Measured survey & measured drawing

On drawing.

The observation and concentration required to understand an object, depict it and see how its form fits in with the pattern of known forms is the soul of recording architecture, it is the very essence of a process which, when buttressed by sound measurement will produce the clarity needed for successful measured drawing.

Often, particularly since the invention of the camera, the value of drawing has been seen as unscientific, selective or unobjective.

This may be true but it is drawing, with it’s necessary constraints of line and form that provides the definition of detail needed to document beyond the surfaces of a building and reveal the key elements that connect, link and bind structure into a whole, not only spatially, but into an historic context.

A lost art?

To examine drawing need there are three questions to consider:

  • Measurement: what are appropriate methods according to cost/ time /project scope?
  • Selection: what is the purpose of the data, what do we record ?
  • Communication; what is the data form required and how is it to be transmitted?
SLAM data falls well short of the mark.
A site sketch makes it clear
Combining SLAM with measured drawing defines the form.

An holistic approach to metric documentation is sound practice, to rely on a single method of data acquisition and assume it will meet all information needs is to risk the capture of redundant information. It is very rare for a survey to be commissioned without a purpose and promoting data for the sake of it is damaging to the relationship between the surveyor and the client.

The skill-set to identify diagnostic details, sketch them and incorporate them into a measurement set is not rocket science but the geomatics sector seems to be focussed on technologies, not observation, feature extraction or the wider contexts that define form. The skills of data interpretation or differentiation are thematically dependent, integrating that skill into metric processes should be a priority when commissioning survey; in the past when capture technologies were less ubiquitous this was so.

A shift to presenting undifferentiated data as information has happened. As capture tools become more accessible the outputs become less defined by use than by acquisition technology. Many survey practices offer ‘measured building survey’ or ‘scan to BIM’ but very few show any evidence of architectural draughtsmanship. In the SUA world it is almost impossible to find operators who can take outputs from Pix 4D into a site drawing despite claims to be ‘surveyors’.

Seems like everyone with a drone is a surveyor now.
getting a site plan from drone capture is a matter of basic cartography.

When did we stop expecting surveyors to be able to draw a map? Was it when surveyors told us the the point cloud is the deliverable?

Archaeologists, building historians, conservators, planning officers and investigators all have strong traditions of drawing and know what they expect to see on a drawing. It should be a simple matter of specification to ensure the desired drawing quality.

I do not believe measured drawing is ‘a lost art,’ far from it, drawing standards at HABS/HAER for example show current skill levels in the US are being applied to a range of capture technologies with quality results. If good examples are promoted by our leading heritage institutions good practice will follow.

Historic England are preparing a 3rd edition of Measured & Drawn techniques and practice in the measured survey of historic buildings: Guidance for good practice. Which should see publication in the new year.

Seasons greetings,

B

About billboyheritagesurvey

Heritage worker
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