In order to obtain and record precise measurements in a scale drawing, calibrated equipment is needed. The most basic scale-drawing tool is a scale rule, which is specifically dimensioned to give precise measurements.
Different sorts of designers will use different sorts of scale rules. For example, an engineer and a product designer will use different scale systems as references in their design work and so will need to use different types of scale rule that work within these systems to record the measurements.
When surveying spaces, a tape measure is a basic, but essential, piece of equipment. Tape measures are available in a variety of sizes and again the most suitable size will depend on the scale of the object or space to be measured. For example, a three-metre tape measure is useful for small – dimensioned spaces and objects, but if measuring a building it will be useless and a 30-metre tape will suit this purpose far better. In addition to traditional tape measures, digital devices will accurately measure a room or building using laser beam technology.
To understand the different levels across a site, a theodolite is necessary. A theodolite is an instrument with a rolling telescope that is used for measuring both horizontal and vertical angles. It will be placed at a particular point on a site to create an ordnance datum for the site, from that point all levels can be described relative to that datum. A large site can have a considerable range of levels, and this can affect the subsequent design or scheme layout.
A building proposal can sometimes benefit from full-size exploration. Renaissance architects favoured this technique and often made full-size representations of elements of proposed buildings (such as their dome or cupola structure) to give an impression of a new building form. In cases of specialised construction, it may be that a component needs to be made at full size to ensure that it will fit its intended context. Or there may be a need for experimentation; a particular element of the architectural scheme may need to be tested as a full-size piece (in the same way that a prototype may be constructed in product design or engineering) to ensure that it works properly. There may also be innovative aspects of the design scheme that need to be built at full size in order to be properly understood.