The process of converting a heritage building to contemporary use is a rare science and a fine art.  It is a rare science from the point of view that one is dealing with original building fabric which may be very old, fragile and unstable.  Naturally, intervention into such fabric by way of modification must be a carefully considered process and a well researched project.  The reason for this is that one only gets one go at it.  If the intervention is too heavy-handed, important fabric may be lost.  It is rather like restoring very old paintings by the masters.  One cannot simply slap on new paints onto a 400 or 500 year old canvas.  One has to research and experiment with pigments and chemicals to ensure that the original is not in any way diminished or damaged.  This is the rare science of heritage because it comprises well studied resolutions to the modification of heritage buildings and places.

There are several key documents that are used by conservationists in Australia today to ensure that fabric and places are approached with the right attitude and skills.  First amongst these is the Burra Charter which is a set of guidelines laid down to assist conservators in how they approach a heritage project especially where fabric is being altered or restored.  The charter is not a legislative document.  It is merely a set of principles – called articles that deal with fabric, the conservation process and the communication of heritage values (interpretation strategies) for visitors and users of heritage places.

The heritage process is also a fine art.  Apart from the fabric issues, there are wider issues of compatibility and adaptive re-use.  How does one extend a heritage building or add storeys to it?  What factors are involved in the setting and curtilage of buildings? At what point will a heritage project become too heavy-handed as a result of which intrinsic values will be lost or overwhelmed by new work?  These questions go to the heart of the matter. 

Modifying heritage buildings entails a number of factors:

1. Scale
2. Height
3. Morphology
4. Materiality
5. Proximity
6. Setting
7. Curtilage
8. Views and Vistas
9. Interior fabric
10. Layout
11. Introducing services