In terms of a lower environmental impact for a building project, which is better - to demolish and build a new one or refurbish an existing structure? Building projects are often faced with this question and for a recent Australian CBD Office project, Life Cycle Assessment (LCA) was used at concept stage to provide the answer in terms of environmental impacts for the local government planning authority. The verdict: life cycle analysis showed that refurbishing an existing building and retaining the structure has a much lower environmental impact over a 15 year span than demolishing and constructing a new building.