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Print at Dec 17, 2025, 6:18:10 PM

Posted by Qrystal at Nov 14, 2017, 3:48:06 PM

old home modelling tips
Most of the tips and instructions out there seem to assume a house either has perfect 90-degree corners everywhere, or that such an approximation is accurate enough for the intended purpose. However, when I attempted to model my home using all right angles, it simply wasn't close enough for me.

You see, I knew I didn't know the thickness of all my walls -- only the ones where I could measure through a doorway. I suspected that most of the exterior walls would be much thicker than the interior walls, especially since it appeared the brick on the front part of the house was a veneer added after the original build. There was also an extension built several decades later than the rest of the house ('70s vs '40s), which also contributed to my uncertainty about wall thicknesses. I was hoping my wall measurements would be able to help me figure out the wall thicknesses more precisely, but the out-of-square corners were throwing everything off. I had thought about getting an angle measuring tool, but knew I should be able to apply my love of geometry to figure it all out. I just needed to figure out a good process to do this, so I could get my model to be what I considered "good enough" to feel confident in designing shelving and choosing furniture.

I tried searching for tips on how to resolve these difficulties, and I must say that I learned a lot from what I read -- I'm smiling at you, helpful forum contributers! :) However, I did not quite find anything that clearly outlined a process that would alleviate the difficulties I was having, so I came up with my own process, which I decided to share here in case it is useful to others. (I also welcome any suggested refinements to my method.)

My Process for Modelling an Older Out-of-Square Home with Unknown Wall Thicknesses

I started by drawing out the walls in their approximate shape, using right angles wherever that seemed to be the builder's intent. For the different parts of the house that I thought would have different wall thicknesses, I used a different pattern on the top edge of the walls in the 2D plan, in preparation for changing them later if/when I found evidence that I should refine my original estimates. I also added doors, windows, light fixtures, built-in shelves and cabinets, and anything else that should be treated as "fixed in place", all in their approximate positions.
Then, I carefully put dimension lines for absolutely everything, without worrying about lining up the actual walls or elements quite yet, just the dimension lines (and I zoomed in very close to make sure those lined up with each other). Here's what I mean by absolutely everything:
- lengths for all four (or more) walls, or if I couldn't reach the walls easily I would measure the floor dimensions, in two places as far apart from each other as possible per dimension;
- distances to doors/windows/light fixtures from room corners, as well as the widths of such elements;
- ...basically, I measured distances between everything that was fixed in place in the house, in all four 2D directions, never assuming that things opposite to each other were symmetric.
Next, I shifted the walls and other elements into better placement, using the dimension lines as guidance. When I noticed things weren't quite fitting, I adjusted either the wall thicknesses or wall angles or both, until everything fit the dimension lines. I also had to shift the dimension lines when I shifted some walls, of course, but I was careful not to change the length of the dimension lines in any of the moves. I was also very careful to keep dimension lines aligned even at the closest zoom level; the more careful I was with this, the easier it was to make the entire room fit the dimensions I had measured. (I did have to re-measure occasionally, but discovering these mistakes made me happy, because it meant by process was working!)
I continued through the house, repeating these steps room by room, and lining each room up with the previously modelled ones, delighting when everything was finally working out. I tried not to be too perfectionistic about it, but there's something so inherently satisfying about having measurements line up, so I indulged that desire in what I hope was a reasonable amount. I made assumptions as necessary, and remembered to refine those assumptions when actual measurements gave me reason to do so.

TL;DR: The key to my process was the realization that dimension lines can be used as tools, rather than for merely providing information to include in a printout. We can simply treat dimension lines as being the fixed elements, and adjust the walls until they agree with the measurements indicated.

I hope that is helpful to someone! Heck, it has already been helpful to my just to make this outline for myself, so I can be even more clear in my process as I continue onward. Cheers~!
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@}-,-'- Qrystal -'-,-{@

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Dec 17, 2025, 6:18:10 PM