Sketchup losing its right angles

Hi folks, I’ve been designing a garden shed in Sketchup.

I’ve copied and rotated a vertical member so that it becomes horizontal (well, it’s a sloping roof so about 3 in 12), and laid it across the top of my shed as a roof rafter.

The problem is, although I’ve located one end corner flush against the top of my top plate, the other end isn’t flush with the end of the opposite wall. It’s as if Sketchup has decided to just add a couple of degrees to the angle of the rafter so it’s toed out against the wall.

Everything lined up fine previously so there’s no error in the squareness of the model, it’s only now I’ve decided to change the pitch and changed the height of my top plate on one side that Sketchup has apparently decided my building isn’t square anymore.

Has anybody else encountered this bug and can advise? Currently, I can’t see any way forward but to scrap the whole thing and start again. With a dozen hours invested so far, I’d rather not have to do that.

Has Sketchup offered to “fix” your model?
Can you share the file so someone can have a look?


This sounds like a problem with the way you are creating the model. SketchUp won’t arbitrarily realign components or groups. If you would like some help sorting out your model, upload the SKP file.

I assume that Sketchup aligns stuff with the three major axes when it snaps to them, that’s the way it’s worked so far! So if I have a member that is vertically oriented but aligned to the axes, and I rotate it around one of those axes, I expect it to stay aligned to the plane of rotation.

In the attachment, you can see that the (only) roof rafter in the model isn’t flush to the lower top plate, even though it’s flush at the other end. I created the rafter by copying the vertical and rotating it around the green axis. I would expect it to stay aligned with the red axis. But it hasn’t.

Thanks for the help with this folks.

Shed v2.skp (3.0 MB)

Some errors have crept into the model perhaps because you are using snap to length ( 1/16" ).
Zoom in close on the end opposite the rafter and you can see some problems.
Still looking…


Here’s some more at the lower right.

Try a setting of the style with edges by axis. To make life easier do your modeling without textures or shadows on…

You have a several studs that are square but they are all tilted from the model axis. There is a good one on the front wall at the partition. Make it a component (that might save time later) and copy to the end of the wall bottom plates. Realign the top plates to the new stud and see how this aligns with the
back wall. Then just replace those studs and check other alignment to the upright studs.

If you are looking for total accuracy --you have some overlapping / misaligned lumber at the center of the building.

Your rafter is also not aligned on the red axis. Draw a red axis line off one top end corner and a blue axis line (plumb line) up from the lower corner -they won’t meet. The rafter can be rotated from one end using the blue rotation setting so that the other end corner aligns with a red axis line.

Looks like you’ve already been given some competent direction. I also see the poorly aligned groups. These things make me curious about your work flow. From the evidence it could clearly be improved.

Thanks folks, appreciate all the help here. I’m not going to claim to be a Sketchup expert, I’m sure my workflow could be improved and I still find the tool a little quirky, for all its power. However I have been really careful when creating, to immediately create groups of my extruded rectangles, so they remain square in all directions; and also when moving or rotating, to make sure that the item snaps to an axis or another piece of the model. Clearly I’ve missed a few.

It sounds like I do need to start from scratch; so be it. What I don’t understand is in the previous version of the model, all the rafters lined up perfectly, and all I’ve done in this version of the model is drop the lower wall plate to get myself some extra timber storage in the roof space.

Once again, thanks for your help.

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How did you do the drop of the plates? To me it looks like most of your groups are lined up square and you need to replace a few. Then snap the different parts into place so they aligned. Redraw or realign that rafter. So you don’t have to start all over.

To be honest this often leads to off axis issues because there is a certain ’ tolerance ’ in that setting that doesn’t guarantee things are actually on axis. It’s useful for showing the axis orientation but unfortunately cannot be relied on for total accuracy.


Spend some time at THE LEARNING CENTER viewing the Sketchup Fundamentals. It is a great resource.

I see enough problems with your model that I think starting over would be easier than trying to fix them all. You have a number of pieces that have oddball sizes and chasing around to fix all of them will be a lot of work but you’d need to do that before you start working on getting all of the parts aligned correctly.


You could make your modeling a whole lot more efficient if you would utilize components instead of groups. It also appears that you are drawing a part, making it a group and then moving it into place in the project. It would be a much easier and more accurate if you would model parts in place as much as possible.

Before you start, turn off Length Snapping and set Units Precision higher. I always set precision higher than I would use in real life because that makes it easier to detect errors. I set Precision to 1/64th in. in your model. Running a cutlist as I show above makes it easy to see parts that need some attention. Of course since they all bacsically have the same name, it’s till a challenge to figure out which one is which. If you use components and give them useful names, you can easily pick them out of the list if they need correction.

I have started to redraw your shed. I’ve modeled the parts in place using components instead of groups. I’ve copied components where appropriate and used Make Unique as needed. The first instance of a component was drawn in it’s final resting place.

And the cutlist for what I’ve modeled so far.

I think you’ll get the hang of this and find that it goes much more smoothly.

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This is the most efficient way to see what is happening in this model, not necessarily a way to model in general.

Thank you - most of my learning has been from YT vids which are fine but tend to teach features in isolation.

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