150 Holborn unites London-based members of the Sidara Collaborative—Dar, Perkins&Will, Portland Design, Currie & Brown, Introba, Maffeis Engineering, and Penspen—under one roof.

This state-of-the-art workplace accommodates over 1,000 staff who, together, are committed to advancing ecological health and well-being through design and engineering. The building fosters collaboration and the exchange of ideas between Sidara member firms, while also ensuring each firm retains its unique identity.