ABSTRACT
Fulfilment of the need for satisfactory environmental conditions within a building, whether these be required for human comfort, material storage or in support of some process, is a task which has faced mankind throughout history. With the passage of time, a variety of forms of protection against the elements has been provided by structures suited to individual circumstances, the techniques being related to the severity of the local climatic conditions, to the materials which were available and to the skills of the builders. In this sense, the characteristics of those structures provided a form of inherent yet coarse control over the internal environment: finer control had to wait upon the progressive development, over the last two centuries, of systems able to moderate the impact of the external climate still further.
