Cheap French communes are not the risky ones
A €200,000 budget buys 126 m² at the national median. The assumption is that the cheapest places are cheap because something is wrong with them. Across 31,092 communes the data says the opposite: hazard exposure rises with price, not against it.
There is a tidy story about cheap property: the discount is a risk premium in disguise. Somewhere in the file sits a flood plain, a subsidence zone, something the seller would rather not lead with. It is a reasonable thing to assume, and in France it is backwards.
We took every metropolitan commune carrying both a transaction price and a regulatory hazard score — 31,092 of them — sorted by price per square metre, split them into four equal groups, and counted how many in each group score 3 or higher on the 0 to 7 hazard scale.
Exposure rises with price
The cheapest quarter of the country is the least exposed and the dearest is the most: 32.2% against 55.7%. The gradient climbs at every step in between.
Why it runs that way
Regulatory hazard concentrates where water and people do: coastlines, river valleys, dense built-up land. Those are also the places that command a premium. The relationship is not that hazard makes property cheap. It is that the geography carrying the premium is the same geography carrying the exposure.
Cheap communes are mostly cheap for duller reasons — distance from work, an ageing population, a thin market with few buyers. None of that appears in a hazard register.
What this figure cannot tell you
The hazard score is a municipal figure and exposure is zoned street by street. A commune scoring 0 can still hold a plot in a flood zone, and one scoring 6 can be dry on the hill. Use the municipal number to build a shortlist, never to clear an address.
Two further limits, stated plainly. Price per square metre is the median of recorded transactions in communes with at least five sales — communes below that threshold carry no figure and sit outside this count entirely. And the overseas départements are excluded here, because their transaction volumes and price basis are not comparable with the mainland.
Open the property layer, add hazard on top, and the pattern shows without any of this arithmetic: the expensive coast is not the safe one.