topic Re: How would I create an angled plane to draw on? in Revit Architecture Forum

How would I create an angled plane to draw on?

ivanonJCM28 — Fri, 18 Jul 2025 04:32:58 GMT

Hello!

I'm trying to model a version of the House of Grain in Denmark, but a couple parts of the roof have been giving me some real issues. There are a couple of flat roof segments that slope in two directions, and I haven't been able to figure them out. You can see one pretty clearly on the left side of image 1/17 in the linked gallery, and you can see the other one on the right side of image 6/17. There's also a decent view of them from above at 0:07 of this video. I'll include a version of my file in this post as well in case that's useful.

So far I've mainly been working on them as footprints (though I did give extrusions a shot), and I've focused on three methods:

- Modify Sub Elements seemed to get the closest in one sense, but it felt really unstable and imprecise, and it seemed to sort of warp the thickness of my roof in an odd way. I'd like to avoid it if I can.

- using Boundary Lines to define the slope worked really well in one direction, but not two - picking two lines just created a peaked roof.

- Slope Arrows were similar - worked really well to slope the segment in one direction but I couldn't figure it out in two directions.

I've heard that I might be able to create a reference plane that is parallel to the plane of the oddly-sloped roofs, and then sketch out my footprint on that. But I'm not sure how to go about that and I'm not even totally sure what I'd want to google to figure that out. Can anyone describe how to use this technique or give me a few keywords? If there are any other methods out there, I'd be curious to hear about them.

Thanks very much!

Re: How would I create an angled plane to draw on?

_Vijay — Fri, 18 Jul 2025 05:04:18 GMT

To answer your question, you can create an inclined reference plane for the work plane. However, in this situation, how about creating the roof by extrusion and cutting the unwanted parts?

Re: How would I create an angled plane to draw on?

ivanonJCM28 — Fri, 18 Jul 2025 15:17:57 GMT

Thanks!

For now I'm trying the inclined plane option. So far I've been able to set a plane at one angle (pics 1 and 2), but I'm not sure how to set one at two angles so as to be parallel to the roof face. Do you have and suggestions for how I might do that? Is there an option to define a plane using points or something similar?

pic 1

pic 2

I hadn't considered your second solution! For that approach would I create a very thick roof profile and then use in-place massing to cut out the right shape?

Re: How would I create an angled plane to draw on?

kostask_oionei — Fri, 18 Jul 2025 16:21:57 GMT

Hi,

A Roof by Footprint must be drawn on a Level (always horizontal) and will be associated with that Level.

When you try to draw on a non-horizontal work plane, you receive the following message:

To draw a roof on a non-horizontal work plane, you must use the Roof by Extrusion option. The roof will also be associated with the Level you select.

Instead, I would use the Roof by Face option. This is most easily achieved by first creating a mass and applying Roof-by-Face to the surfaces of the mass. The mass can be created however you like.

Re: How would I create an angled plane to draw on?

ivanonJCM28 — Fri, 18 Jul 2025 17:34:51 GMT

That worked, thanks very much! I've spent a long time trying to figure this out, and it's fantastic to finally be a bit closer.

I have one other question, if you have time. It seems as though I can't attach the walls to this roof in the same way that I can with others:

Is this something to do with the void workflow, or should I start another topic for this? Sorry if this is a pretty basic question - I'm still in my first few weeks of the software.

Re: How would I create an angled plane to draw on?

kostask_oionei — Sun, 20 Jul 2025 18:00:07 GMT

Hi,

I don't know, maybe you should start another topic for this.

But before try to disjoin the walls. Click on the little icon like "T" both left and right side. Then try that the wall length is the same with the roof.

Then try again attach top/base option.

Try also the wall by face option.

Sorry I don't have Revit right now for screenshots.

Re: How would I create an angled plane to draw on?

ivanonJCM28 — Mon, 21 Jul 2025 18:07:46 GMT

Will do! Thank you.