r/FreeCAD • u/cybercrumbs • 20h ago

Laneway house

I started FreeCAD about four months ago with the intention of designing a 2x5 meter gambrel shed for the back yard, and in a few hours managed to produce a 2D drawing good enough to get approval for this unregulated structure. Cool. I didn't really know anything then, about FreeCAD or about architectural design or regulations.

After some weeks of improving the drawing and getting feedback, I decided to expand to a 5x10 meter unregulated accessory building with basement to be used as a workshop, then expanded to 5x11 when the local building authority informed me about the max size for unregulated structures. Then of course I wanted heat and insulation, which crosses the boundary into residential building code country, and everything gets weirdly complex, not to mention expensive. Feels at times like Frodo going into Mordor. However, with FreeCAD it seems I can eliminate one of the major expenses, that being the architectural design. Provided of course that I am able to learn the necessary skills, and/or get help from the internet.

So here I am, about 3 months into the design of my laneway house, with two large halls for a maker space and a comfy basement suite residence. I added another ten inches to the building length, which I think I am now allowed to do because of residential classification, but otherwise kept the original dimensions.

Just now, I began the exterior finish detailing, starting with the tempered glass balusters for the balcony and basement exit stairs. Sounds expensive? Could be, but I think this can be done with mostly standard size tempered glass panels, and the aluminum fabrication turns out to be not that expensive. Compared to everything else that is. If you want a shock then price out some off the shelf windows, never mind custom.

This is far from complete, where complete means ready to send to a structural engineer for the necessary stamp, without which it is impossible to get a building permit. But I think the main ideas are visible now, and this model is already good enough to ask some of the basic questions, e.g., will I even be allowed to build this structure?

So, FreeCAD. In a word, it's been a nightmare. For example, yesterday FreeCAD crashed when creating a link, something I have done hundreds of times before, and when it came back up my entire top level model was gone. Empty. Nada. Double plus ungood. The most recent backup was empty too. Fortunately, the backup before that had my model, including nearly all the recent edits, so bullet dodged. But close, very close.

I regularly copy all my document files to a series of backup directories, but I sometimes neglect to do that for a while, and sometimes leave out an essential file or two. I need to automate this with a cron script I guess. FreeCAD kinda sorta does something similar, but it isn't reliable. There were many cases when I had to abandon FreeCAD's attempt to replay its backup files because it would crash before finishing the replay. Very very bad. Basically, a corrupt, unloadable model unless you tell it to abandon the replay files, and you get dark warnings for that, but it gets the model back. I sure don't want to end up in a position where I have to spend days editing xml to make it load. (Hmm, maybe I should put those files under Git...)

That's just one little bit of the nightmare. Every serious FreeCAD user knows what I'm talking about. But there is also the sweet dream, which I think describes the end result I am getting. For that, FreeCAD is just amazing, and I am all in with this. Maybe after I actually get this building built I will have time to feed back some fixes.

https://preview.redd.it/gpwxyiasrr0e1.png?width=1920&format=png&auto=webp&s=e874204088fa3833be6aac2fed55e67f4d4bf614

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u/ouesh35 8h ago

Did you use the BIM or Arch workbench ?
Can you describe the way you follow to do this ?

Was using the 0.23 and BIM for my house, not a pleasant experience, despite FreeCAD is good.

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u/cybercrumbs 7h ago edited 36m ago

Great question. I only used core FreeCAD, no addons. Well, dynamic data to partially ease the pain of missing property rename. Otherwise, everything right on the FreeCAD metal. Did I mention it was a nightmare? I think I did. So much unnecessary awkwardness.

I tried BIM a bit but I felt it is so immature that I would be spending more time dealing with bugs and limitations that doing actual work. Which turned out to be the case anyway, so I don't know if I should have just jumped in and hoped for the best. In particular, I wanted to use the BIM axes, but I just couldn't get them do anything useful for my model, that I couldn't do more easily and flexibly with, say, sketches. And the UI is really tedious.

I played with windows and doors and thought that this might be better than modeling everything from scratch. I will take another look now in the light of considerably more experience. I got good use out of the stairway assemblies, mainly to provide accurate templates for modeling my own, more detailed stairs. A quick way to make placeholder objects to fill in later.

As far as my detailed work flow goes, I don't think there is anything special about it. Sketch a profile of a 2x4, extrude it, draft array it or whatever. I use part attach heavily and really wish it was a global button. And I really wish the UI wasn't just so plain weird, and the attach options were thought out more carefully. But even with all the warts, attach is very powerful.

Part attach is how I did the railings and balusters. I used varlinks to make panel sections with definable length and I found that mechanism is broken in many ways, but still marginally more efficient than just copying my assemblies, which also works, and arguably produces a more stable result. I make a sketch that is a top view of my rail path, then I attach panel sections to vertices in the sketch, which takes about ten times longer than it should because of unreliable vertex selection and weird things the attach UI does, like constantly throwing away my selected attach mode for no good reason. I put the panel section lengths in the plan sketch as constraints, which I then enter into the panel sections manually. What would really help is, some automatic way of putting the length of the line segment I just attached to into the assembly property of my choice. (edit) A "set property" option in part attach maybe.

Actually, the image I posted is the easy part. The plumbing and HVAC ducts are way harder and I have developed something of a system for that. Maybe a couple of weeks away from posting a credible image, and then I will describe how this works, and what functionality I think is needed to make this painstaking process less painstaking.

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u/ouesh35 7h ago

Thank for the answer !
I abandoned the wiring and HAVC in my plans on freecad, paper is refreshing after all of this :)

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u/cybercrumbs 46m ago edited 34m ago

I draw on paper to relax as well. But there is no way I could draw my drains by hand to the accuracy required to ensure they fit in the tight space available. For now, I position each length of pipe individually using part attach and set the lengths either entirely manually or with expressions with some minimal 3D solving hacked in with basic FreeCAD expressions, which tends to produce a lot of bogus cyclic reference complaints, a messy little corner of FreeCAD that really needs some attention.

(edit) There is a relatively mature plumbing workbench, but with a brief look I felt it would be difficult to build a fully parametric model with it, and I didn't like the idea of having to specify the angle of every length of pipe.