zoka zola architecture + urban design    1737 west ohio street   chicago IL 60622    t 312 491 9431    f 312 491 9432    info@zokazola.com

Mixed-use development

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view of the site

The site is in the Northern district of Liege one and a half kilometers from the urban center. It is bordered on the north side by the railway line, which separates it from the hill of the Citadel and the Fabry wood. To the south and the west, the road and the square Vivegnis constitute its limits and allow access. A footbridge connecting the area with Fabry woods is required.

First used for a coal mining industry, the site was later used for a brewing industry and has recently been cleared and leveled. The remaining buildings on the site are used for a Turkish community center and an art gallery. Open flat ground is used as a football field and playgrounds.

This city area has a high unemployment rate and a crime problem. Leige's urban policies are to stabilize the population, to attract new inhabitants, to preserve the diversity and conviviality of town life, and also to create green spaces.

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aerial view

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foundations without and with basement area
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edge detail of grass covered roof


view from east

Proposed Roof Structure
Most of our proposed structure is the grass covered roof. This roof is rising from the street level toward the green hill of Fabry woods. The views to the Fabry woods are thus preserved. The existing soccer fields and casual playgrounds are "peeled" off the ground and placed on the new roof structure.


Existing Site - Use and Views
The site is a grassy surface used as casual sports grounds. It provides a relief from the dense residential street pattern. It also provides views to the hillside of Fabry woods.

Indeterminate Use
The shapes and the heights of the roof structure are designed to house a maximum variety of functions underneath it and on top of it: from sport halls, department stores, lecture halls, offices, exhibition spaces, warehouses, to small shops, cafes, studios, workshops, housing or community centers.

Wall enclosures
The future users are to build their wall enclosure depending on their needs. The proposed structure allows for its future misinterpretations without loosing its design integrity.
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detail view from southeast

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view from southwest

    Specific instead of neutral structure
The flexibility of uses is here achieved by specific structures, instead of the usual way of achieving flexibility by providing a neutral "vanilla box" structure.
In this proposed specific structure different parts of the building are not in tension but are balanced, and are given equal values, thus are less determinate about their use.


The structure consists of 50 self-contained areas with their own access, services, sunlight, ventilation and fire exits. These areas can be combined in a number of different ways into larger areas. Because the building is built by a developer as a shell state, the developer's inital costs include foundations, steelwork frame, ground and upper slabs, staircase structure and roof only. Floor to ceiling heights vary between 2.6m and 6.7m.
An unusual feature of the scheme is the provision of grass covering to the roof areas necessitating a built-in irrigation system.
One exception to the limited shell state is the mezzanine level to the west side, which includes an enclosing wall around an a owner built restaurant. Otherwise, like the remainder of the project, the occupier carries responsibility for the fitting out.

The project also features an underground car parking for a total of 314 cars located in both west and east areas, terraced seating to a possible sport hall or performance area on the east side, and a 75m span footbridge connecting the north end of the site with adjacent land.

Landscaping work between buildings consists mainly of earth moving to create a contoured site, grassed, but with minimal provision of hard landscaping, trees and planting. Underground drainage, gas, electrical and telephone service entries have been included into each building.

Areas (m2) Total building area (excluding carpark in the basement) 7.710m2 Total site area (excluding art gallery and Turks community centre) 9.472m2
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view from west

diagram of self contained areas


The structure of the proposed building may be divided into four principle elements.
1) A canopy roof supported on freestanding columns protects a ground slab covering most of the site area. It is a continuous plate structure formed by two-way spanning bays of variable width. The plate element is supported along one lower edge to provide lateral and longitudinal resistance to horizontal loading. The deck supports grassed areas and pedestrian terraces and is formed as a double skin of continuously welded steel plates fixed to a triangulated internal frame to form a structure of high stiffness relative to overall weight. The canopy is supported internally and along three sides on concrete columns, articulated at the top junction and fixed at each base. Columns bend along their height to accommodate thermal movement in the canopy itself. There are no structural movement joints.

(2) Beneath this canopy, mezzanine floors are inserted on a secondary grid of lightweight columns. Additional accommodation is provided in single story enclosures, insulated within the overall space, protected from the weather by the main canopy. The mezzanines are floors of composite lightweight concrete and steel decking on cold pressed steel beams and secondary columns. Areas of floor could be hung from the main canopy to allow for column free area s below.

(3) Screen walls surround the canopy perimeter to complete the weather envelope. The screen walls are either freestanding, framed in steel with lightweight cladding, or suspended glass screens supported at eaves level. They resist lateral wind loadings through cable bracing mullions and transoms.

(4) Future provision for the basement is accommodated by the substructure arrangement.

There are two ways of completing the structure. The main roof could be assembled on the prepared base of the ground and then jacked into place onto precast columns or temporary staging. Alternatively, the inner triangulated lightweight frame of the main canopy could be fixed in its final position and skinned in metal sheet to complete the load bearing system. Both systems allow for the rapid completion of the roof so that the perimeter walls can be added to achieve an early weather tight date. Once the perimeter screens are completed, the interior accommodation, mezzanines, and modules can be installed and finished.

The foundations of the main structure are simple deep spread footings sized to resist the imposed loads of the various column sizes. The lower edge of the main canopy roof will be fixed to a reinforced concrete retaining wall structure. The main floor slab is a simple ground bearing concrete mat reinforced with ground beams at the perimeter to support the external walls.

Provision is made for the future installation of a basement accommodation area or car park. The foundations in the area designated for the basement are formed as piles sleeved through the lower story area into the strata below. The perimeter walls are formed as diaphragm walls or contiguous piled walls installed from ground level. The ground floor slab above the future basement is reinforced to act as a future suspended slab. When the basement area is required, then the area is excavated within the prepared walls, a basement slab is installed and waterproofed to provide the required standard of accommodation. Areas of ground slab previously prepared as knock out panels are removed and staircases are installed.
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view from northwest

view of bridge over railway


view from east

©Zoka Zola 2004

Client: Provincial Industrial Society of Liege
Design: Zoka Zola, Natalia Maximova
Structural Engineer: Techniker