Dudleys Consulting Engineers has completed the complex remediation of a 12-acre former gas works site near York city centre, paving the way for the development of up to 600 new homes.

The award-winning firm was appointed as the principal engineering partner for ‘The Gas Works’ development, overseeing all ground engineering operations. The brownfield site at Heworth Green was previously occupied by a range of industrial structures including 22-metre-high gasometers, warehouses, office buildings, extensive gas infrastructure, an electricity substation, and a telecoms mast.

Dudleys joined the project in 2018, contributing expert evidence and technical advice during the planning stages. In 2020, the scheme received planning permission for full site demolition, remediation, and a residential-led development.

In collaboration with Dunelm Geotechnical & Environmental Ltd, Dudleys carried out extensive site investigations to assess contamination levels and coordinated with the local authority to develop a safe remediation strategy. A key component included the removal of a major over-ground gas main serving York city centre, which was successfully diverted underground.


The company partnered with remediation specialist The Sirius Group to deliver a thorough programme of works. This included full site turnover, excavation and treatment of contaminated soils, reengineering and crushing of demolished materials, protection of critical gas infrastructure, civil engineering works, and multiple service diversions.

Andy Walker of Dudleys Consulting Engineers commented: "We have been advising on The Gas Works in York for over six years with a very carefully procured strategy to clean up the site ready for new development. We faced many challenges due to significant contamination from 100 years of coke and sea gas uses with many buried structures. Our expert team has successfully navigated these challenges, and we are delighted to hand over this strategically important, disused brownfield site ready for much needed new residential accommodation in York.

"The scheme has been a great ‘Team Effort’ drawing on the experience and capabilities of many consultants and individuals including Aspect4 Ltd (Project Management), O’Neill Associates (Planning Consultants), Vincent & Partners (Architecture), Dunelm Geotechnical (Site Investigation/Remediation), and Ellmes (Development Director)."

Dudleys has a strong track record in delivering engineering solutions for contaminated and historically complex sites. Previous projects include Greenside Mills near Huddersfield, Blossom Fields in Temple Newsam, and AAA Park in Mirfield.

Currently, the consultancy continues to provide strategic advice for the redevelopment of Sunnybank Mills in Leeds and Globe Mills in Slaithwaite, and supports the Keighley and Worth Valley Railway Preservation Society with its heritage properties.