At the entrance of the Val d'Illiez above Monthey, Troistorrents combines a Chablais village with the resort of Morgins in the Portes du Soleil.
Troistorrents tracks Valais closely, at CHF 5,800 per m² for a flat. Communes in this band are the easiest to value: enough sales to anchor a price, and no local anomaly pulling the figures around. The premium over Valais has a practical effect at resale. Buyers arriving from cheaper communes negotiate hard on condition, because they are already stretched on the price per square metre before they walk in. Position 24 of 67 in Valais puts Troistorrents among communes with similar price levels and often very different housing stock. Two communes can share a rank and still value the same flat differently once age and condition are taken in.
A house in Troistorrents is valued around CHF 6,300 per m² against CHF 5,800 for a flat, a gap of 9 percent. Land is what separates the two figures, and the scarcer the building plots, the wider that gap runs. The last twelve months added 3.3 percent in Troistorrents. Rises of this order usually come from a shortage of listings rather than from a wave of new buyers, and they unwind faster than they build.
Against the Monthey district the gap comes to 6 percent. This is the comparison that carries weight for an estimate: communes in one district share a labour market, a transport network and the same pool of buyers. The largest group of homes in Troistorrents, 18 percent, dates from after 2015, with the rest spread across the other bands. Where stock is this varied, a commune price per m² carries less weight and the comparison has to come down to buildings of the same age.
Average size in Troistorrents is 98 m² across 3.7 rooms. Compare your own property with that figure before you read any price per square metre: an outsized home rarely sells at the local rate, and a small one often beats it. Half the flats sold in Troistorrents went above CHF 5,800 per m² and half below, which puts the commune 5 percent from the Valais median. One exceptional sale barely moves a median, and that is why we use it instead of an average. Over 25 years the median moved from CHF 3,700 to CHF 8,200 per m², a change of +122 percent. That is the market, not your property: a flat renovated in the meantime followed a different curve entirely.
Enough properties change hands in Troistorrents each year to keep the price data steady. Estimates land in a narrower range here, and a valuation can lean on recent comparable sales instead of falling back on the cantonal average. Knowing the median in Troistorrents gets you halfway. The second half is what separates your property from that median: condition, orientation, outside space, parking, and the works still to be done.
Building stock data: Federal Register of Buildings and Dwellings, FSO, updated August 3, 2026
Market data updated on August 24, 2026
A range set against the price levels of your commune and the profile of your property.
Value my property →Around CHF 5,800 per m² for a flat, which is 5 percent from the Valais median. Houses are priced separately and usually land somewhere else entirely, so work from the figure that matches your property type.
The reference is CHF 6,300 per m² in Troistorrents. It averages a small number of sales, since houses change hands far less often than flats, so treat it as a bracket to work inside rather than as a price.
The dominant band in Troistorrents is after 2015, which covers 18 percent of homes. Average size runs to 3.7 rooms, so the commune is built mainly for households rather than for single occupants or short stays.