How is scale drawings used by architechs?

No single scale is used in Architecture. The scale used depends on the level of detail required in the drawing.

In metric drawings commonly used scales and some of their likely uses are:

* 1:1000 for site plans

* 1:500 for site plans * 1:100 for plans and elevations

* 1:50 for plans, sections and elevations

* 1:20 for part plans, sections and internal elevations * 1:10 for details and joinery

* 1:5 for details