View port scale

When setting the viewport scale how do I know if I'm scaling to an A3 plot or A1 etc.

You don't. The size of the paper is set in the Page Setup Manager (right-click on the Layout-tab).

That's brilliant thanks for that, just one more thing how do I make the viewport fit the A3 layout

After you have done the settings in the Page Setup Manager, what you'll see on the Layout-screen is the actual size of your paper. So you can create your viewport and see instantly how it looks on an A3. What scale to use on your Viewport depends on what you are drawing.

For example, I have a house on a property that I have at scale 1:100 which I find suitable for my needs.

That's as helped me understand it thanks, just one more thing how do I set my company border up as the viewport

There are different schools of thought on this, both of which are valid. A matter of personal preference. I would suggest moving your SHEET into your paperspace LAYOUT, and having done that, place your viewport or viewports on the sheet, so you can see how it all works together.

By sheet you mean place the company border (block) into the paper space and then create a viewport inside the company border

Exactly what I mean.

Brilliant so helpful thank you

Make sure your company border is at 1:1 size A3 420x297 then your viewports are scaled not the sheet.

A little metric trick with the viewports toolbar on on right side when you click in a viewport a number will appear for auto scaling enter the correct scale number.

10 = 1:00 4 =1:250 5 = 1:200