This paper describes full-scale demonstration projects on recycling and the use of reclaimed materials in construction work at BRE. Included are both demolition and construction phases and, in particular, the first-ever use in the UK of recycled aggregates in ready-mixed concrete. Reclaimed bricks and reclaimed flooring materials were also used. The projects, a new office and seminar building at Watford and a 500m3 strong floor facility at Cardington near Bedford, also enabled the practicalities of reuse and recycling to be studied in terms of commercial, operational and contractual issues. At Watford, 96% of waste from the demolition of old buildings was recycled, including the resale of roofing sheets and timber boarding, and the salvage of other materials for internal use or donation to charities. Difficulties in the supply of suitable reclaimed and recycled materials for new construction highlighted the need for improved coordination and quality control. Overall, this increased costs, but savings were made in the demolition contract and in the use of reclaimed flooring. Future savings of costs may be made by pre-planning for the use of waste streams for input to the design process plus a sensible approach to risk management.