Material Works Architecture adapts London County Hall into workplace


Project data

The project retains and reuses as much of the existing finishes and fittings as possible with interventions added with full life-cycle considerations. These include demountable modular partition wall systems developed by U-build as part of an ongoing project with the client. The plywood design has minimal mechanical fittings and can be easily reconfigured. A large portion of the wall modules used were demounted and moved from Sustainable Workspace’s previous home on a lower floor.

Source:Fred Howarth

Existing doors, windows, flooring and plaster were also retained and new decoration limited to areas of high footfall and expected wear.

To achieve this we had to challenge our designer’s instincts and assumptions at every turn. For every action considered, we assessed the practical and aesthetic value against the financial and environmental costs – did we really need it? If so, how could we achieve it with the minimum environmental impact? What is it made of? Where did it come from? What will happen to it at the end of its current use?

Source:Fred Howarth

Architect’s view

During the design process, we used carbon calculation software to assess the impact of the design against a typical benchmark office fit-out. One of the most striking conclusions was realising the impact of reducing the scope and expectation of the finish. Omitting the usual layers of suspended ceilings, raised floors and plastered/painted surfaces creates a stark difference.  The suggestion is that to make a real impact in this sector, expectations of how retrofits look and feel need to change, moving away from ideas of reinvention towards a less polished celebration of what’s already there.
Dickon Hayward, director, Material Works Architecture

Where new interventions were proposed, every effort was made to construct adaptable and reuseable pieces from low-impact materials. Joinery items are modular with clearly visible fixings and limited adhesive that allow for easy disassembly and reinstallation elsewhere. Where possible, reclaimed materials were used alongside reclaimed fittings and furniture. Elsewhere, materials were chosen for their low embodied carbon and limited post-life impact, emphasising materials with high renewable, waste or recyclable content.

From the outset of Sustainable Ventures, we knew the workspaces we developed had the potential to have the biggest single impact on the environment while also giving an opportunity to demonstrate leadership in the net zero innovation community.

The retrofit is a test bed for innovative materials for client Sustainable Workspaces, adopting a low-impact design philosophy focused on minimising embodied energy

Our County Hall space is all about thoughtful design and careful restoration. Sitting within a century-old building, we limited our environmental impact by keeping new materials to a minimum. Where new materials were necessary, we sourced innovative alternatives from ecosystem members and sustainable suppliers without increasing the overall retrofit budget.
Andrew Wordsworth, founding partner, Sustainable Ventures 

Percentage of floor area with daylight factor >2% 70%
Percentage of floor area with daylight factor >5% 40%
On-site energy generation None
Annual mains water consumption 20 l/person/day, 5 m3/person/yr (estimated)
Airtightness at 50Pa Unknown
Heating and hot water load 19.13 KWh/m2/yr (calculated by DSM modelling)
Overall area-weighted U-value 2.5 W/m2K (excluding floor, existing building)
Design life 15-20 years
Embodied / whole-life carbon 48.05 kgCO2eq/m2 (excluding MEP)
Annual CO2 emissions 6.21 kgCO2eq/m2 (calculated by DSM modelling)


The brief from Sustainable Workspaces was to transform an abandoned space within a listed building into a vibrant and affordable workspace. The challenge lay in doing this with a real commitment to low-carbon intervention, a limited budget and within an existing space in a state of serious disrepair.

These include some joinery finishes created from waste coffee and vegetables, carpentry using composite boards formed from agricultural waste, cork flooring, mycelium acoustic baffles and a countertop formed from reclaimed building rubble. Further focus was given to biodegradable bonding agents and processes to ensure specified materials were easily recyclable at end of use.


Client’s view

One of the joys of the project was to work alongside some of the companies within the Sustainable Ventures ecosystem which are pioneering research into low-carbon materials. Biohm produced joinery finishes formed from bio-waste streams and acoustic baffles made of mycelium; U-build produced modular partition walls, a large portion of which were formed from modules previously installed in SW’s former space; Blast Studio supplied light fittings formed from recycled single-use paper coffee cups and new plaster was provided by Adaptavate, which has pioneered carbon-positive techniques for plaster manufacture.

Sustainable Workspaces is a branch of Sustainable Ventures, which works with sustainable start-ups to provide investment, community, innovation and workspace. Having outgrown its previous location, it acquired 3,600m2 within part of the fifth floor of  Grade II*-listed County Hall – the former home of the Greater London Council – a space that had been untouched since the GLC was abolished in the 1980s.

The design has much less embodied carbon than with a typical fit-out, saving 1,150 tonnes of carbon.

Further elements were constructed using materials sourced from waste streams, natural plant forms and unwanted industrial byproducts, while items of furniture and fittings were sourced from reclaimed supplies.

Start on site October 2022
Completion date April 2023
Gross internal floor area 3,686m2
Gross (internal + external) floor area Not applicable
Form of contract  Design and Build – JCT DB16
Construction cost £4.25 million
Construction cost per m2 £1,153
Architect Material Works Architecture
Client Sustainable Workspaces C.I.C.
M&E consultant Taylor Project Services
Project manager and QS Quartz Project Services
Modular wall design U-Build
Services engineer Taylor Project Services
Mycelium and waste stream finishes Biohm
Principal designer Material Works Architecture
Principal contractor Cast Interiors
Approved building inspector JM Partnership
Main contractor Cast Interiors

Environmental performance data

Material Works was commissioned to work up designs with a series of interventions to articulate the space into a workspace: the creation of private offices, event spaces, innovation labs, cafés and break-out areas, all with a backdrop of the existing historic finishes.

Repair and alterations to the existing building were minimised. All doors, windows and finishes that could be retained were. Fabric repairs were limited to those essential for functional requirements and new decoration limited to areas of high wear and traffic. The layers of previous finishes are all on show, as are the scars left from previous alterations and fit-outs.