Thank you very much! Been racking my brains and unable to understand a single thing on the sketch until I came across this video. Made my day . Thanks plenty!
Most drawings will give you all measurement including where the window is from a corner measurements and calculations is a whole different subject. Every now and again a draftie might leave a small measurement out which is able to be worked out.
In the UK I've found a lot of internal stud walls (modern builds) are there or there abouts, floating between 9cm to 13cm I've found or more. Older properties or internal brick walls etc bigger for sure as standard but 9cm isn't unlikely if stud or similar.
