topic Re: AC21 Autotext in Documentation

AC21 Autotext

Anonymous — Thu, 06 Feb 2025 12:19:30 GMT

I'm trying to set an autotext label in AC21 to give the net area of inside of exterior walls for insulation calculations, but it is proving to be difficult.
I have drawn out a box of walls 5x5x5ms to be simple, place the label set to "Net surface on the inside face"
I place a label on the wall, but it does not give the correct area, in fact when I place the same label on all 4 walls I get different results.
Can somebody put me right please.

Re: AC21 Autotext

Barry Kelly — Tue, 03 Apr 2018 01:57:20 GMT

It probably is correct.
Look at how the walls connect in 3D (select them in 3D to see this).
The 'Net' area takes into consideration the connections.
You will find one wall is not cut at the ends at all, 2 walls will have one end cut by the others and the fourth will have both ends cut.

You might need to look at a surface area schedule rather than an element or component schedule.

Barry.

Re: AC21 Autotext

Anonymous — Tue, 03 Apr 2018 09:40:36 GMT

You are about right Barry, but the schedule gives the same result

Re: AC21 Autotext

Erwin Edel — Tue, 03 Apr 2018 13:56:45 GMT

You should be able to schedule the exposed area, which is what you are looking for. Create a schedule for SURFACES.

Re: AC21 Autotext

Anonymous — Tue, 03 Apr 2018 20:48:02 GMT

Ok, i have tried all the fields with surface, but cannot find anything with exposed surface, where will i find that.

Re: AC21 Autotext

Barry Kelly — Wed, 04 Apr 2018 01:29:27 GMT

Make sure you create a 'Surface' schedule - not an element or component schedule.

Then you will see fields for 'Surfaces'.

If you want to schedule a particular surface then you can add that as a criteria.
If you don't do that you will get all the surfaces of the wall.

You need to make sure the inside, outside and end surfaces of your walls are all set correctly.
If you are not overriding the surfaces of your walls then you need to make sure your composites are all using the correct building materials.

Barry.

Re: AC21 Autotext

Anonymous — Wed, 04 Apr 2018 08:39:42 GMT

Thanks Barry, but how do i need to set the walls? As i am still getting the same results.

"make sure the inside, outside and end surfaces of your walls are all set correctly."

Re: AC21 Autotext

Barry Kelly — Wed, 04 Apr 2018 08:57:16 GMT

I find you have to override the wall surfaces to get the results you are looking for.
If you don't override the surfaces (so it is using the building materials) then you will still get some slight discrepancies because of the ways the walls connect.
I don't quite understand this discrepancy myself (I haven't really investigated it).

Barry.

Re: AC21 Autotext

Anonymous — Sat, 07 Apr 2018 21:34:24 GMT

Still doesn't work Barry. did it work ok for you?

Re: AC21 Autotext

Barry Kelly — Mon, 09 Apr 2018 01:35:43 GMT

Rogerdodge wrote:
Still doesn't work Barry. did it work ok for you?

Yes.
One of my earlier images shows an 'exposed' area of 25m² for all four walls, and you can see the other surface areas all vary as you are finding.

Barry.