Zollikerstrasse – Gigon Guyer Architects

The impressive existing trees on the site of the former villa – a copper beech, a redwood, and a pine tree – influenced the architecture of the replacement buildings in several ways. The trees had an impact on the position, shape, materials, and also the colors of the new structures, calling for a specific architectural reaction to the immediate surroundings.

The new built volume is much larger than the previous building and is divided into two units. An unusually narrow space establishes a visual connection between the shady garden beneath the trees on the street side and the private garden to the west. The narrow interspace is widened and opened up by reflections in the façades’ glazed surfaces, which visually “duplicate” the garden.

Location Zurich, Switzerland

Programme Two houses, 8 owner-occupied apartments, 2 studios, underground parking 14 pitches

Competition 2005, 1st Prize

Planning/Construction 2006–2011

Client Floor Owners' Association Zollikerstrasse, Zurich

Gross Floor Area 2‘896 m2

Team GG Monica Knechtle

Site Management Agora Baumanagement, Zurich

Total Contractor Gross Generalunternehmung AG, Brugg

Landscape Architecture Hager Partner AG, Zurich

Structural Engineer Basler & Hofmann AG, Zurich

Electrical Engineer Ernst Basler + Partner AG, Zurich

Building Services Engineer Ernst Basler + Partner AG, Zurich

Building Physics Engineer IPA, Energieberatung und Bauphysik, Volketswil

Colours with Pierre André Ferrand, Geneva/ La Chaux-de-Fonds

The fulfillment of various specifications regarding noise protection, the spacing required by the building code, and also the protection of the trees’ roots calls for footprints that are not rectangular. However, an orthogonal structure is inscribed within the irregular polygons.

In total, the complex houses eight owner-occupied apartments and one studio, which differ widely in size and character. This is expressed in the number of levels, the ceiling heights, and the respective outdoor spaces. For example, the penthouses have terraces while the apartments on the first and second floors have covered loggias. The three apartments on the ground floor are duplexes, two of which feature living rooms with high ceilings and direct access to a private garden.

Large slabs of in-situ concrete define the private outdoor spaces of the groundfloor apartments. Low yew hedges, interspersed with blooming plants, form loose green divisions between the various garden spaces. The hedges also constitute green boundaries toward the street. Ferns and low shrubs cover the “forest soil” underneath the trees.

The polygonal buildings are covered with dark brown enameled glass panels that reflect the garden space like a kaleidoscope and therefore enhance the presence of the small garden. The mirrored vegetation casts a lively ornamental pattern across the façades, paying homage to the exterior painted decoration on nearby Villa Patumbah.