Renewal and revival of celebrated 1970s modernist offices and gardens unveiled at Plant Basingstoke

Grant Associates is part of a team of leading architects and landscape designers to complete the heritage-led redevelopment of the former Mountbatten House in Basingstoke, one of Britain’s 15 most important listed modern buildings.

Originally designed by Peter Foggo and Arup Associates Group 2, the building and gardens received an RIBA award in 1979 and were both Grade II listed in 2015 for their design excellence and significance within modernist architecture and horticulture.

The redevelopment of the building and gardens continues this collaborative spirit, blending conservation with thoughtful redesign and delivery to ensure the building’s future appeal and success. Architects Feilden Clegg Bradley Studios and landscape architects Grant Associates led the overall concept and detailed design. Twelve Architects and landscape architects Studio Knight Stokoe were brought on board to sensitively manage the design and delivery phase.

Mountbatten House, originally known as Gateway House, was designed in 1973 for Wiggins Teape and features six levels of commercial workspace integrated with tiered roof gardens by renowned garden designer James Russell. The building’s seamless blend of architecture and landscape remains a hallmark of British modernism.

Rebranded as Plant Basingstoke, Plant marks a major regional asset for economic development in Hampshire, offering over 19,515 square metres of category A and B multi-let office and amenity space. The design team has worked closely with the client, Mactaggart Family & Partners, developer Longstock Capital and contractor, CField Construction, to reinstate the buildings’ original pioneering design intent; to blend nature, wellbeing and the workplace seamlessly. Client William Laxton of Mactaggart Family & Partners was instantly drawn to the scheme on account of the original Peter Foggo design fundamentals and the abundance of terracing, making it a singularly unique asset.

In aspiring to the highest sustainability ratings across BREEAM 'Outstanding’ and WELL Platinum certifications, Plant again pioneers a new commitment to the environment and occupant that sets a remarkable standard for future commercial workplace developments.

A key driver of the project was to greatly improve access to the gardens and roof terraces, with new level access from all storeys allowing greater use and enjoyment of the much-loved and affectionately termed ‘hanging gardens of Basingstoke’.

Through extensive research conducted in archives at the University of York - including Russell’s handwritten planting lists - the listed landscape has been designed to be climate resistant and importantly, regenerative. In-depth analysis of the historic planting palettes was undertaken, replacing plant species poorly suited to exposed rooftop conditions and prioritising species that are better suited to their environment, fostering biodiversity enhancements by helping pollinators and foragers to thrive.

Over 22,500 new plants have been introduced, along with 86 new trees to complement those already on the site. With no raised planters across the gardens, adapting the planting required close collaboration between the landscape architects, structural engineers, and soil specialists, ensuring even loading across the multi-level structure. The renewed planting design draws inspiration from the original design vision for the gardens; to be informal, elaborate, romantic, overflowing, and tumbling.

Much of the existing hardworks have also been restored, with every original paving element across the garden levels recorded and catalogued, before being temporarily removed through construction, and then replaced in-situ. A deteriorating pond has been replaced in the cloistered Level 2 courtyard with a sculpted contemporary water feature, honouring the original form of the pond, and helping to bring new sensory experience into the space.

The revitalised gardens enhance biodiversity and create inclusive, engaging spaces for both occupants and visitors. Winding pathways and new seating areas invite exploration, offering opportunities for relaxation, socialisation, and quiet reflection.

A widely regarded exemplar of British modernism and commercial horticulture, Plant now begins its new life as a regional hub for growth, providing the right environment for office workers and nature to thrive.

Prominent architectural interventions include a redesigned and expanded building entrance and reception area, enhancing the arrival experience and establishing a stronger visual connection to the verdant refurbished gardens. Double-height spaces have been formed to create vertical connections between floors, increasing the sense of openness and drawing more natural light into the plan. A striking helical staircase marks an impressive, welcoming entrance area for building users.