Suggests that developers will be under growing pressure both from government and occupiers to make refurbished office buildings more environmentally friendly. TheUK implementation of the Energy Performance of Buildings directive (Directive 2002/91/EC) from January 2006 will mean that over the following three years all refurbishments of over 10 000sq ft will be subject to higher energy efficiency levels and all buildings will have to undergo a certification process to judge energy efficiency. Discusses the market implications of energy efficiency ratings, the fears that a green premium might creep into rents as developers seek to offload extra costs and the findings of recent DTZ research that indicates that occupiers are unwilling to pay higher rents for buildings rated highly energy-efficient. Provides a summary of the legal issues and the British Council of Offices' advice on what developers can do to green up revamps.