One Portsoken Street stands as one of the largest design and build projects ever completed in London. Over a 76-week programme, the goal for this 233,000 sq ft development was to transform the building into Grade A office space. Originally constructed in the 1980s, One Portsoken Street is located on the edge of the City of London. Alfred Equities, a forward-thinking developer, selected Oktra to fit-out and revitalise the entire building, recognising its immense potential and utilising an innovative construction method that minimised risk while enabling the developers to achieve completion in record time.

Design and build leaders Oktra pushed the boundaries of design and build by gutting the building and filling what was once the largest atrium in Europe. This project included a nine-storey atrium infill, with the installation of 27 piles at a depth of 20 meters. This interior reconfiguration resulted in a 20% increase in lettable space without the need to add extra floors. The new floorplates, ranging from 10,000 to 30,000 sq ft, are designed to accommodate up to three separate tenants, each benefiting from high exposed ceilings, abundant natural light, improved destination control with nine new lifts, and a striking lobby space featuring a two-and-a-half-storey atrium.

The refurbishment also included a full restoration of One Portsoken’s original Brutalist design elements, preserving its architectural history while integrating modern finishes that complement the building’s character. Notable features include circular turrets, exposed concrete, terracotta floor tiles, exposed steel beams and sweeping views of London from the top floor beneath the original glass ceiling of the atrium.

The design for the building’s ground-floor communal space features a minimalist concierge desk, strategically positioned away from the main circulation routes to create a clear and welcoming reception foyer. Brass trims and igneous stone tiles give the reception area a premium, natural feel, while acoustic panelling adds comfort and texture to the walls. Every detail was meticulously chosen to enhance the workplace experience, with a focus on quality craftsmanship. The result is a sleek, sophisticated design that has given One Portsoken Street a unique and distinct identity.

Below is a selection of highlights from my photography of this iconic London design and build project.