TRANSFORMATION OF THE ROZEMAAI HOUSING ESTATE ANTWERP
Modernist housing in decay
The Rozemaai housing estate in the far north of the city of Antwerp was built on a rather isolated urban plot as an extension of the suburban village of Ekeren. The site faces the impressive landscape park "Oude landen" on one side, while on the other side the plot is enclosed by the noisy motorway A12 and the nearby harbour with its large industrial estates. The urban plan was based on CIAM principles and proposed the construction of a series of mainly gallery-accessed slab buildings for social housing that rise up to eight floors in an open park-like setting. The individual architectural projects have been realized during the late 70s and early 80s. The impressive buildings with prefab-concrete façades designed in a brutalist manner encountered various social problems from the beginning that have been - among others - the result of a rather problematic architectural design with limited interaction between the houses, the street and public space. Apart from that, the houses suffered from various technical problems that were the result of poor construction in combination with postponed maintenance which led to an astonishingly quick decay of the buildings. After a long discussion, the housing cooperation finally decided to renovate at least two of the almost ruined buildings. The main argument for renovation was the rather bizarre fact that in case of demolition of the slabs the new urban plan would limit new constructions to a height of up to four storeys. The housing cooperation did not want to reduce their number of apartments in Rozemaai and in order to find a proper architectural solution organised an invited competition in 2011 that was won by Atelier Kempe Thill.
Stripped to the bone
To be able to tackle the various urban, architectural, social and technical problems, Atelier Kempe Thill decided to transform the two buildings in quite a radical way. The starting point was the ambition to improve the integration of the two buildings into the urban framework and to realize a more convincing interaction between the houses and the public space. To ensure this, the building site was cleaned up in three steps. The first step was to remove an existing abandoned 150m long parking garage and several garage boxes that – besides causing social problems like drug dealing - blocked the fluent relationship between the buildings and the surrounding park landscape. As a second step, all existing staircases and lift shafts of the two buildings were demolished to allow organising the access zone of the two flat buildings in a more appropriate way. The final step included removing the concrete balustrades of the galleries and nearly all façades to create a fluent relation between interior and surrounding landscape. At the end of this operation, only the stripped structural skeleton of the two houses remained on-site, forming a good basis for two "almost-like-new" buildings.
A new modernist ensemble
The remaining structures of the two modernist buildings provided a welcoming basis for a new interpretation of the values of modernism: light, space and green. The design focuses on the construction of a clear building envelope and a logical interaction between buildings and public space. The form of the existing skeletons is enhanced by adding more building volume to the top floors of the two buildings to correct the geometry and to yield more rentable surface.
The four new staircases and lift cores are placed at the four closed head façades of the existing structures. This has several advantages; the new cores no longer block the views from within the apartments, the entrance halls are all clearly visible from the surrounding streets and the buildings have more communicative façades at its heads. A welcome side effect is that the buildings have become partly higher and substantially longer, and therefore appear more monumental. The two buildings now form a dominant ensemble with communicating façades and inviting entrance halls. This is underlined by the realisation of a connecting little piazza between the two buildings that is the "entrance gate" to a future little park and a new low-rise housing development on the Westside.
Balconies, panorama and daylight
The existing buildings had been realised without balconies which is rather unusual for a suburban post-war housing estate. The transformation offered the possibility for correction and to give every future apartment a proper outside space which is highly sought after in social housing. In order to do so a structurally independent prefab concrete construction is added to the existing skeletons on the Eastside. The balconies are on average approximately 8m wide and 1.5m deep and give the two buildings on the street side a far more optimistic and communicative character. Balconies are avoided on the ground floor level. In its place, bigger family apartments are realised that are directly accessed from the street to stimulate social interaction between the houses and the public space. The apartments at ground floor level have their outside spaces on the Westside of the building underneath the existing gallery construction.
The existing building skeletons are adapted to realise more convenient apartments that fulfil the higher standards of the 21st century. A new layer is added on the top of the existing gallery to make all apartments accessible for people using a wheelchair. In the skeletons of the two slabs, more than fifty connecting openings are cut with a concrete saw and the existing concrete wind bracing walls have been removed to offer more spacious, bigger and flexible housing types. All apartments now have a full glass façade towards the big balconies that offer fantastic views on the surrounding trees and the large landscape park "Oude landen". Horizontal windows were installed on the gallery side of all apartments often in combination with open kitchens - rather unusual in the context of Flemish social housing. This results in open and friendly apartments with a maximum of space, daylight and flexibility.
Extreme make-over: elegance in social housing
The materialisation aims to realise a maximum of interaction between the housing interiors and the surrounding green public space, and tries to add a certain lightness and complexity to the otherwise massive buildings. The insulated façades are dominated by big windows in light bronze anodized frames in combination with light bronze-coloured corrugated aluminium plates. All the balconies and galleries have glass balustrades in bronze anodized rails. The glass plates cover the concrete plates of the balcony construction and the gallery adding the appearance of a "second skin" to the two houses.
The character of the two buildings is now dominated by the resulting interaction between the inner and outer façades, the reflection of the surrounding and the activities inside the apartments. At ground floor level the two houses got a "plinth" formed by the entrance halls with jumbo glass plates of up to 5.6 m and the façade of the ground floor apartments. This façade is made out of a combination of fixed glassing and extruded profiled aluminium plates. The fixed glassing is partly only translucent to guarantee privacy. The aluminium façade is suppressing the visibility of the entrance doors and the ventilation openings in order to produce a more abstract and quieter façade.
As a result, the project appears as an "extreme make-over" of the former brutalist architecture. Nearly all historic elements disappeared or had to be covered, for various reasons and an almost new architecture is created out of an existing one. Only from the façade of the gallery, one can still recognise the difference between the old and the new concrete plates, but even this memory of the past will disappear with time.
Sustainability and economy: save modernist housing
The resulting project is a very welcome contribution to the debate about the relationship between sustainability and economy. Currently, a lot of the modernistic housing estates are demolished with the argument that it is too complicated and too expensive to adapt these buildings to new standards regarding energy, acoustics and environment. That means that the ambition to produce more sustainable housing is, in fact, stimulating the very unsustainable demolition of the existing housing stock. By maintaining and transforming the existing building structure in Rozemaai substantial CO2-emission of, an otherwise new construction has been avoided and approximately 50% of the existing building material could be directly re-used on site. By adding even more rentable surface to the existing structure, additional consumption of land could be avoided.
The construction process itself required more physical labour compared to a new construction, which could be seen in general as a positive side effect for the labour market. The construction costs (€ 895/m2) are approximately 75% of a new building, while the building standard of both houses is nearly comparable to a new building. The spatial qualities, however, are in many cases better than found in contemporary social housing. From Atelier Kempe Thill's point of view, the project demonstrates the possibilities and the potential of many post-war housing estates and underlines the meaningfulness to renovate these settlements for ecological and economic reasons.
Material Used :
1. Window frames: Kawneer-Alcoa, RT72
2. Doors galleries: Reynears, CS77
3. Insulatedglass: Guardian,ClimaGuardEcoSun70/38
4. Corrugated façade cladding: MN Metall GmbH, Welltec W15/40
5. Floor tiles galleries: Del ConcaCeramica, HDG 215 Rett. GrigioScuro
6. Extruded façade cladding: Almet, Profil Design 213-20
7. Metal gratings façade: Staco,Pressed Gratings RO 30-3 / 33.33 x 66.66
8. Metal mesh façade: Tribelt,Inox HarmonicaMesh Type600: WHG 10/18-1,6
9. Postbox: Larob
10. Lighting galleries: Disanoilluminazione, Sicura
11. Lighting terraces: Zumtobel, Perluce