Noise Free Housing

demi-cratère

Peadar McGrath Architect

Noise Free Housing Site strategy The top priority in this housing project was to dampen the noise emanating from two sources: the busy motorway located 60 metres from the site and the constant traffic of airplanes taking off and landing at the nearby Geneva airport, which is located 1 km to the north of the site.

In order to cope with the presence of the motorway, we suggest to modify the existing topography, thus increasing the height of the embankment which separates the site from the path which flanks it to the east. This first action will create a large mass of earth, almost like a manmade half-crater, that will become a screen against the soundwaves flowing from the motorway to the site, leaving the latter in a sunken position.

The path that skirts the site will be used by occasional traffic (visitors, deliveries) to access a new dead-end street that will cross the site on its western flank. Residents will access the underground carpark from the existing ramp located on Chemin de Poussy Three independent buildings (each of which are three levels plus an attic high) containing a total of 36 apartments will be placed perpendicularly to the earth embankment. Although each of

Location Vernier, Geneva Architect Peadar McGrath, Xavier Robert Brief 36 Apartments Date 2014

these three residential blocks is different, they have been similarly conceived, sharing common spaces and a common formal language: terraced housing typology, accessed from the north facade, all flats are dual aspect facing southwest/northeast, blind gable ends, sunken collective gardens facing north and private gardens facing south.

Design strategies to dampen noise Our approach combines architectural elements with vegetation to reduce the impact of noise entering the site. Built elements are only the first step towards reducing noise, it must necessarily be followed by the planting of trees and shrubs carefully chosen according to their position within the overall layout.

As mentioned above, the first strategy to dampen noise is the large embankment of earth on the south-east of the site which becomes an obstacle between the housing blocks and the motorway but also a garden planted with broadleaved trees that will contribute to diluting the flow of sound.

Another strategy against the noise emanating from the motorway is the use of blind gable walls directly facing it. These walls protrude well beyond the plane of the faรงade to become truly protective screens.

The footprint of each block tends to be deeper on the south-eastern side, with protruding stair cores becoming a part of the protective screens.

The faรงades that do have openings, i.e. northeast and south-west, use cantilevered floor slabs to dampen the noise created by airplanes flying over the site. Thus, both the galleries that offer access to each apartment on the north-east faรงades and the balconies facing south-west provide a horizontal screen against aircraft noise. Roof gardens are also crucial in dampening aircraft noise: small sized trees with a wide crown will be planted at roof level, thus becoming an extension of the cantilevers, whilst the mass provided by the depth of the soil bed will also act as an excellent noise absorber.

Private space/collective space The open spaces between housing blocks are envisaged as hard paved little squares, sunny open spaces protected by the retaining wall that will accommodate swings for children and street furniture to relax and have a chat with the neighbours. Adjacent to these squares, a variety of sunken gardens will provide a transition (but also a screen that will guarantee the privacy of the apartments located at ground floor level) between the squares and the close. The galleries providing access to each apartment, as well as the different communal spaces located on each level (laundry, clothes drying, pram storage) are conceived as an extension of these collective gardens. This progression finishes with the strip of private gardens which are linked to the ground floor level apartments, located on the south-west side of each block.

Materials We believe that the scheme would benefit from the use of simple and cheap materials that would minimize maintenance and also blend in to the surrounding environment. A cast in situ reinforced concrete frame will be clad using different materials depending on the orientation of each faรงade. Thus, the gable ends of each building, as well as the earth retaining walls on ground floor level, will be built using dry stone, a technique that lowers the ecological footprint of the project whilst blending perfectly with the proposed vegetation. Lime cement rendered walls at the front and rear elevations will offer an appearance not unlike the neighbouring detached houses located on Chemin de Poussy.

Black powder coated aluminium for railings and window frames, untreated oak timber for sliding shutters. The vaulted roofs that crown each block will have a standing seam zinc roof.

mcgrath@coac.net