The most repeated error in sizing a booth is counting the part alone. A chamber that fits the vehicle exactly does not fit the person who has to paint it.
Internal size is therefore fixed from the dimensions of the part to be coated plus the technician working space allowance around it — an item in the calculation rather than an optional safety margin.
Why the effect shows in quality before space
Spraying needs a consistent distance between gun and surface and a consistent angle onto it. A technician wedged between the part and the wall loses one or both, and the result appears as uneven film build rather than as a complaint about a tight chamber. That is an effect measured on the finished surface after the booth has already been installed.
Where the allowance enters the process
| Step | What it covers |
|---|---|
| Site survey | Space available and entry route |
| Fixing internal size | Part dimensions plus the technician’s working space |
| Configuration sign off | Extraction, heating, filtration and doors |
And the booth itself needs space around it
Working space inside the chamber is one item; service space outside it is another. A booth needs space around it and not only its own footprint — to swing the doors open and to reach the air handling unit and filter box at change-out. Both are counted together when reading the space available on site.
Frequently asked questions
How much is added around the part?
The allowance follows the type of work and how the part enters the chamber, and whether it is coated standing or hung. It is therefore fixed at the site survey alongside the internal size rather than by a general rule — what is needed from you is the dimensions of the largest part and how it enters.
Is space measured with doors open or closed?
Working space is measured inside the chamber. Service space is measured with doors open, because opening them is an operating and maintenance requirement. The published main door range runs from 3000×2600 to 14,200×5,000 mm powered.
What if parts vary in size?
The size is fixed on the largest, because widening a built chamber is harder than building it wider at the start. Delivered internal length runs from 3000 to 24,000 mm, so the capacity is there.
Does this apply to stock models?
INTECH models are built on a 6900×4000×2650 mm internal cabin, an automotive size that already accounts for spraying around the vehicle. The calculation above applies to anything beyond that size, built to order.
Related reading
- Service Clearance Around the Booth
- When to Leave the 6900 Size for a Custom Booth
- Extraction Direction in a Custom Booth
What to do next
Send the dimensions of the largest part to be coated, your site area and the supply capacity available, and we will come back with an internal size and a configuration built on it. Talk to a specialist. The published range sits on the paint booth family page.