What should I buy first for a van build?

Before you spend anything

The first three things cost almost nothing:

• A scale ticket. Weigh the empty van by axle with full fuel. It tells you how much build you can carry.
• Measurements. Interior length, width at the floor and at shoulder height, height, wheel wells, the curve of the walls, the sliding-door opening. Brochure numbers aren't close enough to build from.
• A use list. How many people, which seasons, how long between hookups, what you want to cook on, what you need to carry. Later choices get checked against it.

What it depends on

• What's decided. A part bought before the layout is a guess. A part bought after is a dimension you can build around.
• Whether it sets other dimensions. The fridge sets galley width and cabinet height. The mattress sets the bed platform. The fan and windows set where the roof and walls get cut. Buy these first.
• When it gets installed. Roof fans and windows go in early, before insulation. A diesel heater's fuel pickup and exhaust are planned early too. Have those parts on hand when the work comes up.
• Lead time. Some fridges, heaters and windows take weeks. Order them early enough not to stall the build.
• Return windows. Buying something months before you install it often means you can't return it if it doesn't fit.

Why batteries and solar wait

The battery bank comes from your daily power use and how you charge. Solar comes from the roof layout and your season. Both come after the load list and the layout. Buying a kit first means building the rest of the van around whatever the kit happened to be.

Worked sample (planning estimates)

Two fridges you might be choosing between: one 21 in wide, one 23.5 in wide (sample numbers). That 2.5 in comes out of the counter next to it or out of the aisle. In a narrow van, aisle is the part you feel. Pick the fridge first and the galley is drawn around a real number.

A sample order for a first build:

1. Scale ticket, measurements, use list. No spending.
2. Layout drawn to scale, with the bed, galley and storage placed.
3. Fridge and mattress chosen. Their dimensions go on the drawing.
4. Roof fan and windows bought, placed on the drawing, ready to cut.
5. Heater chosen if you want one, fuel pickup and exhaust route planned.
6. Load list summed, then battery, charging and solar sized.
7. Insulation and wiring materials, once the electrical plan and wire paths are set.
8. Cabinet materials last, because cabinets wrap around everything above.

Your order may shift. The rule doesn't: things that set dimensions before things that fill them.

When to bring in a professional

Buying parts is yours. Some installs aren't: high-current wiring, heater fuel and exhaust, roof cuts that touch structure, and seat or seat-belt changes. Knowing which parts will need a professional before you buy helps with budget and timing.