The first 2009 issue of Delta t covers the latest industry news - including the retirement of Stephen Loyd, BSRIA's Chief Librarian. In this issue, Stephen gives his final answers to members' engineering questions. Also included are technical news and a training update. The thoughts of BSRIA delegates towards measures needed to achieve Zero Carbon were drawn out at the 2008 BSRIA Briefing and are reported here. A comparison of the strengths and weaknessess of both the Building Research Establishment Environmental Assessment Method (BREEAM) and the Leadership in Energy and Environmental Design (LEED) is also given in the environmental update. The future for sales of air-conditioning systems is also discussed by examining recent market trends.