Assessment procedures, schemes and initiatives will be discussed which result in buildings which perform well in practice, and perform as modelled. The concept of design, and modelling for performance is explored along with schemes and processes which do or do not include these features. The characteristics of schemes which have been effective in this way are identified along with a relevant technical aspect - modelling - and a procedural aspect - the nature of the performance prediction or guarantee. Examples of projects are used to illustrate features, and current developments described along with suggestions for further development.