# Irregular room problems

Solved! I just put a crease in the plan I printed off, now it’s skewiffy !!

No, you are absolutely right. My nature is to be a perfectionist but I have come to realize that I don’t have to be that precise with an architectural plan. Thanks for your wisdom, much appreciated

If you really want to be precise get Thomthom’s vertex tools and you can be mm perfect in any direction.

Two years ago I ran into the same problem while doing a remodeling of a house (6m wide and 15m long). Both side walls (15m) were less than 1 degree off the axis (turned inside - like a pie shape). Because in the addition a new kitchen was to be made the measurements had to be accurate up to the mm.

So my suggestion would be (as is what I did with this project) is to create the individual side walls as separate groups ON the axis and then rotate them to the right angle. Refining them will be easy because you’re working on the axis of the group itself.

-Max

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Just sharing a few practical experiences I made when drawing old houses, may that be helpful, either as a hint or a warning…

Why did I come to the conclusion that I could not (fully) avoid small angles

• I had to draw a group of adjacent old houses extending over a field of 70x30 meters for a renovation project
• Typical skew was around 1° to 2°, yielding an imprecision of 45 to 85 cm measured perpendicularly to a length of 50 m (tan(2°)*50m/2) - this is too much when you need to determine where you have enough room for a door, furniture, when estimating surfaces, etc.
• I also had to trilaterate the buildings just to understand the real configuration of the angles - which differed strongly from my perception on the ground. It’s sometimes difficult to notice angles even up to 20°.
• And probably yes, just out of curiosity and perfectionism…

• Keep wall thicknesses constant (to be able to model at least openings easily)
• Keep floors and walls vertical

Problems I faced

• It’s almost impossible to be fully precise
• Also in the vertical dimension, I oversaw for example trapezoidal openings, which can be a problem when you order a door or a window
• @simoncbevans described above common issues that you encounter with SketchUp with small angles
• Drawing the roof on top of non-orthogonal wall is a challenge

How I dealt with them

• Zoomed in closely to the end points of my lines or
• Constantly changed the drawing axes - using short-cuts allows to significantly reduce the time needed for this, this is currently my preferred method (1 tap an 3 quick clicks)
• I used solid tools to trim the walls with the roof

Some other possible strategies

• First construct your geometry precisely in 2D. When you have the full picture, it’s easier to see where you can simplify - do it and only then start modeling in 3D.
• Place the drawing axes across the corners of the rooms (around 45°) to avoid the inference engine working against you.

As a side-note, the difficulty to work with small angles is far from being specific to SketchUp. Think of drawing by hand with a set square. There are reasons why many buildings are orthogonal…

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Wow! Thank very very much and an absolute bargain at 20 dollars

This is a fascinating thread, divided by those who want accuracy and those who want practicality.

Sounds like M. Rier works in France and I work in the UK. We both have an enormous number of very old buildings that are way off square and upright. Are you going to model them to show those irregularities or are you going to approximate to make life simpler?

In the UK, we have to produce drawings to scale for planning and construction purposes. They do need to be reasonably accurate, but not necessarily mm accurate. A deviation of up to 1% might be acceptable. Trouble is, you might need to introduce a deviation of 5% to “regularise” things and that would be unacceptable.

This problem does not occur with new buildings or even new extensions (mostly!). There are nearly 400,000 “listed” buildings in the UK alone and not all old buildings are listed. So those of us working in this field will have to deal with this problem sooner or later.

Personally, I tend to get measured surveys done by firms that specialise and their business is accuracy. So the survey drawings will show all irregularities. I guess I could spend time “cheating” the survey, making lines straight and perpendicular, but that would take time and build in inaccuracies where they don’t exist. It would be akin to taking a high res picture and blurring it. It just seems perverse.

M. Rier and I are probably in a small minority but you can understand us trying to find something that allows us to work in the way that seems most appropriate to our area of work.

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Way off square or 5% is the easy thing - it already matters and it is easy to model.

The 1% is the hard part. It falls within the tolerance of survey drawings or hand-taken measurements. Survey drawings usually introduce new irregularities of their own. New technology like laser scanning also has its tolerances that do not greatly differ from hand measurements. Also, survey drawings are ultimately produced by humans even if based on scanned point clouds. Luckily the 1% errors (like a wall being skewed by 1…3 cm in a small living room usually do not matter in practice.

It is quite the opposite. A surveyor takes a blurry reality and makes his/her interpretation of it and renders it as an absolute image.

Measuring is a fractal process, and full accuracy is impossible to produce, whereas our software is usually inadequate for describing the fuzziness of reality.

Anssi

Indeed I both live and restore old houses in SW France but I am English also. It certainly is an interesting thread but I can’t help but feel there is a lack of appreciation of how irregular old buildings can be. I’ve known opposite walls where one is almost two meters longer than the other and not by design but because they were often created ‘en route’ using little more than the eye to judge things. The funny thing is that to date I have also used a pen and paper to draw out plans and never had any problems connecting any points. I thought I would give SketchUp a chance as it looked fun more than anything and from the outset I have found what appears to be apparent limitations. Still, it’s all good fun and part of life’s learning curves

Thank you for taking the time to respond, your advice is much appreciated.

I’ve certainly experienced all of the problems you faced and it seems that the solution is to just make everything straight and square. As soon as one strays off the path, that’s when you hit a swamp.

SketchUp is a wonderful piece of software even with it’s limitations and I am confident in time and with versions released, the issues I face today will be dealt with. For now, I will just respect those limitations simply because I have no choice.

Ultimately I have no choice but to work within the bounds of the software.

“Measuring is a fractal process, and full accuracy is impossible to produce”. You mean within the limits of SketchUp right? Nowadays we have gadgets and software that will literally scan interiors creating an exact replica of a room/space so the technology is certainly out there and I am sure that one day that will become the standard way of doing the kind of things I’m trying to achieve.

The simple truth is that SketchUp has its limitations and the user just has to work within those limitations otherwise they are opening a can of worms.

You have a too great confidence in technology. As I said, the scanners etc. work within a tolerance that is also dependent on other technology involved, like GPS, and, when the data is converted into usable 2D drawings or 3D models, it is further simplified either automatically or by a human operator, so the result is never 100% accurate but an approximation. By itself the point clouds are enormous files of tens of gigabytes. Even when what you have is a professionally made survey it is best to take your own tape and double-check the really critical points (like where you have to fit in new standardized parts).

The message I am trying to drive home is that creating a model of an existing structure is also a creative process. Yes, even the limitations of the software must often be taken into account. They tend to be similar across applications, as all work best with straight, vertical walls and none have the tools to model all surfaces to resemble the face of the moon.

Anssi

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I think we all should accept that in this instance Schrödinger’s cat may in fact be a dog and move on.

what if you create the rectangle for the room, and use the move tool and the scale tool to move the walls out of square as needed? Only select the walls you want to alter then move them to the shape you want? then use the curve tool to make walls that are bent. The push pull tool will pull them up. It’s been a while since I played with layout - didn’t that have a tool to bend lines with? Maybe go back and forth between the two programs?

G

I think the problem you are having is a basic one, the walls will not autofill because the lines are not on the same plane. I ran into the same problem while doing as-builts of a 14th century house in France. This is an easy fix. Start will a large rectangle and group it. Use this as your drawing surface. Then just look for the inference to tell you the tool is “on face”. Your lines will fill no matter how skewed they are. Also it will help to lay down construction lines before the hard lines with the Tape Measure tool. The program will draw as accurately as you need it to. I will regularly have to draw to a 1/32 tolerance for film props and it works great.