Help modeling roof form

Hi, I need some help in modeling a roof on a not square house. I tried everything (I think) but I can’t find the solution.
Perhaps somebody already had this problem?

Many thanks
ROOF~.skp (332.0 KB)

add a ridge line, then divide by number (rafter centers), to fascia and ridge lines, then stich the roof with a rafter line and a diagonal. Then smooth the result, this will give a close approx to the curved roof. Alternately you can rake the pitching points to create a roof with a constant pitch

What are you going to clad the roof with? It is important to know because some materials would be unsuitable (corrugated metal, for example).

It isn’t easy to create the surface you want because it won’t be a flat plane. If you were using relatively small roof cladding such as plain tiles, you could achieve it because lines of battens would effectively be bent and the tiles could be jiggled to suit.

There is the (very old) joke about the Irishman asked for directions who replies: “If I were you, I wouldn’t start from here…”

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This would give you a flat plane to each slope which would allow you to use sheet materials. Tiles too, but there would be some funny cuts.

The obvious question is why anyone would make their life difficult by starting with a shape that is inherently difficult to roof over. But that’s begging the question, I know.

ROOF~.skp (335.8 KB)

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I reckon you could try something like this, and have uniform slopes. At least this way all the rafters would be the same.


It’s an existing old house in the south of France and I’m doing the interior decoration so I don’t clad it. It’s just to have the interior ceiling.

Thank you!!!

I presume what you call the ceiling is in the plane of the roof then?

If it’s the south of France and old, it is quite likely to have Roman tiles. Like plain tiles, they can be adjusted a bit to fit a non planar roof. Effectively, your rafters will be at a sharper pitch near the smaller gable and gradually increase in length and pitch as they approach the other.

Bonne chance!

See this SU file for ideas.

Roof corrected.skp (603.7 KB)

See this SU file for another way.

Roof 2.skp (602.8 KB)

After looking at your model from a Top View, I see that the building is not symmetrical as per my Roof 2 model.

Here is a corrected one using the same procedure.

Roof 3.skp (583.6 KB)

Hi thank you so much. This is what I was looking for. Did you use plugins to do it??

No. Dead easy without.

Ok must have missed something. Thanks though