Planning drawings accuracy?

[MissUGirl]

I have the floor plans for my building from the local authority planning department. There is a note on the bottom: (scale 1:100). Does that mean that if I take the measurements of the rooms from the piece of paper and multiply by 100 I will get the actual size of the rooms?

Apologies if this is an obvious question but I need to make sure.

Yes, assuming you use a ruler that is in cm. So 1cm on the plan equals 100cm in real life.

Yes! Drawn length x scale factor = actual length, I think!

Yes. It means 1cm on the drawing is 100cm (1m) in real life. You can buy a scale ruler that has different scales marked out on it. If you use the 1:100 scale side you can check the measurements of anything on the drawing.

Yes, definitely get an architects/technical ruler. It makes things so much easier.

Fabulous. Thanks everyone!

You can, but don't use it to order Windows or carpets or anything - it's not perfectly accurate.

There will be a note on the drawing that says something like 'do not scale - contact architect'

Obviously it's fine if you just want a rough idea of sizes.

Oh! I've just noticed there is a note on the bottom of the drawings:

"All dimensions must be checked on site and not scaled from drawings."

Does that change things at all?

Thanks @WeeDangerousSpike. I need a very accurate (if not exact) estimation of sizes. There is a service charge dispute going on with my building and the charges are apparently based on the floor size of each apartment.

Drawings always have the note about not scaling from them. All engineers and architects drawings will have this. You do need to be careful that the drawing is printed off at the correct size (and make sure not to print at scales to fit just at 100%) and even then if a drawing has been scanned In the scales may be slightly off. It is best to see if there are any dimensions noted. Then take the largest dimension noted on the drawing and use that to work out a scale. Engineers drawings are usually in mm not cm.

Out of curiosity, Is there a reason you can't just measure your building to get the dimensions rather than working off a drawing?

You need to make sure the drawings are to original scale ie. a0 size not copies which may have reduced or distorted them. If it is a new build they may have changed on site.

@babyboyHarrison 55 apartments and not all the leaseholders are cooperating, so I thought it would be easier to do it from the architecht's drawings.
No dimensions on the drawings, unfortunately.

@LIZS The paper seems to be slightly larger than A4 when at 100%.
Definitely not A0.

You may be best off contacting the architect on the drawings to see if they did the construction drawings. That or take some measurements on site to help you get a few known dimensions then use those to scale your drawings from. Planning drawings may not be accurate enough though. Things do change between planning and construction. Maybe ask the local authority if they provided building control. They won't be able to give you the drawings but they might be able to tell you the names of the engineers and architects and then you could contact them.

Thanks @babyboyHarrison. The architects' names are on the drawings so I can contact them directly. I didn't realise there would be a different set of drawings other than those posted on the planning site.