Box with angled walls and roof. How to draw clean

Hello all. Just a beginner on the steep slope of intuitive user interface :wink:
I am trying to draw a box shaped building with no parallel walls, in order to reduce acoustic standing waves.

I have succes in drawing the four walls, with tre angles not being 90 deg, using rotate tool.
But after adding a roof I try to give it a small angle also using the ‘rotate’ tool it messes it up.

I am sure there is a smart way to do it all… Hope to hear from you…

group each face. Then rotate roof as required.

If you dont group each face then SU will drag all the other geometry with it when you try rotate.

Explode if you need to after ward.

Altering the walls to make them off parallel is easy. The problem is getting the roof to sit on the walls once so altered. One way to do it is to first create the walls with a flat “roof”. Group them. Then make a cutter block that is not horizontal but inclined at the pitch of the roof. Group that. If you had Pro, you could then use Solid Tools to trim the wall group with the roof group. As you don’t, you will have to use the Intersect tools and delete what you don’t need.

Here it is with Solid Tools method:

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A good way to reduce acoustic sound waves is to install sound absorbing foam to the walls.

A less absorbent option is a Freestanding Acoustic Panel.

If you’re a beginner, then you can practice moving around objects from the 3D Warehouse. Watch the polygon count to prevent lag. On the 3D Warehouse, they have sound absorption panels and all kinds of stuff.

For exterior sound reduction, I imagine shrubs, trees, grass, and a natural stone brick facade would probably help. I think texture helps reduce sound more than the large-scale shape of the building.

I am not a beginner. It is a reverberant room for using ISO 3743-1 standard.

Make the roof a group, then intersect the model with it. Delete unwanted geometry.

Could you attach what you have so far so we can see exactly what you are trying to do.
Or better still, attach the model before you modified the roof and tell us how you need it to be angled.

I think @BirgerBJ meant they’re a beginner at SketchUp, but proficient at acoustics.

It’s worth noting that you can draw things off angle and keep them planar in 2d but once you work in 3 dimensions you will tend to get triangulation. This can be softened but not deleted.
As you see here I have a non square face pulled up, but then when I angle the top it adds the diagonal, which I soften using ctrl with Eraser.
So you need to look at the actual structure you want to create and adjust the geometry to suit.


Or you can use the move tool for some edges, but as mentioned by Box, you will get triangulation. By moving one vertice in the plane of another face, you can delete the triangulation, if needed…


The example I included in post 3 kept the roof plane but inclined. The @Box and @Cotty versions effectively introduce a ridge or valley. That may or may not be a problem depending on what the OP wants it to look like or his choice of roofing material. Softening the line may make it look like it’s all one surface but of course , it isn’t.

Just to be clear, in the last step I moved the point in the plane of the other face and deleted (not softened) the edge.

So you did. My apologies.

And I’m pointing out triangulation. Rather than slicing.

Doh! How did I not know about that inferencing snap? Thanks.


It’s like a lot of things. You probably knew it at one time but didn’t have any need for it and forgot about it.

Like every time I learn about making wine I forget about how to drive!


Good to hear you made it back home…

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This applies to faces, but also to edges etc. as long as you don’t have anything selected prior to “grabbing” that inferensing snap with [Shift] , only then “grab” the vertex.

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Actually, to be fair, in the past few hours in SU, I’ve just moved dozens of 2D things constrained on axes to surfaces that were all square to the axes, so I’ve been doing surface snap all day. I just wasn’t thinking in terms of moving a point to the projection of an inclined or angled plane.