Roof garden Rabobank Headquarters Utrecht by Baljon landscape architects

2023 Campuses and Corporate / Netherlands / Built in 2020 /
baljon.nl/

CONTEXT – The garden of 5,500 m2 is at the centre of the headquarters of the Rabo-bank, accommodating 6,500 employees. Through the staff restaurant and café, at two levels, the garden is accessible.

STARTING POINT – The original garden was stony and created just to be looked at from the buildings. It consisted of three parts: a high retaining wall with a small group of Grey Poplars (at the end of their lifespan) on top, a shallow architectural reflecting pond (leaking) and a stepped sculptural landscape of stacked concrete tiles. A stainless steel needle was the prominent centre. The garden was in a poor state, due to crumbling construction, murky water and lack of vegetation.

CONCEPT – The design is based on three main interventions, transforming the garden from a harsh, stony ‘viewing’ garden to a lush ‘residential’ garden that maximises biodiversity, retains rainwater, and offers ample seating opportunities and outdoor spots for informal meetings.

First intervention: remove the high and forbidding retaining wall and replace it with a terraced landscape leading towards the pond. Connecting the parts of the garden visually and functionally this unifies the garden.

Second intervention: cover the bare forms of the artwork with a floral blanket. The steel needle is kept in its central position; preserving the essentials of the original artwork, it is transformed into a lush, ecologically rich and pleasant environment. And integrate a substantial water buffer, and include inviting outdoor spaces for meeting, work and relaxation.

Third intervention: add routes through the garden, connecting different levels in the building and the garden. A winding path through the flower garden leads along sculptures from the company’s art collection; on small plinths they seem to hover above the flowers.
The terraced garden hosts an orchard and herb garden, encouraging a healthy lifestyle.
At the top level a long bench with a high backrest terminates the garden.

Motivation

CONTEXT – The Rabo-bank has an agricultural origin. This is expressed in the drastic transformation (as part of renovation and extension of the whole complex): it is designed as an edible garden for people and animals. Much of the garden is laid out on top of a basement of different levels. The design responds to this complex underground structure.

CONDITIONS – Much attention was given to analyse conditions (wind and sun) to refine the overall design and make a fitting planting scheme. Also at this level the design required precision. The planting plan is based on ecological research: which species live in this urban landscape with so many urban barriers. Which species and can be attracted and facilitated? The flower garden is largely in the shade of the building. But the glass mirror facades reflect so much light that there are still light and sunny spots. A detailed survey with light meters helped to map these.

TECHNICAL CHALLENGES – For the steep sloping parts of the roof, a special substrate matting had to be developed. The existing pond is restored, but with new functions integrated: rainwater buffering, natural banks that purifies the water and keep it healthy, and bring the ecological potential of water in an urban environment to life.

APPRECIATION – The garden forms a lush environment at the heart of the office complex, much used for informal gatherings, and much loved as lunch spot. It also brings nature at the doorstep: an abundance of colours and textures of the vegetation and, together with the ecologically sound pond, various birds, butterflies and dragonflies.