Best way to scale a floor plan with grid and ruler?

[gaftalik]

Hello everyone,

I am using Xara designer pro X11, i know Xara is not designed for such a purpose but i am trying to sketch draw a floor plan and scale it to 30.1m x 17.2m, i've tried to modify the grid and ruler major spacing to 1 cm with 10 number of subdivisions and then drew my plan considering every 1mm as a meter but the final draw was up to 1% of an A4, then i considered every 0.5 cm a meter and enlarged my plan, then added guide layers to every major spacing but the larger i was zooming the more distant i was finding the layers from the accurate spacing number and then adjusted them manually, but couldnt even guess where to place accurately the 10cm and the 20cm remaining of each axis.(30.1m x 17.2m)

Layering, snaping to object and numbering manually take a lot of work and time, any better ideas to draw such a floor plan ?
How to insert the guide layers accurately on every major spacing or subdivision?

Thank you for your support.