Guide
BS 3632 or EN 1647: which standard your lodge is built to, and why it changes the interior
Most people specifying a lodge interior never ask which standard the shell was built to. It is worth asking, because it determines how the building behaves in winter, and that determines what happens to your textiles.
6 min read · Updated August 2026
The short answer
BS 3632 is the British standard for units built for year-round residential occupation; EN 1647 is the European standard for caravan holiday homes used seasonally. BS 3632 sets substantially higher requirements for insulation, moisture control and acoustics — which changes what an interior specification has to cope with.
The two standards
BS 3632 covers residential park homes intended for permanent, year-round living. The current edition is BS 3632:2023. It sets requirements across structural integrity, thermal insulation, moisture control, ventilation, fire safety and acoustics.
EN 1647 (currently EN 1647:2018+A1:2021) covers caravan holiday homes intended for temporary or seasonal occupation. Its insulation requirements are materially lower, because the unit is not assumed to be occupied through the winter.
Why the distinction is not academic
A BS 3632 unit can normally be lived in year-round, is usually a prerequisite for a structural warranty such as Platinum Seal, and is the specification that makes lender interest plausible.
An EN 1647 unit is cheaper to build and entirely appropriate for a park that closes over winter. What it is not is a building that will be kept warm and ventilated for twelve months.
What this changes about the interior
An unheated, unventilated unit standing through a wet winter is a condensation risk, and condensation is what ruins mattresses, upholstery and curtain linings between seasons. The interior specification has to account for the shell it sits inside.
In practice that means favouring mattresses that can be stood on edge and ventilated over the closed season rather than left flat on a solid base; preferring removable, washable covers over fixed upholstery in units that go cold; and being cautious with dense natural fibres in seasonal units, where synthetic and blended constructions dry faster after a damp spell.
What the Caravan Act allows
Whichever standard the unit is built to, its dimensions are governed by the statutory definition of a caravan. The current maximum sizes are:
- Length — 20 metres, excluding any drawbar.
- Width — 6.8 metres.
- Internal height — 3.05 metres, floor to ceiling.
NCC approval and warranties
The NCC badge of approval is separate from both standards. It indicates that a unit's habitation features (ventilation, alarms, step heights and similar) have passed the National Caravan Council's checks. It is a safety and quality mark rather than a design standard, and it interacts with insurance.
Structural warranties are a third thing again. A ten-year structural warranty will normally require the manufacturer to demonstrate the unit was built to BS 3632, which is one of the more common reasons a park specifies the higher standard.
Common questions
BS 3632 vs EN 1647, in short.
Can a lodge meet both standards?
Some manufacturers build to BS 3632 while keeping the unit within the Caravan Act size limits, which is what makes the more open site planning position available alongside a residential specification. It is achievable but it constrains the design.
Does the standard affect what furniture I can fit?
Not directly, but it affects access. Everything has to come through the unit's own door openings, and in a twin-unit that is assembled on site the sequencing matters — which is why fixed seating and large upholstery are usually built in sections.
Which standard should a new holiday park specify?
It depends on whether the park trades through the winter and whether units will be sold with finance attached. A park that closes from November and sells units outright often has no reason to pay for BS 3632. One doing either of the opposite usually does.
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