How to Build Your Own DIY Modular Campervan in the UK (Step-by-Step Guide)

Building your own DIY modular campervan is one of the most rewarding ways to create a fully customised travel experience. Whether you’re planning weekend adventures or long-term van life, a modular campervan gives you flexibility, efficiency, and cost savings. Unlike fixed conversions, modular designs allow you to reconfigure your layout, remove furniture when not needed, and upgrade components over time.

In this detailed guide, we’ll cover everything you need to know about converting a van into a modular camper in the UK, including legal considerations, choosing the right van, insulation, electrical setup, furniture, and practical tips for budget-friendly builds.

How Modularity Facilitates Multi-Use: A Work Van by Week, Camper by Weekend

One of the biggest advantages of a modular campervan is its ability to serve multiple purposes. Instead of committing your van solely to camping, a modular system allows you to switch between work and leisure modes effortlessly.

For example, during the working week, your van can function as a builder’s van, a delivery vehicle, or a mobile workshop. Then, come the weekend, you simply slot in your pre-built modular camping setup, transforming it into a comfortable camper for adventure.

Modular conversions are ideal for people who need their van for work but also want to enjoy weekend trips without a permanent setup.

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How a Modular System Enables Multi-Use

1. Quick Installation & Removal – Modular units can be secured with quick-release fasteners, allowing them to be removed in minutes.
2. Stackable Storage Boxes – Heavy-duty storage boxes can serve as tool compartments during the week and camping cupboards on weekends.
3. Foldable or Slide-Out Furniture – Fold-down beds or seating can be stored away during the workweek.
4. Kitchen Pods & Removable Appliances – A detachable kitchen unit means your van remains clear when not in use for camping.
5. Track-Mounted Systems – Some builders install aluminium L-track rails to secure both work tools and camper components without drilling multiple holes.

Example: A Builder’s Modular Camper Setup

🛠 Monday – Friday:

• Van is empty except for tool storage racks and work materials.
• A fold-up workbench is attached inside.
• Floor space remains open for cargo or heavy items.

🏕 Friday Night – Sunday:

• Tool racks are removed, and modular bed/storage units are slotted in.
• A removable kitchen pod is secured in place.
• A modular battery pack and solar panel system provide off-grid power.

By using a modular system, you don’t need two separate vehicles – just one van that adapts to your needs on demand.

1. Choosing the Right Van for Your Modular Conversion

Before you start your build, you need to select a van that meets your needs. Consider factors such as size, budget, fuel efficiency, reliability, and ease of conversion.

Best Vans for Modular Conversions in the UK

Van Model	Pros	Cons
Ford Transit (LWB & MWB)	Affordable, widely available, reliable	Some older models have rust issues
Mercedes Sprinter	High build quality, durable, good resale value	Expensive, costly repairs
VW Crafter	Spacious, efficient, good for full-time van life	More expensive than similar-sized vans
Renault Master	Budget-friendly, decent headroom, easy to work on	Lower resale value
Peugeot Boxer / Citroën Relay	Boxy shape (ideal for modular builds), fuel-efficient	Interior trim can feel basic
Vauxhall Movano	Good for DIY, spacious, affordable	Not as common, harder to find parts

Things to Consider Before Buying

✅ Size – Short wheelbase (SWB) for city driving, long wheelbase (LWB) for more space
✅ Mileage & Condition – Look for service history, minimal rust, and low mileage
✅ Height – High-roof vans are better for standing space
✅ Insurance & Road Tax – Campervan classification can lower insurance premiums

💡 Tip: Before committing to a purchase, check van dimensions against your planned layout!

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2. Planning Your Modular Campervan Layout

Unlike fixed conversions, a modular campervan allows you to change your setup based on your needs. You can remove sections, store furniture when not in use, or rearrange your living space.

Popular Modular Layout Styles

🔹 Fixed Bed Layout – Ideal for full-time van life, but takes up permanent space
🔹 Convertible Bed/Dining Area – Best for small vans; bed converts into a seating area
🔹 Pull-Out or Folding Bed – Saves space; works well in SWB vans
🔹 Sliding Kitchen Module – Allows outdoor cooking when the weather is nice
🔹 Stackable Storage Units – Can be rearranged depending on the trip

💡 Tip: Use 3D design software (e.g., SketchUp) to visualise your layout before building!

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3. Modular Electrical, Water & Gas Systems: Simplifying Setup & Flexibility

Many people worry that electrical, water, and gas systems are too complex for a modular camper build. However, with the right quick-connect systems and portable components, it’s easier than ever to make them semi-fixed or fully removable.

How to Build a Modular Electrical System

Instead of permanently wiring everything into the van, you can create a plug-and-play electrical system using quick-connect fittings and portable power stations.

🔌 Option 1: Semi-Fixed Electrical Setup

• A leisure battery is installed securely under the seat or in a removable battery box.
• Solar panels are roof-mounted, feeding into a charge controller connected to the battery.
• USB ports, lights, and 12V sockets remain wired in place, but the battery can be disconnected if needed.

🔌 Option 2: Fully Removable Electrical Setup

• Use a portable power station (e.g., EcoFlow, Jackery, or Bluetti) instead of a fixed leisure battery.
• Plug-in solar panels that fold away when not in use.
• 12V appliances (fridges, lights) connect via Anderson plugs, allowing easy disconnection when packing up.

💡 Tip: If you need extra power during the workweek, a dual-purpose inverter allows you to run tools from the same battery system used for camping.

How to Build a Modular Water System

A fixed water system is great for full-time van lifers, but a modular water system makes it easier to remove and store during winter or when the van is being used for other purposes.

🚰 Option 1: Semi-Fixed Water Setup

• A 20-30L fresh water tank is mounted inside the van.
• A 12V electric water pump is wired into the van but uses quick-connect plumbing fittings.
• A removable grey water tank is placed under the sink for easy disposal.

🚰 Option 2: Fully Removable Water Setup

• Use portable water jugs with a manual foot pump for the sink.
• Attach a clip-on outdoor shower system that can be stored when not in use.
• A collapsible sink and basin allow easy washing without built-in plumbing.

💡 Tip: Using quick-release hose fittings makes it easy to remove or swap water tanks.

How to Build a Modular Gas System

Instead of installing a permanent gas hookup, many DIY van builders in the UK use a modular gas setup for safety and convenience.

🔥 Option 1: Semi-Fixed Gas Setup

• A secured LPG gas bottle with a regulator and gas hose.
• A fixed 2-burner gas hob, but with quick-disconnect fittings so the gas bottle can be removed.

🔥 Option 2: Fully Removable Gas Setup

• Use a portable camping stove with disposable butane canisters.
• Store the stove in a dedicated pull-out kitchen drawer for easy access.

💡 Tip: A quick-connect gas system lets you attach or remove the gas bottle without tools, making it safer and easier to swap.

4. Installing the Electrical System

A reliable electrical system powers your lights, fridge, charging ports, and appliances.

Essential Electrical Components

✅ Leisure Battery (100Ah – 200Ah) – Powers everything when off-grid
✅ Solar Panels (100W – 400W) – Keeps your battery charged sustainably
✅ 12V Split Charge Relay – Charges the battery while driving
✅ Fuse Box & Wiring – Ensures electrical safety
✅ LED Lighting – Energy-efficient and low heat output

Basic Wiring Diagram

(for more on this read my Beginners Guide to Camper Electrics and my A Guide to Electrical Cable Sizing)

🔌 Solar Panels → Charge Controller → Leisure Battery
🔌 Alternator (via Split Charge Relay) → Leisure Battery
🔌 Battery → Fuse Box → Lights, USB Ports, Fridge, Water Pump

💡 Tip: If unsure, consult an auto electrician to check your setup before connecting!

5. Plumbing & Water Systems

A simple modular water system allows for easy removal and winter storage.

Basic Setup for Campervan Water System

🚰 Fresh Water Tank (10-30L) → Sink with Pump → Grey Water Tank (Removable)

Optional Add-ons:
✅ 12V Water Pump – For pressurised water
✅ Outdoor Shower Setup – Heated via solar shower bag
✅ Portable Toilet (Thetford / Dometic) – Ideal for stealth camping

💡 Tip: Keep the system modular by using quick-release fittings for easy removal!

6. Building Modular Furniture & Storage

The key to a modular campervan is removable and multi-functional furniture.

Modular Furniture Ideas

🔹 Sliding Kitchen Unit – Can be used indoors or outdoors
🔹 Fold-Down Table & Bench Seats – Saves space when not in use
🔹 Stackable Storage Boxes – Customisable and can double as seating
🔹 Murphy-Style Fold-Up Bed – Folds away when not needed

Best Materials for DIY Modular Campervans

Material	Pros	Cons
Plywood (9-12mm Marine Ply)	Durable, lightweight	Can be pricey
Aluminium Framing	Lightweight, rust-proof	Requires specialist tools
MDF (for non-structural parts)	Cheap, easy to cut	Not water-resistant

💡 Tip: Use T-nuts and wing bolts so furniture can be disassembled easily!

7. Legal Considerations & Insurance in the U

To register your campervan with the DVLA, it must meet specific requirements.

DVLA Campervan Classification Requirements

✅ Fixed Bed or Seating Area
✅ Cooking Facilities
✅ Storage Space
✅ Windows & Ventilation

🚐 Insurance – Specialist campervan insurance providers include Adrian Flux, Just Kampers, and Comfort Insurance.

💡 Tip: Check if your van qualifies for “motor caravan” status to get lower road tax!

Why a Modular System Makes Life Easier

1. Simplifies installation – No need for professional wiring or plumbing.
2. Easier maintenance – Components can be removed and repaired individually.
3. Flexibility – Switch between a camper setup and an empty cargo van in minutes.
4. Better resale value – A van without fixed installations can be sold to a broader market.

By using clever quick-connect fittings and portable power sources, even complex systems like electrics, water, and gas can be designed in a way that’s easy to remove, upgrade, or repositio

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1. Quick-Connect Gas Fittings:

• LPG Shop: Specializes in quick-release gas connectors ideal for campervans and motorhomes. Their range includes external quick-release gas points for BBQs and high-pressure quick-release connectors. ​lpgshop.co.uk
• Gas Equipment Direct: Offers a variety of propane gas fittings, including quick-release couplings suitable for 8mm hoses, making them ideal for modular gas systems in campervans. ​Gas Equipment Direct+1lpgshop.co.uk+1
• I Gas Direct: Provides a comprehensive selection of LPG fittings, from copper compression fittings to gas hose fittings, suitable for creating flexible gas systems in campervans. ​igasdirect.co.uk+1Gas Equipment Direct+1

2. Removable Water Tanks and Fittings:

• Tanks Direct: Supplies a range of water tank fittings, including outlets, couplers, and tank connectors, essential for setting up modular water systems in campervans. ​directwatertanks.co.uk
• Direct Water Tanks: Offers IBC fittings and tank-to-tank connectors, which can be utilized to create adaptable water storage solutions in your campervan. ​directwatertanks.co.uk
• Northern Tank Store: Provides various water tank fittings, such as hose clamps and valves, aiding in the customization of your campervan’s water system. ​northerntankstore.co.uk

3. Portable Power Stations:

• EcoFlow: Known for their range of portable power stations, EcoFlow products are suitable for campervan setups, offering reliable off-grid power solutions.​
• Jackery: Offers portable power stations and solar generators that are popular among campervan enthusiasts for their ease of use and reliability.​
• Bluetti: Provides high-capacity portable power stations suitable for extended off-grid stays, ensuring your campervan’s electrical needs are met.​

Final Thoughts: The Future of Modular Campervans

With more people needing multi-use vehicles, modular campervans are becoming the best solution for those who want both work and leisure in one van.

By designing modular electrical, water, and gas systems, you can make your van:
✅ More versatile
✅ Easier to modify
✅ Cheaper to maintain
✅ Perfect for both work and adventure

With the right quick-connect fittings, removable furniture, and flexible layouts, building a DIY modular campervan has never been easier! 🚐✨

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When designing your modular campervan systems, ensure that all components are compatible and meet safety standards. Consulting with professionals or experienced DIYers can provide additional insights tailored to your specific needs.