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Van Build Order: What to Install First

The order to build out a camper van: plan the weight, cut roof and window holes, insulate, fit the heater, wire, build walls and furniture, then test a CO alarm.

By Van Build Gear ReviewPublished 2 min readHow we research
A weathered blue pop-top camper van waiting for restoration

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Plan the weight, cut the holes, insulate, install the heater, run the wiring, build walls and furniture, then test everything with a carbon monoxide alarm in place. Holes come first because a 14 inch fan opening or a heater exhaust through the floor is far harder to add once walls and insulation are in.

The order

  1. Plan and weigh. Find the occupants-and-cargo limit on the placard (49 CFR 571.110) and budget the build in the payload calculator.
  2. Cut roof and window holes. MAXXAIR's Deluxe fans fit 14 x 14 inch openings; Dometic lists a 350 mm cutout for the Fan-Tastic 3350.
  3. Floor. Rigid board between battens; DOE lists XPS at R-5.0 per inch.
  4. Heater. Floor holes for exhaust and intake; Webasto's manual requires the exhaust outlet be positioned so fumes cannot enter the vehicle interior.
  5. Insulate walls and roof. See how to insulate a van.
  6. Wire. Runs for the fan, fridge, lights and a Starlink Mini before panels go up.
  7. Walls, bed and kitchen.
  8. Toilet and fridge. Vent the toilet and leave airflow around the fridge.
  9. CO alarm and test. A UL 2034 alarm, per the CPSC, before the first night.
MaxxFan Deluxe 7500KCheck price on Amazon

Why holes first

A fan, a heater exhaust and a toilet vent all pass through the shell. Cutting them into a finished wall means removing insulation and panels.

Gear by step

Heaters: best diesel heaters. Overview: van build guide.

Frequently asked questions

What order should you build a camper van?

Plan weight, cut holes, floor, heater, insulation, wiring, walls and furniture, then toilet, fridge and a CO alarm test.

Should I install the roof fan before insulation?

Yes. Cutting the 14 inch opening first avoids tearing out insulation and ceiling panels later.

When should the diesel heater go in?

Early, before the floor is finished, since its exhaust and air intake pass through the floor.

When should I run wiring in a van?

After insulation and before the wall and ceiling panels go up, so wires stay accessible during the build.

When do I fit the carbon monoxide alarm?

Before the first night with any fuel-burning appliance. The CPSC recommends a UL 2034 alarm.

Sources

  1. 49 CFR 571.110: Tire selection and rims and load carrying capacity information (FMVSS 110), Legal Information Institute (Cornell Law School)
  2. MAXXFAN Deluxe, MAXXAIR
  3. Dometic FanTastic Vent 3350, Dometic
  4. Energy Renovations: Insulation, A Guide for Contractors to Share with Homeowners (PNNL-20972), U.S. Department of Energy
  5. Air Top 2000 STC Installation Manual, Webasto Thermo & Comfort N.A.
  6. Carbon Monoxide Questions and Answers, U.S. Consumer Product Safety Commission

Cover photo: old blue camper van white, CC0 1.0, via rawpixel. Cropped.

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