Luxembourg's office investment market has just delivered a powerful signal to institutional capital watching the Grand Duchy from the sidelines. Grossfeld, the joint venture between Nextensa and Promobe, has completed the sale of Stairs S.a r.l. to State Street Services Luxembourg, transferring full ownership of a building that has quietly rewritten the country's sustainability benchmark. Delivered on 1 July 2026 in the Cloche d'Or district, Stairs is the first building in Luxembourg to achieve a BREEAM Outstanding certification, the highest tier of the internationally recognised standard.
The deal is Grossfeld's second transaction of the year to clear the €100m threshold, a milestone that underlines the joint venture's staying power in a market where many developers have pulled back. For a buyer of State Street's stature to commit to a newly delivered asset at this scale suggests confidence that prime, certified office space in Luxembourg is not just holding value, it is commanding it.
What makes Stairs stand apart is not simply the headline certification but the density of credentials layered underneath it. The building pairs its BREEAM Outstanding rating with WELL Gold status for occupant wellbeing, an A+ energy rating and a construction approach built around recyclable materials and a green roof. At 9,999 m² across a ground floor plus 11 upper storeys, it offers capacity for up to 975 workstations and 52 underground parking spaces, engineered by Stefano Moreno of Moreno Architecture et Associés.
For investors and developers watching capital flows into continental office markets, the transaction carries a signal that goes beyond this single asset. As financing costs continue to filter into underwriting decisions across Europe, ESG-certified buildings with WELL and BREEAM Outstanding credentials are increasingly emerging as the assets least exposed to obsolescence risk, and the ones most likely to attract institutional capital willing to pay a premium for future-proofed compliance. Stairs may become a reference point for how that premium gets priced in Luxembourg specifically.
The building sits within Cloche d'Or, a district shaped over more than two decades under the New Urban Living model, combining energy efficiency with mixed-use development and direct tram access. The district itself holds a DGNB Platinum certification from the German Sustainable Building Council, and its expanding footprint, anchored by Luxembourg City's largest public park and its own shopping centre, continues to strengthen the investment case for the wider neighbourhood, not just individual buildings within it.
With this closing, Grossfeld reinforces its position as one of the most active and credible players shaping Luxembourg's office landscape, proving that ambitious sustainability targets and landmark-scale transactions can, in fact, reinforce one another rather than compete.
People mentioned:
- Stefano Moreno – Architect, Moreno Architecture et Associés
Companies mentioned:
- Nextensa – Investor and developer, joint venture partner in Grossfeld
- Promobe – Luxembourg property developer, joint venture partner in Grossfeld
- Grossfeld – Joint venture developer of the Cloche d'Or district and seller of Stairs S.a r.l.
- State Street Services Luxembourg – Buyer of Stairs S.a r.l.
- German Sustainable Building Council (DGNB) – Certification body for Cloche d'Or's DGNB Platinum rating
