Buying a used tiny house: checks and pitfalls

The second-hand market is attractive for a good reason: the depreciation is real, and a well-maintained house can last as long as a timber-frame house. It also attracts abandoned projects, unfinished self-builds and houses that have let in water. Here is how to tell the difference.

What exactly are you buying?

Two items in one, and that is the key to everything else. On the one hand a trailer, in other words a vehicle, with its registration certificate (carte grise), its gross vehicle weight rating (GVWR) and its mechanical condition. On the other a house, with its frame, insulation, services and equipment.

A serious seller documents both. If the trailer’s papers are missing, the rest of the viewing is of little interest: without registration, the house cannot legally travel on the road, so it can neither be delivered nor resold to a buyer elsewhere.

How do you check the trailer?

1. The registration certificate: it must exist and match the item. A trailer with a GVWR above 500 kg must be registered.
2. The GVWR compared with the actual weight of the finished house: an overloaded trailer is dangerous and banned from the road.
3. The axles, suspension and brakes: play, corrosion, condition of the tyres, manufacturing date of the tyres.
4. The chassis: corrosion under the house, especially at the anchor points, where water collects.
5. The lights and signalling, to be tested before considering any move.

The rules on weight, width and driving licences are set out in our guide on transport, licences and trailers.

Which signs should make you walk away?

Water is the number one enemy of a wooden house, and it leaves recognisable traces:

• tell-tale water rings on the ceiling, around roof windows and where flues pass through;
• any black spots in the lower corners and behind furniture;
• a floor that gives or sounds hollow, a sign of waterlogged insulation under the house;
• a musty smell that does not go away after airing;
• cladding that has greyed unevenly, split or come away at the ends;
• a ventilation system (VMC) that is missing, disconnected or clogged: it is often the cause of everything else.

If possible, view after a spell of rain, and take a hygrometer with you. The mechanisms are explained in our guide on damp and ventilation.

How do you judge insulation you cannot see?

It is the most expensive item to put right and the easiest to hide. Since you cannot open up the walls, there are three methods:

1. Ask for the original documents: quotes, plans, technical data sheets, construction photos. A serious builder provides them, and so does a careful self-builder.
2. Touch the walls on a cold day: a wall that is noticeably colder than the others points to an insulation defect or a thermal bridge.
3. Look at the window surrounds and the floor-to-wall junction, the two places where corners are most often cut.

No thermal regulations apply to a tiny house on wheels in France: there is therefore no guaranteed minimum performance. See our guide on insulation.

Which guarantees, depending on the seller?

This is the most important difference, and the most overlooked:

• From a professional seller: the legal guarantee of conformity (garantie légale de conformité) applies for two years from delivery, with a presumption that the defect existed at the time of sale. The warranty against hidden defects applies on top of it.
• Between private individuals: the legal guarantee of conformity does not apply. Only the warranty against hidden defects (garantie des vices cachés) under article 1641 of the French Civil Code applies; it must be invoked within two years of discovering the defect, and no later than twenty years after the sale. The burden of proof lies with the buyer.

This difference often explains the price gap between a used house sold by a private individual and one taken back and resold by a builder.

Which papers should you ask for?

• the registration certificate of the trailer and the certificate of transfer (Cerfa 15776), the declaration of transfer being made online;
• the original invoices for the house and its equipment, on which any builder’s warranties still running depend;
• the manuals for the appliances: ventilation, heating, water heater, solar panels;
• the certificates of compliance for the electrical installation and, where applicable, for the wood-burning appliance and its flue;
• the maintenance log if there is one: cladding treatments, chimney sweeps, filter changes.

How do you assess the price?

There is no official price guide. Three practical benchmarks: the price of an equivalent new house, the age and actual condition, and above all the scope — a house sold with its registered trailer and its equipment is not comparable with a shell to be finished.

Two adjustments should always be applied to the asking price: the cost of transport to your land, and the cost of the repairs identified during the viewing. Our published new-build prices serve as a point of comparison: see the prices page and the guide on what the price includes.

As for value over time, the reality is simple: a tiny house depreciates like a capital good, more slowly if it is well designed and well maintained. That is the subject of the guide on lifespan, maintenance and resale.

The land trap

A used tiny house is sometimes sold “installed”, with the implicit promise that it can stay where it is. That promise is worthless: planning authorisation goes with the land, not the house, and it is not transferred from one sale to the next.

So before buying, check your land, not the seller’s. See our guides where to put a tiny house and non-buildable land.

Key points

• You are buying a trailer and a house: both need checking, papers included.
• Damp is the deal-breaker; you can spot it from water rings, smells and the floor.
• Insulation cannot be seen: ask for the original documents.
• Between private individuals, only the warranty against hidden defects applies.
• The authorisation to site the house is not passed on with it.