cosgriff house by christopher polly architect

‘cosgriff house’ by christopher polly architect 

image © brett boardman photography 

a home in australia is given an subtle and transformative renovation by sydney-based architect christopher polly. the project retains its

original envelope as part of its environmental, economic and planning values while a substantial lower ground living volume is sensitively

inserted beneath the original fabric of the home. as the site tends towards the rear, the glazed addition extrudes the existing geometries of

the brick structure and creates a visually light extension that continues wall alignments, gutter levels and enclosing wall heights. the faceted

form is optimized to allow generous daylight to pervade the space and at once posits a interpreted mirror of the extant vernacular tectonic

palette and geometry. 

extrapolation of wall alignments, wall heights and attachment of new work to the original dwelling

image © brett boardman photography 

exterior rear view

image © brett boardman photography 

existing geometries extended and subverted to present an interpreted mirrored slice of the original vernacular form 

image © brett boardman photography 

the roof in particular reframes the home’s relationship to the tree-filled context, with its folds allowing access to north light and easterly views.

the majority of the project is carefully crafted within the retained masonry and hipped roof envelope. vaulted ceilings and skylights carved

within the original roof form expand interior volumes. an airy plan permits a generous stair void that expands to the lower level below, and

upwards to views of the sky. utilities located deep within the semi-subterranean rear of the lower ground enable direct connection of the

living space to the garden and jacaranda tree, while the re-worked ground floor above adds a bathroom, main bedroom and adaptable

bedroom or study area. fenestration placement improves natural light access and promotes passive ventilation, assisted by ceiling fans and

a roof venting system, using stack effect to exhaust trapped heat out of the original roof space.

(left) connections of rear spaces to the outside at night, (right) exterior detail view to the lower ground interior

image © brett boardman photography 

(left): view up to the ceiling forms at the base of the stair

(right): glimpse of connections to the living area below and garden setting and jacaranda beyond

image © brett boardman photography 

(left): folded ceiling arrangement and spatial relationships to the lower level below and upwards to sky and tree views

(right): vaulted ceilings to skylights expand volumes for access to light & sky within the middle of the ground floor

image © brett boardman photography 

(left): lower ground living room view towards the kitchen and semi-subterranean utilities at the rear

image © brett boardman photography 

kitchen interior

image © brett boardman photography

singular expansive living space and connection to the garden and large jacaranda

image © brett boardman photography 

(left): stair hall view towards the rear

(right): upper level bathroom view

image © brett boardman photography 

folded roof beyond the original dwelling incorporating a sole fire-rated northern window along the boundary

image © brett boardman photography 

degrees of privacy offered by external retractable and adjustable venetian blinds

image © brett boardman photography 

floor plan / level 0

floor plan / level -1

section

sections

elevations

elevations

project info: 

location: annandale, sydney, australiaarchitect: christopher polly structural engineer: sda structureshydraulic engineer: acor consultantsbuilder: r.g.gregson constructionsland size: 370 sqmfloor area: 167 sqmcompletion: december 2012

designboom has received this project from our ‘DIY submissions‘ feature, where we welcome our readers to submit their own work for publication.see more project submissions from our readers here.