Wienerberger Digs Deep: From Subway Shale to Electric Kilns Amid a Building Slump

Austrian brickmaker invests in circular-economy bricks from metro tunnel waste and a world-first electric kiln, but weak demand and falling shares challenge its turnaround.

The European construction downturn is forcing Wienerberger to fight on two fronts simultaneously. While housing starts dwindle and project developers struggle with elevated interest rates, the Austrian brickmaker is ploughing capital into two radically different pilot projects — one recycling tunnel excavation into clay bricks, the other electrifying a gas-fired kiln in England. Both aim to slash costs and emissions, but the market has yet to cheer.

The more immediate initiative is a circular-economy venture on home turf. Wienerberger has struck a deal with Vienna’s public transport operator, Wiener Linien, to take 35,000 cubic metres of earth excavated from the U2 metro line extension. The soil’s high clay content makes it suitable for brickmaking. Some 2.8 million bricks are expected to emerge from the material — enough for roughly 1,000 single-family houses. Trucks shuttle the spoil nine kilometres to the Hennersdorf plant and also to the Göllersdorf site for processing. The company conserves its own clay pits while cutting landfill disposal costs, and the finished “U-Bahn bricks” will be sold through normal building-materials channels.

Across the English Channel, a longer-term bet is taking shape. On 28 May 2026, construction begins at Wienerberger’s Broomfleet facility on what is billed as the world’s first fully electric tunnel kiln for roof tiles. The unit will replace the current natural-gas-fired furnace. Wienerberger UK & Ireland is running the project as a pilot; if successful, the electrified design will become the blueprint for other plants. The aim is a sharp reduction in CO? emissions from energy-intensive firing processes — but the timing adds strain. The cost of the transition must be financed precisely while the industry is mired in a demand drought.

Investors see little reason to cheer yet. The Wienerberger stock trades at €22.92, barely above its 52-week low of €22.32. Since the start of the year the shares have shed roughly 24% of their value. First-quarter revenue slipped to just under €1 billion, and operating EBITDA fell from €130 million to €97 million. Management has warned it does not expect a swift rebound in residential construction, relying instead on price hikes and tight cost control to defend margins.

The broader figures underscore the headwinds. Real construction orders in Germany dropped nearly 8% year-on-year in March, with civil engineering collapsing 11% month-on-month. A meagre bright spot came from building construction, which rose 9%. Meanwhile rival Strabag climbed 2.3% to €89.50 on Friday, and the ATX index hit a two-week high — offering a contrast to Wienerberger’s persistent weakness. Technically, the shares are locked in a downtrend; a break above the 50-day moving average at €24.06 would signal a potential reversal.

Wienerberger’s annual forecast of around €810 million in operating EBITDA remains the central anchor for shareholders. The company is scouting further opportunities for the circular-economy model, including the planned U5 extension to Hernals and other Danube-region infrastructure projects. Whether either pilot can materially lift margins will become clearer only once volumes ramp up. For now, the stock’s fate hinges on a housing recovery that shows few signs of arriving soon.