Case Study - CISL Entopia Building
Project summary
The former 1930s Telephone Exchange at 1 Regent Street, Cambridge, has been transformed into an ultra-low carbon sustainability hub and new home for Cambridge Institute for Sustainability Leadership (CISL). The building will house CISL’s Cambridge-based staff, currently spread across five buildings, and provide a dynamic virtual hub for its offices in Brussels and Cape Town, partner organisations in China, Australia and the UAE, its global corporate partners, alumni, fellows, associates, researchers and visiting academics.
Reuse summary
CISL develops leadership solutions for a sustainable economy, so it needed to lead by example when commissioning its new office base. The project incorporates the original structure, with a number of material reuse elements including the steel for the PV canopy, raised access flooring, carpet tiles and the oak reception desk. LED lights were reused from another building refurbishment, going through a full testing and re-warrantying process. Excess material and furniture was diverted from landfill.
Key facts/highlights
- 21,000kg CO₂e saved through reclaimed materials
- Reused steel frame for the photovoltaic canopy
- 350 LED reused light fittings with new warranties
- Repurposed front desk from refurbished Netflix office
- Reuse of raised floor
- Excess furniture and materials was diverted from landfill or donated to local communities, avoiding 85,747kg of CO₂e.
- 48% bio-based materials incorporated by volume
- Use of paint with 35% recycled content
- Project has achieved EnerPHIT standard
- Aiming for BREEAM outstanding and WELL gold
- 409 kg CO₂e/m² whole life embodied carbon of refurbished building (stage 5 construction stage assessment)
Project information
Project name | Entopia Building |
Location | Cambridge, UK |
Project type | Deep retrofit |
Sector | Provision of space for offices, start-up incubator and collaborative activities. |
Gross internal area (post refurbishment) | 2983 m² |
Project stage | Completed |
Cost per sqm | £4250 |
Total project cost | £12.69 million |
| Client | CISL (Cambridge Institute for Sustainability Leadership) |
| Architects | Architype (concept architect), Feilden + Mawson (executive architect) |
| Contractor | ISG |
| Engineers and consultants | Max Fordham (M&E engineering) BDP (M&E engineer, structural engineer and BREEAM/WELL consultant) Cambridge Architectural Research (structural engineer) |
Reuse highlights
Material/product | Steel for PV canopy |
Replacement | Reused steel |
Donor project | Pinewood Studios, was used to run cameras on a film set |
Supplier | |
Amount | 3.79 tonnes |
Carbon saving | At least 2,000 kg CO₂e |
Key considerations | Harleston Engineering were happy to use the reused steel as long as they had the correct paperwork and it had the original CE markings. |
| Material/product | Raised floor |
| Replacement | Use of existing raised floor from the building. |
| Carbon saving | 32 kg CO₂e/m² (85,0000 kgCO₂e total) |
Material/product | Lights |
Replacement | Refurbished LED lights |
Donor project | Cat A strip out from St James Place, London |
Supplier | ISG, partnered with Collecteco |
Amount | 350 fittings |
Key considerations | The warranty would no longer be valid but the manufacturer, a specialist in lighting design agreed to honour the existing warranty, after an inspection at its factory in Essex. The lights went from sitting within a ceiling system to sitting proud under the soffit. This also gave the chance to add uplighters, take off the end brackets and add wires to hang the luminaires. |
Webinar recording: CISL Entopia Building - Material Learnings and Reuse
- Discover material reuse stories from the landmark Entopia Building.
- Hear about the successes and lessons learned from the project team.
- Find out more about the use of bio-based and low carbon building materials, how conservation area constraints were overcome to achieve the required sustainability standards, an innovative PV array made from reused steel, plus reuse and refurbishment of LED lighting.
Links/resources
- https://www.cisl.cam.ac.uk/about/entopia-building
- https://www.cisl.cam.ac.uk/sites/www.cisl.cam.ac.uk/files/building_entopia_case_study_280922.pdf
- https://www.maxfordham.com/projects/the-entopia-building
- https://www.isgltd.com/en/news/entopia-building
- https://www.building.co.uk/buildings/a-deep-green-retrofit-crafts-a-sustainability-hq/5116123.article
- https://www.ribaj.com/intelligence/sustainable-retrofit-cambridge-institute-for-sustainability-leadership-riba-plan-of-work#
ASBP's Reuse Now Campaign
This case study is part of ASBP’s Reuse Now Campaign. The campaign builds upon the ASBP-led DISRUPT project, which is exploring the innovative reuse of structural steel in construction through the creation and adoption of new circular business models. Project partners and supporters include reuse stalwarts Cleveland Steel & Tubes, global construction specialist ISG, National Federation of Demolition Contractors, and Grosvenor, the world’s largest privately-owned international property business.
ASBP has been working on the topic of material reuse for nearly 10 years, with past activities including the Re-Fab House feasibility study, research with University of Cambridge identifying the barriers to structural steel reuse, and more recently, a sold-out Reuse Summit.
This previous experience is further enhanced with in-house expertise from Technical Director Dr. Katherine Adams and Research Associate Dr. Asselya Katenbayeva, who bring 25+ years of academic and industry-focussed research and development on the topics of waste, reuse and circular economy.