In my opinion, this part of building a van tends to be much overlooked. There are a few main concerns here, and honestly, this is one area where you really need to think things through before you get too far into your build.
Let's say that you bought an RV, and called your insurance company to add it to your policy. This tends to be pretty cut and dry. It has a pretty well defined value, they consider the liability and the replacement cost, and charge you accordingly. To summarize, if you get in an accident, you call them, and if the RV is totaled, they (hopefully, assuming you had comprehensive coverage) pay you the replacement value.
What many people don't realize until after they get a van is that this isn't how most DIY camper van insurance works at all. Many insurance companies won't insure DIY camper vans at all if they know that they are campers. If they don't know they are campers, they may insure them as normal vehicles, but the policy won't cover the value of the build as a camper at all - just the value of the vehicle itself.
Someone I know had a high quality, well built homemade camper van that they'd lived in for about 6 months, stored for a while, and then wanted to sell. They had it parked on the street in front of their house while listed for sale for about $50,000. Before it was sold, it was rear ended by a hit and run driver.
The vehicle was insured, but not as a camper - best case scenario their insurance company would pay out the value of the vehicle itself, which was probably $20,000 at most. All the solar panels, battery system, custom cabinetry, appliances, etc. - none of that was covered.
They were out $30,000+ in build costs.
In another worst-case scenario, let's say that you build out your dream camper van, and get into an accident where you're at fault. You had insurance, but as a work van, not as a camper. When your insurance company investigates, they find out that you had built out a camper, and estimate that the weight of the camper build, water, people, and gear exceeded the weight capacity of the vehicle (GVWR), and they argue that this was what contributed to you not being able to stop in time and rear-ending another vehicle.
Now you're in a really bad situation:
This isn't a hypothetical - insurance companies absolutely do investigate claims, and they will look for reasons to deny coverage, especially on large claims.
Your van catches fire (maybe from an electrical issue, maybe from the diesel heater, who knows). The van and everything in it is destroyed. Your regular auto insurance covers the Kelly Blue Book value of the base van - let's say $25,000.
But you had $15,000 in solar and batteries, $5,000 in the build-out, $3,000 in appliances, plus all your camping gear, laptop, etc. None of that is covered because you were insured as a cargo van, not as a camper.
Some of this varies state by state - please treat this as a starting point and verify the options in your specific location.
There are a few insurance providers that specifically insure DIY camper vans and understand what they are. These companies will actually cover the value of your build, not just the base vehicle.
The key with these: you'll need to provide documentation of your build (photos, receipts, maybe even an appraisal) to establish the value. They'll then give you an "agreed value" or "stated value" policy where both you and the insurer agree upfront what the van is worth.
Expect to pay more than basic auto insurance - these policies typically cost $1000-2000+ per year depending on the value of your build and your coverage levels.
Another potential option is to register your van build as an RV. The requirements to do so can vary significantly by state. In Colorado, where I live, if you meet certain criteria, then you can get your build legally titled as an RV, and purchase RV insurance. This may be your best option if this is possible - you typically pay similar or even reduced rates compared to regular auto insurance, and you get proper coverage for the build.
Most states require some combination of:
Some states also require: toilet, 120V electrical system, or refrigeration
Many people do just insure their van as a regular vehicle and hope for the best. This is certainly the easiest and cheapest option upfront, but you need to understand the risks:
Some regular insurance companies will add a stated value endorsement to your auto policy if you provide documentation. This isn't common, but it's worth asking your current insurer about. You'd provide photos and receipts showing your build costs, and they'd agree to pay out that amount in case of total loss, rather than just the base vehicle value.
This is hit-or-miss - many insurers won't do this, but it doesn't hurt to ask.
Regardless of which insurance route you go, here's what I'd recommend:
If you're building anything more than a basic sleeping platform, you really need to get proper insurance that covers the build. Yes, it's more expensive and more complicated than just insuring it as a cargo van, but the financial risk of not doing so is significant.
Start by checking if you can register your van as an RV in your state - this is often the cleanest solution. If not, get quotes from specialized RV insurers like Roamly.
The peace of mind of knowing that if something happens, you'll actually be made whole, is worth the extra cost.
And whatever you do, don't exceed your GVWR.
This isn't just an insurance issue - it's a safety issue. If you're over weight and get in an accident, you could be personally liable for everything, and your insurance might deny coverage entirely. Weigh your van and make sure you're legal.
This is one of those areas where cutting corners or hoping for the best can really come back to haunt you. Do it right from the start.