Hello! I’m having an issue with creating (what feels like) an impossible layout.
The layout is of a 3-story chalet, with the upper level featuring the typical chalet-sloped roof. The issue is that the wall on the west side is not at 90 degrees. Additionally, the west wall is 175cm high, while the east wall is 193cm high. The highest point in the chalet is 270cm.
I’ve had no issue with the east wall, since it’s a straight wall, but the west wall is giving me a lot of issues.
I’ve tried creating the roof, and then using the intersect with model feature, but I can never seem to get an equal height on the west wall; there’s always a variation of ~10cm from front to back.
For context, I’m attaching an image showing a 2D elevation of the north side, as well as the SketchUp file.
Is this something that can be fixed with such irregular walls? I’m wondering whether I should spend so much time trying to have the model with the perfect dimensions…
You need to start with something for reference. Is the ridge parallel to one of the long sides? Is it a know distance in plan view from one of the long sides that it is parallel to? Is it centered in the building? Or offset due to the walls being out of square?
Are both sides of the roof at the same pitch?
Are the gable ends square with one of the long sides?
Depending on what your reference points are determines how you model the roof, and then let the walls get clipped as they need to under the roof.
If the walls and the roof are both skewed and do not have a clear and easy reference / relationship to one another… then that makes it difficult - and I would need to see far more ‘as built’ dimensions to how it is built.
Hey Mike, unfortunately, I don’t have every single dimension of the space for the time being, but I’m attaching what I have from the architect (with the floor plans at the bottom being the final ones).
From what I can see, as I built the model, the walls and the roof are both skewed, and there is no clear, easy reference between them. I hope the document I’ve included gives you the insight I am missing!
The architect has failed to draw reality. If you put a pitched roof onto a non-rectangular floor plan, then something has ‘to give’.
If the eaves remain level on both sides as drawn, then the ridge cannot be level if the roof slopes are both in a single plane.
If the eaves are both level and the ridge is also level, then the roofs cannot have planar surfaces - they must ‘twist’ to work. Given the small difference in the plan this twisting might well get hidden in the tiling courses, but setting out the rafters and their battens will be a PITA.
If both of the eaves are level and the roof planes are not twisted then the ridge cannot be level - however, with the small dimensions involved the tiling gauge could be tweaked to avoid an awkward any visibly tapering course at the ridge [or eaves].
If one of the eaves is level, and the ridge is also level, and the roof planes are also not twisted, then the other eaves must slope - again the tiling gauge could be adjusted to hide any tapering course.
So the architect needs to make some design decisions - if it’s new-build, or give you more useful info, if it already exists.
Depends on where you personally fit into the project.
Are you just doing a 3D model for illustrative purposes or shop drawings for the builder, fabricator, etc. where the dimensions need to be quite accurate?
I have encountered this issue previously, and it typically originates from Designer’s running 2D software with a less than informed understanding of geometry. Only when you show them the 3D model do they being to understand the various implications mention in the posts above e.g. sloping ridges. Perhaps you could share a basic 3D model with your client to help them understand your concerns.
Thank you all! This is indeed for illustrative purpose only and therefore maybe it doesn’t make sense to have the model to the exact cm! The height on one side does vary 10cm, so maybe that’s just something I’ll need to highlight to the client.
If you are just making an image and a roof-tile textured material will suffice, then it’s an easy ‘bodge’. Make the roof using three level lines of the eaves and ridge, draw in verge lines along the gables. It won’t face automatically. The crudest way to force a face is two draw in a diagonal and get two triangles for each roof face. To get a smoother surface divided the lines into equal parts [context menu] and ‘stitch’ them together adding diagonals to form smaller triangles. One you have the faces use the smooth tool to hide the dividing edges and apply the tile material to the whole of each smoothed roof surface, adjusting the Texture as needing to get the best look…
I get this all the time with my glass extensions. Basically just choose which line you are building off and everything else just intersects where it does. You’ll often find the roof is slightly higher on one side and the plan profile wont have all 90 degree angles.
My nephew’s father (other side, not my brother), who is an architect, designed a house for him that had no two sides parallel, no eaves level. The builder grumbled that it was the most difficult roof he had ever dealt with.
p.s. after having looked at op’s original post and the pdf from the architect my conclusion was that he (the architect) was somehow convinced that 2+2 could be 5. @TIG gave a thorough analysis in his first post why that would never happen.
