WLTR bricklaying robot completes first French trials in Essonne

The WLTR bricklaying robot has built its first walls in France. At the end of October, the machine ran a week of full-scale trials on Scale One, the platform Bouygues Construction has just opened in Chilly-Mazarin, in the Essonne department. A first real construction site could follow in early 2027.

WLTR was developed by Czech group GreenBuild with building-materials maker Wienerberger and KM Robotics. The 2.5-tonne machine uses an articulated arm to pick up two bricks at a time from the pallet, apply two beads of foam in place of mortar and position each brick according to the building's digital plan. An operator supervises from a tablet while an assistant handles supply and finishing.

Speed, loads and requirements

On paper, the robot reaches up to 10 m² of wall per hour, 7.5 m² on average, for walls up to 3.50 m high. It lifts blocks weighing 52 kg, the heaviest part of the trade for a mason's back, while drawing just 1.5 kW. It needs three-phase power, a water supply, clear space along the wall and bricks designed for its gripper, from the Porotherm range.

The first trial outside the Czech Republic took place in late 2024, with about 300 m² of walls built in six days on an Austrian warehouse. About a dozen units now operate in Central Europe, from Czechia to Poland, with more than 40,000 m² built. In Budapest, one machine completed the structural work on a 100 m² house in under three days.

One mason, not five

The manufacturer pitches WLTR as the equivalent of a five-person crew. Field results are more modest. At Kladno, near Prague, construction group PORR has used one since 2025 on a 371-home development. Its interim assessment, published this summer, found productivity comparable to a single experienced mason, with two people working continuously around the machine. Quality stays constant from the first course to the last, but cutting, openings and anchoring remain manual. PORR chief Karl-Heinz Strauss says construction "is and will remain a human affair".

The timing suits France's labor shortage. The construction sector had 143,000 hiring plans this year, 65% of them considered hard to fill, a record. A machine that takes over the heaviest lifting could ease the strain even at one mason's pace. Bouygues Construction is already testing drilling robots to reduce physical strain on its sites.