man lying on roof of caravan using tools to build it

Building your own caravan…it’s a challenge, and a very rewarding one at that! Surprisingly, it’s never been a better time to try and build one yourself, thanks to clever advancements such as fibreglass and aluminium composite panels that can be cut to exact specifications, taking a lot of work off your hands but still giving you that DIY feel. Let’s look at how to build a caravan from the chassis up, and the best way to go about it. All up, a project like this could cost anywhere between 5-15k depending on the quality of appliances and if you are sourcing recycled materials. Make sure you leave some wiggle room for time and labour as things always go wrong and if this is your first DIY caravan build you'll need at least 6-8 months to build it from scratch. 

Mock Up Your Chassis Design

The chassis is one of the most important parts of your build, being the skeletal backbone of your caravan. You can’t really have a caravan without one! A chassis supports the body of your caravan and things such as suspension, water tanks and stabiliser legs and usually attached to them. During the design process, you’ll need to make sure you meet all of the technical requirements linked to trailers and caravans. A computer program such as AutoCAD can be very helpful during this process, since it gives you clear visuals and helps you to create precise 2D and 3D images for construction. This is particularly useful if you plan on getting professionals to build your chassis for you, since they’ll have a detailed reference when it comes to the build.

Make (Or Source) The Chassis

When it comes to how to build a caravan chassis, you can either do all the welding yourself, or pay for professionals to do it. Unless you’re a welder or a boiler maker (or have a similar trade), it’s probably best to have someone else build the chassis for you. At this point you’ll need to consider chassis parts and accessories such as jockey wheels. There are other options if you don’t want to build a chassis at all. Instead, you can reuse an old caravan chassis, giving you the framework you need when you’re looking at how to build a caravan from scratch. Once your chassis is built or sourced, make sure to move it into a shed or undercover. You’ll be working on your new caravan for a few months, so you’ll want to project it from the elements. 

shell of caravan being built

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Build The Shell

While traditional stick ‘n tin caravans (that is, caravans with timber frames, aluminium cladding and styrene foam insulation) aren’t going away any time soon, they’re bit tougher to build when you compare them to more modern caravans. With fibreglass and aluminium composite panels growing in popularity, your best bet is to find someone who can cut the exterior “shell” of your caravan to exact dimensions so that you can take advantage of a finished product that is lightweight yet durable. You’ll likely need to get some friends to help you fit the panels together, however – depending on the final sizing of your new caravan, some of the panels will be tricky to position. The shell should have cut-outs that take into account other parts of the caravan, including hatches, vents, doors and windows. Once everything is assembled, be sure to waterproof with the correct sealant. Commonly used types include butyl mastic, polyurethane and silicone. Seal all the way around the external edges and any roof seals – if it looks like there’s even the slightest gap, fill it in.

Add Power And Plumbing

Before you get carried away with the wood work, map out with tape on the floor where you want the main appliances to be, such as your fridge, batteries, sink or washing machine. These will be key items to place in the correct area and will be very difficult to move later so be sure they meet legal standards if they are gas powered. When you’re looking in to how to build a caravan from scratch, mastering plumbing and electrical can be a challenge, and government guidelines insist that they be carried out by a licensed professional. It might add a bit extra to your budget, but you’ll be much safer for it. For electricity, you’ll generally need an extension lead to supply 240V to your caravan, a power inlet, earth connections, a circuit breaker, switches and power points. Wiring location is also important. Plumbing is a bit different and generally can be a DIY project. When designing your caravan’s internal plumbing system, you’ll want to consider a portable tank with a tap, manual and remote water fillers, an electrical 12v water pump, filter and accumulator, and adding mains to pressure, grey water hose, fresh water hose and black waste hose and hot water.

paint roller resting in white paint

Paint The Exterior

If you opted for a composite caravan, you probably won’t need to add paint to the exterior unless you want to add a splash of colour. For a more traditional caravan build, paint will protect the cladding from rust and wear. If you’re looking for what paint to use on aluminium caravan, a good option is a high-quality, oil-based undercoat applied with a paint roller. Be sure not to do this on too hot a day, as it can affect the way in which the paint dries. You can also look into spraying the paint on, which will give you a much more even finish.

man standing inside half built caravan

This is where you get to make your dreams a reality. You can either purchase pre-made cabinetry from somewhere like Ikea, or build the entire interior yourself, from overhead storage to kitchen drawers to bunk beds for the kids. There’s really no limit to what you can do, save for the size of your caravan. The interior generally needs to be done before electrical wiring and plumbing are completed, and the layout should also take weight distribution into account. For example, you don’t want too many heavy appliances in the kitchen without balancing things out in, say the dining area. Befire adding any additional roofing, make sure you install an exhaust vent or airconditioner depnding on your needs. If you plan on cooking inside you will at bare minimum need one vent over the two burner. 

Looking for some caravan DIY reno inspiration? We’ve got you covered in our dedicated blog post. 

So, do you think you’re up to the challenge? Learning how to build a caravan can be a little overwhelming at times…but your labour of love will definitely pay off! If you are keen we have pretty much everything you'll need to to get right into here at Outback Equipment in the Caravan & RV category!