Choosing the right base van is the single biggest decision you’ll make in a conversion. Get it right and everything downstream — layout, storage, sleeping arrangements, how you’ll actually use the van day-to-day — gets easier. Get it wrong and you’ll spend the next few years working around a compromise you didn’t need to make.
Here at our Darwen workshop, we’ve helped Lancashire and North West customers work through this decision on every kind of build, from weekend micro-campers to full-time live-in conversions. This guide covers what each size class actually gives you, where they fall short, and how to think about it for how you’ll use the van.
The naming: what L and H actually mean
Manufacturers describe van sizes with two variables: length (L1, L2, L3, L4) and height (H1, H2, H3). L1 is the shortest wheelbase, L4 is the longest. H1 is the standard roof, H2 adds a raised roof, H3 is the extra-high option most common on long-wheelbase vans.
You’ll see the same system on the Ford Transit, Fiat Ducato, Citroën Relay, Peugeot Boxer, Renault Master, and Mercedes Sprinter. Volkswagen name their T6.1 sizes slightly differently but the principle is the same.
L1H1 — the compact option
Length: usually around 5m. Interior height: around 1.6–1.7m — you cannot stand upright inside.
L1H1 vans are the smallest full-size conversions. Think short-wheelbase Ducato, Transit Custom, or VW T6.1. They fit in standard parking spaces, are easy to drive, don’t attract low-bridge worries, and often fall within regular car park height limits.
The trade-off is space. You cannot stand up inside, storage is limited, and most builds have to fold the bed down onto the seating area every night. Good for weekend trips, festivals, surf missions, or anyone who values driveability over interior room. Poor for long stays or anyone over about six foot.
L2H2 — the sweet spot
Length: usually 5.4–5.9m. Interior height: around 1.9m — most people can stand upright inside.
L2H2 is the most popular conversion size for a reason. You get real standing headroom, room for a proper kitchen down one side, and enough length for a fixed bed across the back with storage underneath. Most models fit in a standard driveway and most car parks (watch height barriers on the H2 roof — usually 2.5–2.7m).
The Fiat Ducato, Citroën Relay, and Peugeot Boxer L2H2 are the workhorse choice for UK converters. Slightly less nimble than an L1 but still perfectly manageable for daily driving.
L3H2 — the full-time build
Length: usually 5.9–6.4m. Interior height: around 1.9m.
The L3H2 adds significant length without adding height. That extra 40–50cm inside the van makes room for a proper bathroom, a bigger kitchen, or more storage — the kind of things that make full-time or extended-stay van life practical rather than compromised.
Downsides: harder to park, tighter in city streets, more expensive to buy and run. If you’re building a van you’ll live in for weeks at a time, or you need a bathroom with a toilet and shower, this is likely your size. If you’re building a weekend camper, it’s overkill.
How to actually decide
Forget the specs for a moment. Ask yourself three questions:
- How many nights a year will you sleep in it? Under 30 nights, an L1H1 is probably enough. 30–100 nights, L2H2. Over 100 nights or full-time, L3H2.
- Do you need a fixed bed, or will you fold it down each night? Fixed bed = L2H2 minimum, L3H2 ideal.
- Do you need a bathroom? Full wet room with toilet and shower = L3H2. Portable toilet or none = L2H2 is fine.
A word on payload
The other spec sheet number that catches people out: payload (the weight you can add to the van before hitting its maximum gross weight). A full conversion — furniture, water, batteries, gear, passengers — can easily add 400–600kg. On a standard 3.5-tonne van with a payload of 800–1,000kg, that leaves margin. On the lightest L3H2s with heavy factory options fitted, you can eat through the payload fast. Check this before you buy, not after.
Talk it through before you commit
Every conversion we build starts with a conversation about what you actually want the van for, not what the brochure looks good in. If you’re at the base-van shortlist stage and want to talk it through, get in touch — we’ll give you a straight answer on which size suits what you’re planning, whether or not you end up having us do the build.