Modeling
About Archicad's design tools, element connections, modeling concepts, etc.

Roof / Wall Connection

Bob Moore
Enthusiast
I've just begun working in AC 18 and notice a odd thing about the roof connection. In my attachment you can see I have a single shed roof with bearing at the top outside corner of the wall below. Although this is the pivot point AC 18 eliminates part of the roof and lines up the top edge of the roof with the face of the wall. You really can't build this(and if you did you would have water problems). Since the top outside face of the wall is the pivot point why doesn't AC rotate the wall from there? I know I can work around this but it would be unnecessarily cumbersome. Am I missing some setting quirk?

Thanks.
AC 7 - 27

iMac 27"

Mac OS Sonoma 14.0

3.1 GHz 6-Core Intel Core

32 GB 2667 MHz DDR4

Radeon Pro 575X 4 GB
10 REPLIES 10
Anonymous
Not applicable
Select the roof (in plan or 3D view), click on the edge then use the pet pallet to make that edge vertical.
Bob Moore
Enthusiast
I don't want the edge to be vertical, I want it to slope. I trying to get the pivot line to be the roof pivot point.
AC 7 - 27

iMac 27"

Mac OS Sonoma 14.0

3.1 GHz 6-Core Intel Core

32 GB 2667 MHz DDR4

Radeon Pro 575X 4 GB
Anonymous
Not applicable
Drag the roof across in section then. Pivot line will be off wall line, but does that really matter? It is only an abritary point.

Or, if it does matter, draw a line in section from the (lower) corner of your roof, horizontal, to the wall edge. Cut and paste this line into plan view and offset the edge of your roof the same distance as the length of the line. Use the line as a reference, don't just input the numbers. Then go back to section and it will be in the right place.
Barry Kelly
Moderator
The problem is that the pivot point is on the bottom surface of the roof but the extent of the roof and the angle for the edge uses the top surface of the roof.

As Stuart mentioned if you want to leave the pivot line on the edge of the wall you need to work out the roof offset (overhang) that you will need.
You can measure the distance but it will not be perfectly accurate as you will be missing the decimal accuracy that you will only get if you draw a line and copy & paste it, then use that line as a reference to stretch the roof overhang as Stuart mentioned.

Image attached for clarity.

Barry.
One of the forum moderators.
Versions 6.5 to 27
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11
Bob Moore
Enthusiast
Thanks, Barry & Stuart.
That's what I did as a work around. I seems to me a setting in the roof dialog box should allow you to do this in the set up. This leaves a gap in the roof gable centerline that has to be patched.
AC 7 - 27

iMac 27"

Mac OS Sonoma 14.0

3.1 GHz 6-Core Intel Core

32 GB 2667 MHz DDR4

Radeon Pro 575X 4 GB
Barry Kelly
Moderator
The finished product.
If you have a zero offset in your roof you will need to type any figure in so you can stretch the roof edge rather than the pivot line (i.e. you have to separate them to select the roof edge).

Barry.
One of the forum moderators.
Versions 6.5 to 27
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11
NCornia
Graphisoft
Graphisoft
Hello Gents,

I have taken note of this post and will put it to the attention of our product team.

Best regards,
Nicholas Cornia
Technical Support Team - GRAPHISOFT North America
ARCHICAD on Twitter
Tutorials
GRAPHISOFT Help Center
Bob Moore
Enthusiast
Thanks, again.
AC 7 - 27

iMac 27"

Mac OS Sonoma 14.0

3.1 GHz 6-Core Intel Core

32 GB 2667 MHz DDR4

Radeon Pro 575X 4 GB
Barry Kelly
Moderator
NCornia wrote:
Hello Gents,

I have taken note of this post and will put it to the attention of our product team.

Best regards,
Thanks Nicholas,
It is also related to the fact that the multi-plane heights are also calculated from the top surface - I guess understandably because that is how we see them in the plan view.
But this seems crazy to me as I know where the pitching points are and at what height on the underside surface of the roof as that is the part of the roof generally sitting on a beam or support.
Where it is on the outside means absolutely nothing as it varies depending on the pitch and thickness of the roof.

Barry.
roof_multi-plane_height.jpg
One of the forum moderators.
Versions 6.5 to 27
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11