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

rooflights in flatroofs

Anonymous
Not applicable
hi!
when trying to place a roolight in a roof with only 1.5 degree fall, I get an error message something like --'roofs below 20 and above 40 degrees need special solutions'.
What's the special solution then?
How do I place the rooflight without the roof getting all 'messed-up'?
many thanks
jonathan
11 REPLIES 11
Karl Ottenstein
Moderator
bell63 wrote:
hi!
when trying to place a roolight in a roof with only 1.5 degree fall, I get an error message something like --'roofs below 20 and above 40 degrees need special solutions'.
What's the special solution then?
How do I place the rooflight without the roof getting all 'messed-up'?
many thanks
jonathan
The problem is the angles that ArchiCAD cuts on the four sides of the hole for the skylight (rooflight). This is a long standing complaint. If the skylight tool cut perpendicular sides for all four sides, and then had the user adjust the angles to their needs, there would be no problem at all.

The problem is the angles the ArchiCAD uses for the top edge and bottom edge of the hole that is cut in the roof. (The sides are both plumb cut.) These angles do not correspond to any standard practice in the US ... so I assume they are some European standard. If not, then GS should fix this.

So, here's the "special solution" (workaround):

Change the pitch of your roof to be steeper than you intend so that you can insert the skylights without the error.

Now, select the roof (only). If you are 9.0, it does not matter what tool is selected. In earlier versions, select the roof tool. With the mercedes cursor on any skylight hole edge (if you are changing all), or on the top or bottom edge (if you are only changing those two), select the edge angle button in the pet palette as shown in the attached screenshot. Make the edge (or all edges) perpendicular.

Finally, change the pitch of the roof to the pitch that you originally wanted.

NOTE! Any new skylights placed in the roof will exhibit the error ... and you will have to repeat the above on them ... so it is better to place all skylights first, and then fix them. Once you've done the above steps, you can drag the skylights to where they belong and fine-tune the angles of the holes in the roof.

Karl
skylight-edges.gif
One of the forum moderators
AC 28 USA and earlier   •   macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB
Anonymous
Not applicable
many thanks Karl!
I had read your earlier postings on this subject but couldn't make sense of it all until this reiteration.
thanks again
yours
jonathan
Link
Graphisoft Partner
Graphisoft Partner
So, here's the "special solution" (workaround):

Change the pitch of your roof to be steeper than you intend so that you can insert the skylights without the error.

Now, select the roof (only). If you are 9.0, it does not matter what tool is selected. In earlier versions, select the roof tool. With the mercedes cursor on any skylight hole edge (if you are changing all), or on the top or bottom edge (if you are only changing those two), select the edge angle button in the pet palette as shown in the attached screenshot. Make the edge (or all edges) perpendicular.

Finally, change the pitch of the roof to the pitch that you originally wanted.
I "believe" you can simply place the skylight without changing the pitch, and make perpendicular just the angle on the upper side of the roof hole.

Cheers,
Link.
Karl Ottenstein
Moderator
Link wrote:
So, here's the "special solution" (workaround):

Change the pitch of your roof to be steeper than you intend so that you can insert the skylights without the error.

Now, select the roof (only). If you are 9.0, it does not matter what tool is selected. In earlier versions, select the roof tool. With the mercedes cursor on any skylight hole edge (if you are changing all), or on the top or bottom edge (if you are only changing those two), select the edge angle button in the pet palette as shown in the attached screenshot. Make the edge (or all edges) perpendicular.

Finally, change the pitch of the roof to the pitch that you originally wanted.
I "believe" you can simply place the skylight without changing the pitch, and make perpendicular just the angle on the upper side of the roof hole.
You're right, Link! You can just put up with the error message and then change the upper edges of each skylight. 😉

Karl
One of the forum moderators
AC 28 USA and earlier   •   macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB
Djordje
Virtuoso
Karl wrote:
Link wrote:
So, here's the "special solution" (workaround):

Change the pitch of your roof to be steeper than you intend so that you can insert the skylights without the error. ///Finally, change the pitch of the roof to the pitch that you originally wanted.
You're right, Link! You can just put up with the error message and then change the upper edges of each skylight. 😉
Mhm ... quite fast when you have 120 of them 😉

NOT!
Djordje



ArchiCAD since 4.55 ... 1995
HP Omen
Karl Ottenstein
Moderator
Djordje wrote:
Mhm ... quite fast when you have 120 of them 😉

NOT!
Yikes!! OK. Back to my first posted workaround then...

Sigh.

Karl
One of the forum moderators
AC 28 USA and earlier   •   macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB
Anonymous
Not applicable
I'm trying to place a skylight object (Skylight Pyramid) in a flat roof, and I keep getting an error message about the skylight being outside the roof area. The skylight is placed, but it doesn't cut a hole in the roof, and isn't linked to it.

I think it's got something to do with the base height of the object, but I can't work out what it is...

I've tried setting the base height of the skylight to the base height of the roof, as well as the top height of the roof, neither works.

In 3D I can see that the skylight is at the correct height when it's base height is the same as the roof's top height.

I could just plonk the skylight on, and cut the hole myself, but I'd like to get to the bottom of this...


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Update
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I just went back to the skylight, syringed it's settings, and placed a new skylight in the roof - and this time it worked BUT, it is now at 90 degrees to the first one.

So now I have two skylights in the same roof, one as an unlinked object, and the other linked to the roof. Both identical except for the linked one is at 90 degrees to the unlinked (and I haven't set the angle on either, just used the default).

very confused.
Djordje
Virtuoso
Tom wrote:
I'm trying to place a skylight object (Skylight Pyramid) in a flat roof, and I keep getting an error message about the skylight being outside the roof area. The skylight is placed, but it doesn't cut a hole in the roof, and isn't linked to it.
Is your flat roof done with the ArchiCAD roof tool, or as a slab?

Do it with the roof, and slope it a teeny weeny bit - even flat roofs do really have slopes, right? - and it will cry that the slope is less than whatever it wants it to be, but it will cut the hole. Edge angle adjustment will be necessary.
Djordje



ArchiCAD since 4.55 ... 1995
HP Omen
Anonymous
Not applicable
Yeah, my flat roof is made with the roof tool, and at 5 degrees (I've tried at other flattish angles as well). After trying several times, I get different results, and there doesn't seem to be any reason for these differences. Some times the skylight goes in fine, some times it tells me it's not inside the roof plane, and sometimes it appears to work, only to find that it hasn't cut the hole in the roof.

I guess what I'm really after are the 'rules' for placing a skylight. The ever helpful GS manual tells me I simply have to place the skylight inside the roof plane, which simply isn't true, there seem to be a whole lot of secret variables...