What a van conversion actually costs

The honest answer first

A UK self-build campervan conversion, materials only, lands in one of three brackets. The same three brackets the component library on this site uses for its Budget, Mid and Premium tiers.

• Budget, roughly £3,000 to £6,000. AGM leisure battery, basic solar, a diesel or gas heater, ply furniture you build yourself, a portable toilet. A genuine van you can sleep and cook in.
• Mid, roughly £8,000 to £15,000. Lithium battery, Victron charging, more solar, a proper compressor fridge, a cassette or composting toilet, lighter furniture, maybe a roof vent and a small water system.
• Premium, roughly £18,000 to £30,000 plus. Large lithium bank or an all-in-one power system, an inverter-charger, a diesel heater and possibly roof air-con, an M1 crash-tested seat-bed, a full bathroom, quality fixtures.

The van itself is on top of those numbers. A clean panel van is another £8,000 to £25,000 depending on size and age.

These are planning estimates, not quotes. The only way to get a number that is actually yours is to list what you will buy. That is what the planner does.

What actually drives the bill

Three systems swallow most of the money.

Power

The electrical system is the single biggest variable. A budget AGM setup (a 100Ah battery, a small solar controller, a basic inverter) is around £350 in parts. Step up to lithium with Victron charging and you are at £600 to £1,000. Go to a large lithium bank with an inverter-charger, or an all-in-one unit like a Clayton Power LPSII, and the power system alone is £1,500 to £3,800.

Induction cooking multiplies this. Cooking on electricity means you need the battery to match, and that battery is heavy and expensive.

Furniture and the bed

Ply, framing, a bed platform and a kitchen carcass are cheap in materials and expensive in time. A flat-pack or DIY build is £150 to £400 in ply and hardware. A crash-tested seat-bed with belts is £800 to £2,500 and it is the only safe way to carry passengers in the back.

Heating and cooling

A diesel heater is the efficient choice: budget units from £60, an Autoterm or Webasto from £500 to £1,150, and they run for pennies. Gas heating is cheaper to buy but the bottles are heavy and you need Gas Safe sign-off. Roof air-con is a premium item at £1,200 to £2,200 and it sits high on the roof, which changes how the van drives.

A budget build, line by line

Grounded in the Budget tier of the component library.

System	Rough cost
Power core (AGM battery, basic controller, inverter)	£350 to £470
Solar (one or two budget panels)	£25 to £70
Heating (budget diesel heater)	£60 to £120
Water (manual pump, basic tank)	£20 to £150
Insulation	£40 to £60
Walls and floor (ply)	£40 to £120
Furniture (DIY ply)	£40 to £150
Cooking (single-burner)	£45
Refrigeration (thermoelectric or cool box)	£40 to £350
Safety (smoke, gas, first aid)	£0 to £45

Add tools, sealant, cable, fixings and a float for the boring bits. A realistic budget self-build, including a few mid-tier upgrades where it matters (a decent heater, a real compressor fridge), lands around £4,000 to £6,000 in materials.

A mid build, line by line

This is where most self-builds end up.

System	Rough cost
Power core (100Ah lithium, Victron solar and DC-DC)	£600 to £1,000
Solar (two to four panels, mid controller)	£100 to £250
Heating (Autoterm Air 2D or similar)	£500 to £900
Water (pump, filter, 50 to 80L tank)	£100 to £330
Insulation (closed cell + vapour control)	£90 to £200
Walls and floor	£90 to £220
Furniture (lighter, some bought units)	£200 to £610
Cooking (two-burner hob)	£60 to £250
Refrigeration (12V compressor, 40 to 60L)	£400 to £700
Bathroom (cassette or composting toilet)	£90 to £180

A mid build, done well, is £8,000 to £13,000 in materials. The jump from budget to mid is mostly power and refrigeration. Lithium and a compressor fridge are the two upgrades people never regret.

A premium build, line by line

System	Rough cost
Power core (200Ah plus lithium, inverter-charger, or all-in-one)	£1,500 to £3,800
Solar (high output rigid or large flexible array)	£250 plus
Heating (Webasto or Autoterm) and roof air-con	£1,200 to £2,200
Water (full system, hot water, pump, large tank)	£400 to £900
Insulation (premium, sound deadened)	£110 plus
Furniture and fit-out	£800 to £2,500
Cooking (induction or quality gas hob)	£160 to £600
Refrigeration (large 12V compressor)	£500 to £950
Bathroom (full wet room or premium composting)	£400 to £950
Safety and compliance	£120 to £400

A premium build easily runs £18,000 to £30,000 in materials. At this level the cost is driven by big lithium, an all-in-one power system, crash-tested seating, and a real bathroom.

The costs people forget

• Tools and consumables. Sealant, screws, cable glands, heat shrink, offcuts. Keep a few hundred pounds aside.
• Long-lead parts ordered late. Windows, RIB beds and roof racks take four to six weeks. Rushing costs more.
• Sign-off. Gas work needs a Gas Safe engineer. 230V work needs a qualified spark. Budget £200 to £600 for certifications, or more if you need remedial work.
• A payload uprate. If you build heavy, re-plating the van can cost £300 to £1,500 and it is the only proper fix.
• Insurance and DVLA. Re-classifying the van changes insurance. Factor it in before you cut the first panel.

Where to spend, where to save

Spend on the things you touch every day: the bed, the fridge, the heater, the battery. Save on cosmetics. Vinyl and lighting are cheap to upgrade later; a bad battery or an unsafe seat are not.

The most expensive van is the one you build twice because you guessed the layout. Plan it, weigh it, and price it line by line before you order anything.

These figures are planning estimates drawn from the component library on this site. Confirm prices against real products, and run the planner for a number sized to your van and your answers.

Figures in this guide are planning estimates. Confirm weights and prices against real products, and have gas and electrical habitation work signed off by a qualified person.