Dimensioning a Bathroom with Google Sketchup

In another example of Andy finally gets around to using something he bought a book about, I’m using Google Sketchup v6 to work out some dimensions in a bathroom we’re upgrading. This is partly an exercise in saving money, as the Ceramilite sheets we’re gonna use are expensive. It’s also a training exercise for me before modeling the entire library. This lengthy post discusses the SketchUp features I used for modeling the bathroom, complete with pictures.

The Final Model

Available here

Final Model

Google SketchUp for Dummies (Sk4D)

I don’t buy many for Dummies books and am not a fan of some aspects of their design but this is a very easy book to read. The only annoyance, understandable for production reasons, is the traditional use of color plates.  A tool like SketchUp makes very intelligent use of color for hinting and you swiftly find yourself flipping to the middle of the book and back.

Aidan Chopra’s accompanying website includes many links to videos published on Youtube. The ones with voice-over are particularly useful, which is probably a good reason to navigate from his site rather than just searching Youtube.

SketchUp Features I Used

The fact that I highlight something here probably reveals more about my ignorance than anything else but I thought people tackling such a task might find these interesting. The order below is the order in which I thought of points to make as I encountered issues, starting with a clean page. Remember this is starting as a beginner, yawn when you feel the need 😉

Using your Mouse – Shortcuts for Manipulation

From the start, Sk4D emphasizes the need for a mouse with scrollwheel to take advantage of navigational shortcuts which work regardless of your current tool, saving a lot of time as you dance around your model:

  • wheel alone – zoom
  • hold wheel down (button-mode) – orbit
  • shift-hold wheel down – pan

Entering Dimensions

One of the things I love about SketchUp is that it has a live dimension box in the bottom-right corner of the status bar so at any time whilst you are drawing, you can just type dimensions and hit return and it resizes whatever you are drawing. If you are drawing a rectangle, it shows a comma-separated pair of values in that box and you can enter a pair to override.

Texture Painting – Fill some areas early

The Paint bucket in Sketchup includes a set of basic textures. You might think of adding textures as a fancy thing to do later but I found it dramatically helped in orientation to have the tiled floor area shown with a tile texture, as soon as I had the box-like bathroom outline constructed.

Adjusting Dimensions

SketchUp is not a CAD package and doesn’t retain an object-oriented view of things once created, components being a slight exception At this basic level, it’s about edges and faces. You can use the Move/Copy tool to move a line but the dimension box shows the amount of movement of that line rather than changes to an object dimension.  Using Tools – Dimensions allows you to add classical dimension markings to your drawings and the snap-to hinting makes it extremely easy to position these along one side of a shape you’re resizing. The dimension marking will track one of its endpoints being moved if you drew it from one endpoint to another and so provides dynamic feedback on your resizing, as well as an essential visible dimension.

Adding a Dimension along one edge

SketchUp Quirks

Negative Dimensions

Something very weird happens when you draw in a direction which is negative. Right now I’m trying to draw a rectangle to represent a bath and the dimensions are shown as 1650, -1069. I want the width to be 615mm so I type in 1650, -615 and the rectangle jumps to the left. There’s a minor bug it appears in that the displayed sizes are sometimes negative but anything you type in has to be positive to be to the right of your anchor point. I suspect it is a display bug rather than an entry bug.

Drawing Dimensions to non-EndPoints

The inferencing engine provides lots of colored rectangles and tooltips to tell you when you have reached endpoints, midpoints or are on a line etc. This normally makes it trivial to measure along an edge from one endpoint to another. However, one awkward situation is when you want to measure from a corner of a window vertically down a wall to intersect the base at some point which has no particular meaning – it’s just the place where the measurement is perpendicular. After about 15 minutes of fiddling and looking at videos I gave up and just drew a line. This helps hugely – drawing a line will lock to drawing on one of the coloured axes, so you can guarantee it is perpendicular, and then will terminate properly at the bottom. You can attach a dimension to that line and it will resize as you move the window that is at the line endpoint (picture here). To complete this, leave the line there but hide it so it remains an active component as far as the measurement goes.
Action shot using a dimension on a line to measure space as we adjust the position of another object.
Sk4D emphasises the need early to take note of how to use the inferences and lock or encourage inferencing. I agree with his priority – a lot of the speed of modeling in SketchUp comes from how well inferencing supports your sloppy mouse movements.


Sheets of stuff that look like tiles on one side and are joined by cauking to give a seamless wall. We’re using them because the bathroom in the rental property is made out of some kind of hard sheeting which has enough give in it that the few tiles stuck to it already keep coming off. The sheeting is also joined with an H-strip which provides a lovely narrow crack just perfect for mould to grow in and spread. As a result, the delightfully finicky refugee tenant with her three kids spends a lot of time scrubbing with bleach, which is not helping the remaining tiles stay on the wall!

From the manufacturer’s website:

Ceramilite is manufactured by applying a series of sophisticated polyester-epoxy synthetic paint coatings to a 3mm tempered, smooth, two-sided hardboard substrate. When installed to the manufactures installation instructions, Ceramilite provides a moisture resistant panelling product suitable for wet areas.
Available in 2432mm x 1213mm, 2432mm x 910mm and 1830 x 910mm* sheets, Ceramilite Designer Tile Panels are specifically designed for use in any vertical high moisture, humidity or heavy public traffic area such as bathroom, laundries, kitchens and commercial areas.

and the bit that really sold us:

No mould or Mildew
Mould will not grow on Ceramilite Designer Tile Panels
as each panel is sealed with a hard, durable, scratch-resistant finish.

Ceramilite’s surface finish runs between the tiles, thus
mildew will not build up in areas you normally have to grout.

No grouting
In a standard shower recess there is 63 metres of grouting to be laid and maintained. In a Ceramilite
shower recess there is none!.

No peeling wallpaper
The Ceramilite 100% moisture proof tile panel will not
peel, fade, or discolour like wallpaper in moist conditions.

Easy to clean
No need for any more scrubbing – a wipe over of Ceramilite with a damp cloth or any non-abrasive liquid bathroom cleaner will remove any soap residues and restore it to pristine condition.