DEFRA Engineering Delivery Framework

Weybridge, Surrey

Walter Lilly are currently appointed as a contractor on the Engineering Delivery Framework with the Department of Environment, Food and Rural Affairs (DEFRA) for refurbishments on its APHA Weybridge site. Walter Lilly has successfully secured a position on two Lots.

In Lot 1,  Walter Lilly is one of three contractors selected to work on designing, building and installing works inside a containment environment, and also testing, commissioning and validating newly installed equipment in a CL3 or CL4 environment.

Walter Lilly is also one of three contractors chosen for Lot 2, in which works include designing, building and installing general accommodation and site infrastructure projects which do not require working in high containment environments.

DEFRA’s Weybridge site is a world-class scientific facility with more than 20 high containment laboratories over a main site of 100 acres.  As a wide variety of pathogens are contained on site, Walter Lilly’s experience and expertise in dealing with designing, building and installing works within a containment environment was crucial in being selected for the framework agreement.

Since the Engineering Delivery Framework commenced in 2017, projects have included:

  • Electron Microscopes Relocation: Internal refurbishment works to relocate two electron microscopes, and the conversion of a room to house them. Works included the installation of suspended ceilings, new internal doors, anti-static flooring, black-out curtains and new laboratory furniture – all required in order to maximise the performance of the electron microscopes.  A plant room extension to house the associated services equipment was also built.
  • BMS Upgrade: A pilot upgrade to Building B265C’s control systems, replacing the old installation of building control systems equipment which had reached its end of life. The aim was to retain as much of the old installation as possible, reusing the field devices such as motor drives, sensors and actuators where possible, whilst removing the outdated BMS controllers from their housings and fitting new controllers in their place.  Upon successful completion of the pilot upgrade, Walter Lilly was reappointed to provide the design, supply and installation of new BMS controllers for the HVAC plant in B265 Suites A and B and remaining plant, and replacement of the fumigation dampers including appropriate actuators in Suite A.
  • B90 Demolition: Demolishing the B90 building in preparation for the upcoming APHA incinerator upgrade.The work was complicated by the presence of asbestos in the existing B90 building which had to be removed by a licensed contractor prior to the actual demolition taking place.  As the building was surrounded on three sides by other buildings that remained in use, considerable care had to be taken to avoid disrupting the day to day operation of the site’s surrounding area.
  • Service Yards: Construction of two temporary service yards to prepare for the APHA incinerator upgrade.
  • Mycoplasma Laboratory: Relocation of the existing mycoplasma laboratory to a more suitable location due to dilapidation of the existing building. In order to relocate the lab, the new area had to be made compliant to hold Schedule 5 pathogens. Full refurbishment of the laboratory, including significant modifications to the walls, doors, windows and slab penetrations were carried out.  The adjacent working laboratory suites remained occupied throughout the works.
  • Cattle Handling Facilities: Walter Lilly has carried out several Design and Build projects at DEFRA APHA to upgrade and enhance a cattle housing facilities used to house cattle and other large animal species infected by TSE. Works carried out include refurbishment of the existing facilities to enhance the health and safety aspects for operatives, improve the animal welfare provisions including cattle handling devices, races and feed faces, replacement of floor finishes, upgrade the external space, and upgrade the existing M&E system. The works were Home Office, HSE and Animal Care guidelines compliant.
  • Ventilation Upgrade: Upgrade to the basement ventilation system of one of the site buildings with the capability to service the existing plantroom for a period of no less than 25 years. The upgrade ensured SAP04 and ACDP3 facilities within the building could continue operation.

Project credentials


Weybridge, Surrey




2021 DEFRA APHA Critical Works Award


Project Manager: Currie & Brown
Architect: Architon
PQS: Currie & Brown, Rider Levett Bucknall
Structural Engineer: ARUP, Ross and Partners
Services Engineer: ARUP, MG Partnership

“I’d like to nominate Walter Lilly for their Covid response and attitude to health and safety in general. They mobilised really well, have been commended on site for their Covid measures but their attitude to health and safety throughout the entire project work in B265 has been excellent. DEFRA APHA”
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