been reduced by over 30% at practical completion in June 2020. The residual embodied carbon totalled 19,790 tCO₂e, measured from cradle to completed construction, or A1–A5 under the BS EN 15978:2011 assessment framework, which represents an intensity of 506 kg/CO₂e per m2. To offset the carbon for the scheme Derwent London purchased nature-based removal offsets from a community reforestation project based in East Africa.

Embodied carbon reductions were achieved through a range of measures including:

  • Retaining and re-using 30% of the existing buildings, including elements of the structural frames and the brick facades (1b)*.
  • Rationalisation of the new structure to reduce the amount of reinforcement and concrete required. The 500-600mm leaner floorplate meant another floor could be added.
  • Use of pre-cast elements including the façade which led to less waste and construction impacts and enables the building to be adaptable to possible future uses (2c, 3 & 5c)*.
  • Use of regional materials with high recycled content including: concrete with a 40% fly ash replacement, steel, timber& derivatives, and reinforcement is reported (5b)*.
  • Using materials with a low embodied carbon for finishes; gypsum plasterboard, paint, ceramic tiles; low embodied carbon blockwork (5a)*.

In relation to its operational carbon 80 Charlotte Street incorporated the following:

  • Derwent London’s first all-electric building, with central heating and cooling provided from air source heat pumps.
  • The building is supplied by electricity purchased from renewable sources and 80m2 of solar thermal panels on the roof to heat domestic hot water.
  • Optimised façade design, allowing a good balance between daylight entering the space, whilst limiting solar gain.

High-efficiency building services and fittings including an all LED system for main landlord areas and daylight sensors that enable light fittings to be automatically dimmed.

Location

Fitzrovia, London, W1

UK availability

Yes

Date added

Feb, 2022

Project partners

Derwent (Client); Make (Architects); Multiplex Construction Europe Limited (Contractor); ARUP (engineering)

Project status

In use. Completed 2020

Links

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Case Studies submitted by

Arup
Derwent London
Multiplex Construction Europe

Key Sustainability Objectives/ Outcomes

  • The building has now achieved BREEAM Excellent at Post-Construction, and EPC B. LEED certification is currently pending (targeting Gold).
  • Advancing progress towards Derwent London’s net zero carbon goals, both by achieving net zero carbon in construction, and providing an all-electric building that will continue to benefit from grid decarbonisation; as well as providing a reference point for future projects.
  • 80 Charlotte Street is Derwent London’s first all-electric building, with central heating and cooling provided from air source heat pumps, significantly reducing carbon emissions compared to traditional gas boilers. The Group is now targeting all-electric heating and cooling systems for all new development projects, as part of its net zero carbon ambition. 80 Charlotte Street will be used as a reference point for designing low carbon heating and cooling in future projects.
  • Elements being pre-fabricated off-site lead to reducing labour on-site and an industry leading safety rate (3)*.

Notable Approaches And Solutions

  • Retaining and re-using a significant proportion of the existing buildings, including the majority of the structural frames and the facades.
  • Arup carried out a detailed embodied carbon study early on, which has been tracked throughout the project.
  • In-use electricity data will be analysed and compared against TM54 modelling calculations completed by Arup at the design stage. As Arup will be one of the main occupiers, Derwent London has a unique opportunity to work with them to optimise operational energy performance.
  • 80 Charlotte Street is an all-electric building, with central heating and cooling provided from air source heat pumps, significantly reducing carbon emissions compared to traditional gas boilers.

Lessons Learnt

Early engagement between the client, architect, consultant team, principal contractor and sub-contractor was critical to ensuring that the stretching sustainability goals could be achieved. This early engagement then allowed for an ongoing open collaboration between all parties throughout the build to ensure any challenges could be solved early in the process.

 

* This project is included in the “How circular principles impact Carbon and Value” report.

Related members

Arup

Derwent London

Multiplex Construction Europe

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