A free alternative to SketchUp for anything made of pipes
What a general modeller is good at
This is not a page about a bad program. A modeller does things a parts builder never will, and if those are what you need, none of the rest matters.
- Any geometry at all: a room, a roof, a plot, a worktop, a bracket — pipes are one shape among many.
- Free-form design, where the shape is being invented rather than assembled out of what is on sale.
- Presentation: materials, light, a picture a client will actually look at.
- Mixed materials in one model — timber, sheet metal and glass alongside the tubes.
- A large library of ready models and plugins, some of which do produce cut lists.
SketchUp is a trademark of Trimble Inc.; we are not affiliated with Trimble. Its free version runs in a browser and is intended for personal projects, and the desktop editions are paid — check the current terms on the vendor's site before using any of it commercially.
Five questions a pipe project runs into
These are the questions that decide whether the thing gets built, and they arrive in the same order every time. What separates the two columns is not the quality of the software — it is whether there is a parts catalogue underneath it.
| The question | In a general 3D modeller | In a builder over a catalogue |
|---|---|---|
| Will these two ends actually join? | Nothing asks: two cylinders overlap and the model looks fine | Ends that do not mate refuse to connect — thread type, direction and diameter are checked as you build |
| What do I buy? | You count it off the model by eye and name the parts yourself | The list comes out of the layout: names, sizes, quantities |
| Does this size even exist? | Any diameter you type exists, because you typed it | Only sizes that are actually manufactured — the catalogue is the limit |
| I have changed one diameter | Every neighbouring shape is edited by hand | The neighbours and the list follow the change |
| How do I explain this at the counter? | A render, and a conversation about what the tube is | A parts list written in the names the shop uses |
Two jobs that look alike
People arrive at a modeller with two quite different projects, and the swap is worth far more for one of them than the other.
The first is plumbing and heating: an inlet node, a boiler, a manifold, a bathroom. Here the modeller is the wrong shape of tool from the start — the whole difficulty sits in the fittings, threads and sizes, and none of that exists in a modeller.
The second is a structure made of pipe: shelving, a greenhouse frame, a table, a rack. Here the modeller is a reasonable choice and the reason to switch is narrower — the frame goes together out of standard parts, so what you want at the end is the shopping list rather than the render.
What we do not replace
We do not do free-form modelling, materials outside the catalogue, rendering, or importing your existing model — there is no way to bring a model in, and pretending otherwise would waste your afternoon.
What we give instead is narrow and finished: a thing built out of parts that exist, joints checked as you make them, and a list you can hand over at a counter. If the project is mostly pipe, that is nearly all of the work. If the pipes are a detail inside something larger, stay in the modeller and use this for the pipe part.
Common questions
Is SketchUp free?
There is a free version that runs in a browser and is meant for personal projects; the desktop editions are paid. The terms change from time to time, so check them on the vendor's site before any commercial use.
Can I design plumbing in SketchUp?
You can draw it, and people do. What you do not get is the part that causes the trouble: nothing tells you that a thread does not match, that a size is not made, or what the finished run will cost to buy.
What is the quickest way to plan a structure made of pipe?
Assemble it out of parts that exist rather than modelling the shape first. A frame of standard tubes and fittings has very few real degrees of freedom, and starting from the parts removes the step where a joint turns out to be unbuyable.
Do I get a cut list?
You get a parts list from the layout — names, sizes and quantities. For pipe lengths remember that a plain end disappears into the fitting: how much to subtract is in the welding tool, and it is the number that most often ruins a first attempt.
Can I import my SketchUp model?
No. There is no model import in any format: a layout here is assembled from catalogue parts, and a mesh carries none of what the catalogue needs to know. Rebuilding a pipe frame from scratch usually takes minutes.