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How to convert your own campervan

Where to start?

The First thing you should work out when thinking about your own campervan is what van do you want. There are lots of things to consider here starting from what you're after in your van and where you want to take it. 

Van type

Ask yourself these questions........

  1. How many people do I want the van to accommodate?

  2. Do I want to travel off-grid?

  3. How long do I want to spend in the campervan?

  4. Where do I plan to go?

  5. What facilities do I value (bathroom/kitchen)?

  6. Do I need to store large items like bicycles or surfboards?

Look at the examples below of the different sizes that Mercedes Sprinter vans come in to help you decide how large or small you want your vehicle.


Compact van

The smallest of the vans, this vehicle will require some clever engineering to fit basic needs inside. A small bed can be created with some clever adaptations and everything inside needs to be designed with multifunction in mind. 

Double bed

Small bed








Standard van

This van will still fit into a standard size parking space, yet offers more room inside for comfort. A double bed can be created by manipulating a table and benches for multifunctional use, and a cassette toilet can be added into a cupboard and slid out once needed. Also a small kitchenette can be created behind the bulkhead with a burner unit and small sink for convenience. Everything in this space must still be multifunctional like the compact van, but does allow a little more room for comfort. 

Double bed

Small bed




Instead of a double but not as well as.

No but a compact toilet can fit into a multiuse cupboard



Long Wheel-base Van

This van allows you to have all the creature comforts to make your van the ideal home away from home. If you're planning on living in your van either full or part-time, this is the one for you. With enough space for a double bed, kitchen, wet room, dining space and even a convertible single bed for when friends and family visit (and I can assure you, they will), this is the ideal van. However there are some drawbacks. This van requires 2 parking spaces back to back to fit into, and many carparks will still fine you, even if you pay for 2 tickets, as you're not parked within the white lines. Tight turns and small lanes can be tricky to navigate, which around the UK especially are very common. Depending upon the LWB van you purchase, be aware of the weight limits and engine strength as steep roads can also be a problem in this vehicle. I have a Mercedes Sprinter and I have tested her to the limit, on Englands steepest road. She made it, just. Anything greater than a 30% gradient is tough - even in 1st gear. 

Double bed

Single bed







Now design your layout

Use a scale on graph paper to really see how your design will fit together.

This is the stage where I wanted to see exactly how my van would work out based upon the size of van I chose. I settled on the image on the right as I felt this allowed me to have everything I needed inside. I didn't want to have to convert my double bed from a table every time I wanted to use it, so having it as a permanent feature was a must. I also wanted a shower and toilet that was comfortable enough that I'd want to use it, rather than having to stay in campsites and use their facilities. By creating a bench unit and semi-permanent table by the sliding door, I gave myself the option to stay inside with the door open and still be able to see out. This design also showed me where integral components would fit, like the fridge unit and water tanks. 

My design really hasn't changed much since this initial drawing, and it served as a great plan to start my build. The only changes I made were the single bed, which is where I've put my wardrobe for clothes storage and the fridge space which is actually under the bench now and the lower storage is my larder cupboard for food. 


First Fix Plans


AC power plan

This shows the final layout with a plan for where mains power needs to be delivered for both power outlets and electrical appliances that run on AC.


Hot and Cold water plan

This plan shows where the hot and cold water needs to reach, in order to plan where the appliances need to be placed


DC power plan

As well as an AC electricity plan, I also needed a DC plan for appliances that run directly off the batteries and DC power outlets.

Electrical system

Campervan Electrics

There are two different types of electrical systems you need to get your head around if you're going to build your own campervan; AC and DC.


Here are the basic differences:

  • AC systems are like that in your home. Often referred to as 'mains' power, this system works off 220v-240v in Europe and the UK and 120v in the US (hence why if you take your hairdryer over to the US, it'll blow up). Most appliances will run off these voltages which is why you can't just buy any old appliance for your van. Instead you'll need DC. AC power must have a completed circuit with a return to the device creating the power (in this case the inverter - see below).

  • DC systems are what batteries produce. And most leisure/vehicle batteries run off 12v. So anything you buy for your van must also run off 12v otherwise it won't work. The DC power output goes directly to the skin of the van as it's earth, so doesn't need a return circuit.

Now you can see with my plans above, I have both AC and DC circuitry plans. And that's because I still want at times to be able to use things that I've brought from home, like hairdryers or a plug-in electric heater. These items require a tremendous amount of power, so I don't use them all the time, but I have a plan for that......... So in order to get my DC power from the batteries to run my AC appliances, I need a device called an inverter. This effectively gives me mains power like I would have in my house. Now there is a big downside to having an inverter, and this is one I realised once I was on the road and using it. The inverter uses power just to run itself. And even the best, most expensive inverters use a lot of power. They declare around 0.2ah (that's amps per hour) however I've calculated that mine uses closer to 2-5ah. This means that just to have it switched on but not in use, it's using my batteries up. So my advice would be not to use one. Get every appliance you can that will run directly off your batteries at 12v. 

You can still use AC power without an inverter by having an electric hook-up point fitted to your van, so that whenever you use a campsite, you can plug in and use their power. This was an after-thought for me and something I added after 6 months of using my van and realising my needs. I don't use it often, but when I do, it feels like such a luxury!

I've talked a lot about the power from the batteries, but let me now describe how the power gets to the batteries in the first place. I have a solar panel on my roof, which in good sunlight, can provide me with 8ah. I have two leisure batteries which can hold up to 110a each, so I have a total capacity of 220ah in the two batteries. So by that logic, in full sunlight, it would take my solar panel 27 1/2 hours to fully charge my batteries from empty. However it's rarely full sunlight in the UK. And depending upon the time of year, there maybe only 8 hours of indirect, winter sunlight a day. So at times my solar panel isn't quite enough to run all the appliances I have and keep the batteries fully charged. This is where you may need another device and it depends on what type of van you have. A split charger will connect your leisure batteries to the vans internal battery to allow for cross charging. However, most modern vans have what's called a 'smart alternator'. And this is a problem if you want to utilise the engines power when driving to charge up your batteries. The smart alternator works by only using engine power to charge the batteries when it senses that the battery isn't full. As soon as the battery is fully charged, the smart alternator switches itself off to prevent fuel wastage and that's it, no more charging. You might think that this is exactly what you're after, however the part you might not have realised is that the alternator is connected to the vans internal battery and not to your leisure batteries. The vans internal battery is used for starting the engine and not much else, so it's quickly replenished once the engine is working and hence the smart alternator stops charging pretty soon after you start to drive. So if you have a modern van with a smart alternator, a split charger will simply not work for you. Instead you'll need a more expensive DC to DC charger. This charges the leisure batteries directly off the van battery (when the van battery is being charged - to prevent the leisure batteries draining your van battery when not in use). So since the van battery is constantly being used to charge the leisure batteries when they're not fully charged, the smart alternator thinks it still needs charging and will continue to do so until all three of the batteries are full. This means that even if the solar panels aren't giving quite enough power to the batteries, the engine will top them up. 

It's a pretty complicated system so here's the summary:

  • You need enough batteries to power all your appliances.

  • Batteries are rated in amps and each appliance uses so many amps per hour (ah).

  • Solar panels need to provide enough power to charge up your batteries and run your appliances.

  • If your solar panel doesn't provide enough power, you'll need to top it up with engine power.

  • Modern vans require a DC to DC charger, older models should be fine with a split charger.

  • Batteries produce 12v DC power, so if you want to use appliances from home, you'll need an inverter.

Now to give you an idea of how much power you'll actually be using, here's a rough guide. When you charge your mobile device up using a car charger, it normally charges at a rate of either 1 or 2 amps per hour and it normally takes a few hours to charge fully. So a phone or iPad really doesn't use that much power. I have a really good campervan fridge specifically designed to use little power and generally when it's switched on the whole time, it runs for around 5 minutes an hour and uses about 5ah. So if both my fridge was on and I was charging my phone, but I was in direct sunlight with my solar panels producing 8ah, I would still have enough power from the solar panels to charge the battery and run both appliances. But if its winter and a cloudy day so my solar panels are only producing around 2ah, I would be using battery power to run the fridge and the batteries would start to deplete. Most appliances designed for campervans are incredibly low power and many also come with a fail safe that stops the appliance drawing power if the voltage goes below 10v (this is when your battery power is low and prevents the battery from fully discharging which can damage the battery). So power usage won't be that high depending upon your specific needs. 

Here's a list of the appliances I have that use my electricity:

  1. Gas hob (electricity for ignition of the gas) (AC circuit using inverter)

  2. Gas heater (electricity for ignition of the gas and running the fan)

  3. Gas/electric boiler 

  4. Water pump

  5. Fridge

  6. Lighting (AC circuit using inverter)

  7. Wet-room fan

  8. Inverter

  9. Wall sockets for charging (both AC and DC circuits)

  10. Water level indicator

GAs Appliances

Gas system

Gas system

Now's the time to decide what appliances you really need!

I wanted all of the home comforts and to be able to use my van in all seasons, which in the UK means heating. I wanted hot water and a heater for use when not on campsites and using electric hookup. 

Many campervan heating appliances use gas as their main source to heat both water and air, so you'll need a gas safe engineer to provide gas lines from your gas container to each appliance. I have three lines; one to the heater, one to the boiler and one to the gas hob. Each line can be independently disconnected and there's a master shutoff to the whole container which I use when driving to secure the line. Rules in the UK state that the gas container must be able to be outside vented with it's own door. I've positioned mine so that just by opening the sliding door, you can vent it and remove as necessary. You also need to have stickers on the outside of the vehicle stating where the gas is contained for safety by emergency services. I have one large tank that I use normally and one smaller tank for emergency purposes if I run out. Just for perspective however, I have three items running off my tank, the hob gets used at least twice a day for cooking, the heating gets used on average for 30 minutes once a week, and at the water boiler gets used on average for 45 minutes most days. I've used the van for probably 3 months cumulatively and I'm still not even half way through my first tank. So in other words, you really don't use a lot of gas. 


Plumbing plans

Depending upon your personal needs, here's where you decide what plumbing you want.

Just to be clear, I really wanted the van to be comfortable all year round to make sure I'd get full use out of her. Hence why I put in a full wetroom with hot water and proper cassette toilet. Most people do not want that level of luxury, especially as it comes at a cost. Extra appliances mean more battery power needed, more gas needed, and greater cost for each appliance. So don't feel like you need to add these to your conversion. This is just a discussion of what I put into Frida.



Now the cassette toilet doesn't run off the plumbing in any way and is in fact completely removable from the van, so I won't go into that right now. But the wetroom is built in, so that's where I'll start. I have a 105lt fresh water tank inside the van (so it doesn't freeze in the winter), and a 60lt waste tank which sits under the van (but I have it open most of the time, so it's constantly emptying when I drive). The waste tank only has water from the shower and sink, so it's considered grey water and is not harmful. The fresh water tank is filled from an input on the outside of the van and I have a level gauge inside the van so I can see how much is left. A pump takes the water from the fresh water tank directly to the cold system or to the heater. Both taps I have (the one in the shower and the one for the sink in the kitchen) are mixer taps and have an inlet for cold water and hot water, where they are then mixed to give the desired temperature. The mixer tap outlet for the shower then goes to a low water use shower head to reduce how much water actually comes out. The pump creates high pressure, but the shower head fools you into thinking it's even higher pressure, while actually preventing over usage. For perspective, on my own, if I have a shower every day, I have enough water in the tank to last approximately 6 days. I'll generally book a campsite to refill the tank every 4-5 days though, just to be on the safe side. 

With so many different appliances, you need to be aware of varying plumbing sizes. This is where the world hasn't quite caught up with self-build campervans, as there's no system compatibility among the applainces. So for example, my tank has an outlet that's 3/4"BSP, but the pump inlet is 12mm. The mixer tap inlets are 1/2"BSP. So you can see that you'll need plenty of size converters. It's not difficult to find them, but does make the system far more complicated than it needs to be. Also grey water wastes pipes and tanks work on 22mm, so you'll need a different sized pipe for this in comparison to the fresh water inlet that connects to a 25mm pipe. It's worth having a plan of exactly what connects to what and what converter you'll need to make the system work. 

Plumbing appliances I have in my system:

  1. Fresh water tank

  2. Waste water tank

  3. Lockable water inlet for the exterior of the van

  4. Water level indicator

  5. Water pump

  6. Water boiler

  7. Kitchen sink and tap

  8. Wetroom shower mixer unit

  9. Pipe for the internal hot and cold water system

  10. Pipe for the fresh water inlet

  11. Pipe for the waste water outlet

  12. Various fittings to connect the system together

And finally, don't forget that you'll need to drill holes through the floor of the van to get the waste water out of the vehicle. This means careful positioning of the shower waste and sink system waste to allow for pipes to go through the van floor and not hit anything integral under the van. 


Now to decide on your own personal style!

Set up a Pinterest account and look at all the different campervan styles to help you decide how you want your final van to look.

always wanted my van to feel like a home away from home, so I chose a style similar to my apartment. Re-using lots of things I already had lying around, like pallets, scaffold planks and faux plants, I was able to create a cozy and relaxing feeling inside. Believe it or not, the very first thing I bought for my van (even before the van) was door handles. I decided I was finally going to purchase a van to convert and was walking through TK Maxx when I noticed door handles that looked like beach glass. I thought it was a sign as I'd always imagined my van facing the beach on a beautiful warm summers evening - which in the UK just about never happens, so that fantasy hasn't quite been realised yet...... So I purchased the door handles and that was the start of my collection.


The build

This is where the fun/hard work starts

Once you've designed your layout, selected your vehicle, planned out where all the appliances should go and therefore designed your first fix system, you can finally start your build. It's daunting to start with, but you'll soon get into the flow and then you won't want to stop as you know you're so close to your campervan dream life!

The build

Step 1

Clear out any old panelling, flooring and electrical fittings. Carefully check the interior of your van for any rust or damage which can be easily repaired at this stage, but will become almost impossible once you've fitted it out. Next, screw an internal wooden frame into your van (as can be seen in the image above) and this is where you'll attach wooden cladding and any internal furniture that you're building in. At this point you can do the first fix electrics and gas pipelines for the various appliances. Make sure to mark out exactly where the wires and gas lines are, as once the cladding is in place, you won't be able to find the fixings easily.

Step 2

Now is the time to cut out holes for windows, roof vents, gas appliance vents and waste holes through the floor. There are loads of instruction videos on YouTube for cutting through panel vans, but essentially you'll need some tape and a jigsaw with a metal cutting blade. It's not nearly as scary as it sounds, but remember to always measure twice and cut once. Once the holes are cut, you'll need to create wooden frames for the windows and vents as the skin thickness of the panels will not be thick enough to attach these items to alone. Again, you can see mine in the photo above, where the frame is built around each window.

Step 3

Place insulation between the wooden frames that you've screwed in. Remember to fill every hole with insulation so as to keep the van as comfortable as possible. Then nail and glue cladding to the internal frame. This requires a lot of cutting, so set yourself up a work bench with a circular saw for speed! Onto the cladding, you can now build furniture and appliance housing. This is also the point at which I built my wetroom walls and made sure the space was big enough for the toilet as well. Make sure to glue all wooden fixtures, as the constant moving and twisting of the van as you drive will loosen nails overtime and could lead to breakages.

Step 4

Once the main pieces of furniture are in place, paint everything using a primer firstly to hide any wood bleed through, and then with a hardy furniture paint or chalk paint. Inside my wetroom, I used a yacht varnish to fully waterproof the walls. Even though it says clear on the tin, yacht varnish will always come out a slightly yellow colour, so be aware that if you're aiming for a light colour finish, the yellow varnish will show through. For the wetroom floor, I built a shower tray out of thick ply wood and then fibreglassed this to provide essential waterproofing. Finally add shelving and decorative items to give a homely feel and add extra storage for items like books, games and kitchenware.

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