599-New head offices for Cenaero and Cetic

– Architecture
– Daylighting
– Interior design
– Landscaping
– Structural engineering

The companies Cenaero and Cetic are joining together to build new operating bases in the same building, however each company wishes to remain identifiable independently from the other.

The proposal is based on the concept of the New World of Work (NWOW), which shares office spaces and equipment for fully or partially nomadic employees.  Each user can choose their working position according to the type of activity: concentration or communication work, individual or group work, standing or sitting, on an office chair or sofa.

Given the nomadic nature of personnel, the project only plans non-personalised work stations for 70 to 80 % of personnel.  This provides additional floor space which could be rented temporarily to a third party.

Document E41_01/ 599 -En Issue of 2013-06-21

The curve of the land, the unstructured visual environment and the idea of flexibility encourages the devising of a regulatory design, made of multiple ellipses. Three elliptical rings of increasing diameter, above an open-air ground floor, make up, successively, the floors of the first and second floors, intended for Cetic and Cenaero respectively, and the roof garden.  The two foyers of the smallest ellipse, marked by the two vertical circulation cores, symbolise the dual occupation of the building.

As such, the site is entirely free and reserved for access areas and for a garden populated with large trees.

The vast ground-floor space is reserved for the reception gallery, surrounding a central pond.  A 16-m-wide elliptical spiral ramp disappearing into the ground covers the car park which is naturally lit and ventilated via large outer openings.  The gradient is under 5 % to allow access for people with reduced mobility.

Visitors access the two outside vertical transfer hubs either via the gallery or directly via the car park.

Outside stairs, with very gentle gradients, spiral out around cylindrical panoramic lifts, providing access to the two office floors.

The arrangement of the elliptical sheets is meant to be as fluid as possible.

All acoustic separation partitions (absorption and insulation) could be created using multicoloured fabric curtains, the rails of which, attached to the wooden ceiling, could be easily rearranged as needs change. This is an opportunity for the highly qualified occupants to express their interests.

Fabric ‘clouds’, lit by LEDs and attached to wooden floor slabs act as light diffusers and reflectors, as well as absorbing sound.

The green roof is made into a garden.

The floor height (3.96 m) is comfortable and provides both plenty of height under the ceiling (3.06 m) and good floor thickness (90 cm), which allows an economical structure and an especially flexible inclusion of building services.

The height also allows deep natural lighting, permits excellent views of the outside and promotes group work in wide open spaces.

The structure is a mix of steel and wood.

Two sets of 24 steel columns are spread along the two ellipses close to the outer and inner windows.  80-cm-high steel lattice work connects them in pairs to each level. This height of the structure is the most efficient for transferring the weight of the floors while allowing technical components to pass through.

The solid, laminated, nailed boards, 25 cm thick, are supported at the bottom by lattice work and provide fire protection for them.  These floors also make up the ceiling of the floor below. Their outsides are thermally insulated.

They support 60-cm-high columns, placed on a regular square grid with sides of 90 cm and support the surfaces people walk on on each floor.  This creates a vast plenum under the ceiling to hold the sanitary, airflow and electrical equipment of the building.

Four vertical sets of bracing made from steel lattice work are placed in line with the main axes of the ellipses and thus allow free thermal expansion.

The infrastructure containing the car park and technical areas is created using a fire-retardant wooden floor.

The elliptical supporting walls made from drainable and green geotextile run alongside the side window wells.

The foundations are made using compacted, unbound materials in fabric ‘socks’, meaning that the entire structure can be fully dismantled and recycled.

The sides are made from floor-to-ceiling double glazing, the wooden floors and ceilings act as the frame. Openable small frames, made of oak and which are well sealed, are spread at regular intervals in these large faceted elliptical cylinders.

The double glazing is made of ultra clear glass, without selective layers.  This is because experience and calculations show that using double glazing with a ‘low emissivity’ layer to improve insulation would paradoxically result in higher overall energy consumption. The increase is due to additional artificial lighting resulting from the reduction of light transmission which far exceeds the gain from improved insulation.  The transparency and colour yield is also much better and conforms better to our vision.

Vertical, revolving strips protect the outer facings from solar heat, without reducing the view or light.

A transparent cover made from ETFE, in the shape of a funnel, covers the inside pond and provides a ‘reverse fountain’ when it is raining. In the walking gallery it extends above the roof garden.

The entire building has a very low thermal inertia, which provides immediate responsiveness to variations in energy needs.  The necessary thermal mass is externalised in a large compartmentalised water container under the pond.

The artificial lighting is provided via high colour-yield LEDs (RA > 92 %) in the white acoustic clouds.

The air-conditioning system is designed to achieve the ‘zero energy’ level.

Use is made of recyclable natural materials, ideally those labelled ‘Cradle to Cradle ®’

In the same way, the floors are made from light oak and the carpet from second-hand wool (a refined and cheap option) or, if you wish, from pure-grey recycled polyamide-fibre slabs.

The vertical walls are made from wood or fabric.

The solid wooden structure of the ceilings remains visible and is supplemented with the fabric ‘clouds’.

The wooden furniture should express the friendly character of the areas and could include a suitable selection of second-hand pieces.