The van is the foundation of your entire build. Choosing the right one sets the tone for the whole project, from budget to layout. The three biggest factors to weigh are size, reliability, and ongoing costs like fuel.

Let's start with size. Vans generally fall into three categories. Smaller cargo vans, like the Ford Transit Connect or Ram ProMaster City, are nimble and fuel-efficient. They're perfect for weekend trips or solo travelers who don't need a lot of amenities. They drive like a car and can fit in any parking spot.

The most popular choices are full-size cargo vans: the Ford Transit, Ram ProMaster, and Mercedes-Benz Sprinter. These offer enough room for a permanent bed, a small kitchen, and storage. High-roof models even let most people stand up straight inside, which is a huge quality-of-life improvement.

Finally, there are extra-large options like extended-wheelbase Sprinters or even box trucks. These are less vehicles and more tiny homes on wheels. You'll have plenty of space, but they can be challenging to drive, park, and insure.

Reliability is key. Breaking down is never fun, but it's especially stressful when your home is on the back of a tow truck. The popular models are popular for a reason; they generally have strong track records and parts are easy to find. When considering any van, look into its specific engine and transmission history. Some years are better than others.

Fuel efficiency is your biggest recurring cost. A larger van will naturally use more fuel. Diesel engines often get better mileage but can be more expensive to maintain. Do the math to see what fits your long-term travel budget.

The next big decision is whether to buy a new van or a used one. A new van offers peace of mind. It comes with a warranty, has zero miles, and you know its entire history. You won't have to worry about surprise repairs right away. The downside is the cost. New vans are expensive and depreciate the moment you drive them off the lot.

A used van can save you thousands of dollars upfront. You avoid the initial steep depreciation, and you might feel less precious about drilling holes in it during the build. However, you inherit its history, for better or worse. It could have hidden mechanical problems or rust that will cost you time and money down the road.

If you go the used route, a thorough inspection is non-negotiable. You can either pay a trusted mechanic to do a pre-purchase inspection or learn to spot the major red flags yourself.

First, check the body for rust. Look underneath the van, inside the wheel wells, along the roof gutters, and around the windshield. Surface rust can often be treated, but deep, structural rust in the frame is a deal-breaker. Also look for signs of past accidents, like mismatched paint colors or large, uneven gaps between body panels.

Next, inspect the engine. Check the oil dipstick; the oil shouldn't look milky or have metal flecks in it. Look for any visible fluid leaks on the engine block or on the ground beneath the van. When you start it, listen for any knocking or ticking sounds.

Always take it for a test drive. Drive it on local roads and on the highway to see how it handles at different speeds. The transmission should shift smoothly without any clunking or hesitation. Test the brakes to make sure they feel firm and don't make any grinding noises.

Finally, ask for the vehicle's history report and any service records the owner has. A van with a documented history of regular oil changes and maintenance is always a safer bet.