Evidence continues to emerge that green buildings achieve higher financial performance than conventional buildings (referred to as the green premium in literature). This green premium has been promoted as a potential driver of development of new green buildings as well as the green transformation of the existing office property stock. While the validity of this claim is still a subject of an ongoing debate, the office property market is highly susceptible to a range of local factors which could overshadow or undermine the power of such a premium in this regard. Adopting a case study approach, this study examines the local market forces influencing the office stock greening process in three British cities. Data was obtained through semi-structured one-to-one interviews and analysis of relevant documentary evidence. A total of twenty-five commercial real estate professionals were interviewed across the three cities, namely London, Manchester and Edinburgh. The results of the analysis show that office stock greening process differs among the cities and each market is influenced by distinct local factors. Findings suggest that while green premium may have the prospect of driving the green transformation of city offices, its impact is still largely muddled by the prevailing local market factors.