Van Conversion Costs: The Lines Almost Everyone Forgets
August 4, 2026
Van build budgets rarely fail on the mattress or the fridge. Those get costed carefully, because they are the fun part. They fail on the lines nobody photographs.
Fixings. Cable. Tools. Insurance. Adhesive. Individually forgettable, collectively often €1,000–1,500 on an ordinary self-build — enough to stop a project at the point where the walls are open and the money is gone.
The free van build cost planner lists 60 components across ten systems, with the forgettable ones already on the list, so the total you see at the start is closer to the total you pay.
The five most commonly missed lines
1. Fixings and adhesive — €200–300. Screws, rivnuts, self-tappers, sealant, construction adhesive, cable ties. Bought in a dozen separate trips, never in one visible sum.
2. Cable and connectors — €150–250. Thick DC cable is expensive per metre, and a 12V system needs more of it than people expect, plus lugs, a proper crimper, heat shrink and fuses. This is not a place to economise; undersized cable is a fire.
3. Tools bought for this build — €300–500. A jigsaw, hole saws for the fan and vents, a multimeter, a decent crimper. They stay yours afterwards, which is why people leave them out of the budget — and why the budget is then wrong.
4. Insurance and paperwork — €150–350. Telling your insurer the van is now a conversion is not optional; cover that does not reflect the vehicle is cover that may not pay out. Depending on where you are, reclassification or a habitation check adds more.
5. Vapour barrier and sealing — €70–120. Cheap, dull, and the difference between a dry van and mould behind the cladding in eighteen months.
What a build actually splits into
For a mid-range DIY conversion, the rough shape of spending looks like this:
| System | Typical share |
|---|---|
| Electrics | 20–28% |
| Furniture and interior | 18–24% |
| Heat, cooking and fridge | 14–18% |
| Insulation and structure | 10–15% |
| Water and plumbing | 8–12% |
| Windows and ventilation | 6–9% |
| Outside, security, paperwork, tools | 10–15% |
If electrics and insulation are not among your three biggest lines, it is worth asking why. They are the two that are miserable and expensive to redo once the walls are closed, and the two people most often economise on because neither is visible in a finished photo.
Add 20% contingency, and mean it
Twenty percent is not pessimism. It is the observation that something is always rotten behind a panel, a part is always the wrong size, and the tool you need for one awkward screw costs forty euros on a Sunday.
Builds that come in on budget are almost always builds that planned for this. Builds that “went 20% over” usually went exactly to plan and simply had no line for reality.
What to cut when the number is too high
Not everything is equally postponable. The useful distinction is what you can add later without opening a wall again:
Safe to defer — awning, roof rack, reversing camera, alarm or tracker, inverter, indoor shower, water heater, second window, table and extra seating. All of these bolt on afterwards.
Do not defer — insulation, vapour barrier, wiring runs, gas locker and vents, rust treatment, CO and gas alarm. These are buried, structural, or the difference between a safe van and a dangerous one.
The cheapest line in the whole planner is the carbon monoxide and gas alarm at around €45. It is the only one marked as the one that matters most.
Buy once, cry once — where that is true and where it is not
The phrase is repeated so often it has stopped meaning anything. In practice it holds for a small number of items:
- Mattress. You sleep on it every night. A bad one ends trips early.
- Leisure battery. LiFePO4 costs more up front and outlasts several lead-acid replacements.
- Fridge. A compressor fridge that works in 35°C is a different product from a cool box.
- Diesel heater. The cheap ones are genuinely cheap for a reason, and this one runs while you sleep.
For cladding, handles, worktop and most of the interior, the expensive version mainly looks nicer. Spend the difference on insulation.
Frequently asked questions
How much does a van conversion cost? For a DIY build in 2026, roughly €8,000–€20,000 for the conversion alone on a medium panel van, excluding the vehicle. Professional conversions commonly start around €35,000 and rise steeply. The range is wide because heating, electrics and whether you fit a shower move the total more than anything else.
How much of that is electrics? Usually a fifth to a quarter of the build. A 100Ah lithium battery, solar, MPPT controller, DC-DC charger, fusing, cable and a shunt reach €1,300–1,800 quickly, before lighting or an inverter.
Do I need an inverter? Often not. Most van appliances run on 12V, and an inverter adds cost, heat and standby drain. Add one if you specifically need mains — a laptop charger with a 12V option does not count.
Is the van build cost planner free? Yes. No account, no email, nothing uploaded. It saves in your own browser.
Are the prices in the planner accurate for my country? They are mid-range starting points, not quotes. Every line is editable — overwrite them as real prices come in, and the totals follow.
Can I add components that are not on the list? Yes, in any section, and they save with everything else.
Do I have to tell my insurer about a conversion? Yes. Rules vary by country, but insuring a van as an unconverted panel van when it is a camper risks a claim being refused. This is a paperwork line, not an optional upgrade.
Where is my build data stored? In your browser on that device. Export the backup before clearing browser data or switching computers.
After the build
Once it is finished the tracking changes shape entirely — fuel, tanks, maintenance intervals, where you slept and what it cost. That is VanNest, a one-time purchase with no subscription. There is also a free trip budget calculator if you are costing the travelling rather than the building.
Try it now: Van Build Cost Planner →