Measured surveys involve taking measurements of sites or buildings to produce accurate data that is then represented as a drawing or model at a reduced scale. They are usually specified to an agreed level of detail, to acceptable accuracy tolerances, scale, delivery times and costs.
An initial collection of accurate site data will provide the 'building block' of core information on which all subsequent phases of planning, design and development are based. The drawings presented a range from traditional 2D hard-copy line drawings, topographical plans, floor plans, sections and elevations to 3D spatial information with feature intelligence that is shared between users throughout the building’s lifetime (design, in operation to demolition) through the building information modelling (BIM) process.
The systematic measurement processes involved in measured surveys will include the use of sophisticated survey equipment, but that situation may not necessarily infer accuracy. Irrespective of the methods of data capture, once dimensional data is published, there is some risk that it will be regarded by all potential data users as being complete and accurate and entirely ‘fit-for-purpose’.