Activities in the building industry in Europe concentrate increasingly on a combination of renovation and new-building. A prerequisite for comprehensive IT supported design and planning in the context of existing buildings is both the use of on-site computer- aided surveying techniques and the integration of all professional disciplines in an integrated information and communication system. The starting point is often the building survey on site. An examination of currently available IT tools and hardware shows insufficient support for planning within existing built contexts. Surveying equipment has been derived from other disciplines without being modified to cater for the specific needs of building surveying. This paper describes a concept for computer-aided digital building surveying equipment based upon a wearable computer and AR to close the gap between specialist equipment adapted for use in building surveying and the need for simple straightforward surveying equipment for architects and engineers.