The Glass House | NSW Environment & Heritage

Culture and heritage


The Glass House

Item details

Name of item: The Glass House
Other name/s: Glasshouse; Bill Lucas House
Type of item: Built
Group/Collection: Residential buildings (private)
Category: House
Location: Lat: -33.801668146867 Long: 151.2196412574
Primary address: 80 The Bulwark, Castlecrag, NSW 2068
Parish: Willoughby
County: Cumberland
Local govt. area: Willoughby
Local Aboriginal Land Council: Metropolitan
Property description
Lot/Volume CodeLot/Volume NumberSection NumberPlan/Folio CodePlan/Folio Number
LOT257 DP19290
All addresses
Street AddressSuburb/townLGAParishCountyType
80 The BulwarkCastlecragWilloughbyWilloughbyCumberlandPrimary Address


Organisation NameOwner CategoryDate Ownership Updated

Statement of significance:

The Glass House is of state significance as a rare example of domestic design by influential architect Bill Lucas, which retains a very high level of integrity. It is historically important in demonstrating the quest by Australian architects of the 1950s and 1960s to design homes to suit a Sydney lifestyle, informal, open to the outdoors, and appreciative of the natural beauty of the rocky harbourside and riverside suburbs in particular. The house both furthers and re-interprets Walter Burley Griffin and Marion Mahoney Griffins' vision for the suburb of Castlecrag. The building is iconic in its stark simplicity. Employing a highly innovative engineering system, the house is light, open and makes barely a mark on the steep, rocky bushland slope. The Glass House has a strong association with its designer Bill Lucas, and also with Ruth Lucas, whose home it was. The couple were important figures in the loose grouping of architects known as the 'Sydney School', and also in the urban conservation movement, and the design and construction of the house embodies many of their concerns as urban conservationists. The extreme minimalism of the house's design, and its unique engineering solution is likely to continue to provide inspiration and design knowledge to architects and other designers.
Date significance updated: 09 Feb 16
Note: The State Heritage Inventory provides information about heritage items listed by local and State government agencies. The State Heritage Inventory is continually being updated by local and State agencies as new information becomes available. Read the OEH copyright and disclaimer.


Designer/Maker: Bill Lucas
Physical description: The Glass House is single storey residence built over a steeply sloping bush site. One corner of the house barely touches the natural sandstone outcrops, the remainder of the building and the decks are suspended over natural vegetation and rock outcrops.

The rectangular plan is divided up into a grid of 12 squares, four feet by three. A timber framework is braced with steel cross bracing: four slender steel posts are the main structural elements, forming the corners of the internal court/lightwell. The steel structure extents to roof level and the floors are hung by steel rods from roof height.

Entry is from a path beside the carport. There is no formal hall, visitors enter straight into the first living room, which was used by Bill and Ruth Lucas for meetings with clients. A wall separates this area from the kitchen and a larger portion of living/dining room.

The living room and kitchen are predominantly glazed, opening onto the front deck and the internal deck and light well. A passage leads from the living room at the entrance, past the laundry/bathroom to the series of bedrooms that run across the southern side of the building. A balcony runs the length of this elevation. Initially the central room on this elevation, like the living/dining room on the northern elevation was not partitioned. The salvaged septic tank that was tiled to form a bath survives. The floor is tiled with slate that has cracked due to movement of the structure. The house moves considerably in the wind.

The outdoor spaces of the house are emphasised. The central two squares are formed by a deck and open well to the sandstone rock below. When the house was completed there were no trees in the light well, but now trees grow up through the centre of the house. The fourth cube along the front is a covered outdoor room, separating the living area from the studio. The studio has a small deck cantilevered over the trees below. This deck is now cut around a tree. A deck also runs across the front (north) and the rear (south) of the house.

The original construction is described in an article in Architecture in Australia, October-December 1957.
The house is suspended on four 3 inch square columns which extend through to the roof. It is of composite construction with steel kept to the minimum for economic reasons being used for tension rods and spacing and joining members. All the timbers are rough-sawn creosoted hardwood inside and out. Wall timbers are restricted to mullions, and posts at 4’ 0” centres and the roof framing to purlins at 4‘ 0” centres on beams at 12 “ centres.

The floor consists of 12’ x 4’ Stramit panels, being masonite faced on hardwood joists at 2’ 0” centres. Stramit is also used for the internal walls. To obviate the difficult on local requirements for masonry all external walls are of glass sheeting. The internal walls are not structural and the arrangement of the bedrooms and living areas can be varied to suit changing family needs.

The roofing is deep corrugated asbestos cement, having no roof battens. Safety mesh is stretched over the purlins and supports a 2 oz white fibre-glass blanket between clear Visqueen and double sided sisalation. This provides high thermal insulation, sound absorption and light reflection qualities, and has a pleasant quilted appearance.
Physical condition and/or
Archaeological potential:
Date condition updated:18 Jan 16
Current use: Domestic dwelling
Former use: Domestic dwelling


Historical notes: The Glass House was designed by Sydney architect Bill Lucas and completed in 1957. It was designed as a home for Lucas to share with his wife, fellow architect Ruth Lucas, and their children, and as a studio for their architectural practice.

Lucas was born in Sydney in 1924. He trained as a Manual Arts Teacher before the war, reflecting his love of, and great skill in, carpentry. After three years' military service 1943-46, he trained at the School of Architecture, University of Sydney, and studied visual art at East Sydney Technical School. He worked with New Zealand firm Hugh Grierson Architects on graduating. By the mid-1950s he had completed a number of domestic and community design projects, chiefly in southern Sydney's bush suburbs. He then joined the Design Group with Tony Moore, Neville Gruzman and Ruth Harvey (his future wife). Lucas helped establish the school of architecture at University of New South Wales and tutored part time there for many years. For the last 22 years of his career he maintained himself on a small war pension and offered his architectural and technical services on an honorary basis only.

Bill and Ruth Lucas were passionate about the relationship between good design, heritage conservation, public education and thriving, equitable communities. Lucas' design projects included education centres, an Aboriginal women's refuge, and furniture and theatre sets. The family moved to Paddington in the early 1960s and joined the campaign to help save the area from slum clearance. Lucas dedicated many years of his life to litigation and lobbying for this cause and contributed to the preservation of Paddington as an area of historic and architectural importance.

Lucas worked to develop architectural processes and prototypes, not merely unique designs, in aid of a vision of ecologically sustainable housing, communities and cities. He was a significant proponent of architectural innovation in NSW, and a highly esteemed member of the loose association of architects that has come to be known as the Sydney School. The architectural approaches and construction systems he developed contributed to the transformation of domestic architecture, in particular, in the post-war decades, and continue to provide inspiration for architects in the new century.

Lucas' Glass House at Castlecrag is esteemed by architects as a seminal example of 'shelter-in-nature' design, a design philosophy developed by members of the Sydney School. These Sydney architects drew on aspects of the modern movement that had grown up in London, New York and parts of the Soviet Union in the first decades of the twentieth century. The movement became influential in Brazil, South Africa, Mexico, Japan, and to some extent Australia during the 1920s and 1930s. The influence of the movement in Australia was partly through Walter Burley Griffin's designs, which referenced the architecture of Frank Lloyd Wright, a key proponent of the movement in America.

After the war, the movement diversified greatly. Architects in Australia and elsewhere placed a strong emphasis on responding to local natural and cultural environments, and this led to many schools of design with regionally distinctive characteristics. In Australia, the post-war years saw renewed discussion about possibilities for a specifically Australian tradition and cultural identity. Modernism, seeming in many ways to be an international language, became an important part of this conversation. The Australian modern movement got underway in earnest from the late 1940s as Harry Seidler's uncompromising dwellings of the late 1940s transplanted the International Style into the Sydney landscape.

The Sydney School of the 1950s and 1960s strove to develop a domestic architecture to suit this city, drawing on modernism and brutalism as well as the 'International Style'. Promulgating this philosophy, the Design Group, to which Lucas belonged, aimed to design 'cutting edge buildings that were Australian, for Australians, using only Australian plant material in the gardens'. These architects' quest was partly a response to the post-war boom in suburban development, spreading a landscape of rows of fibro and tile boxes across the Cumberland Plain, in a way that seemed to make no concession to the Australian climate or the local landscape. The efforts of the Sydney School resulted in a smattering of houses, particularly in Sydney's leafy, rugged northern suburbs, but also groups of project homes like those built by Pettit and Sevitt in Carlingford and elsewhere. Jennifer Taylor in her retrospective on the Sydney School, first published in 1972, An Australian Identity: houses for Sydney 1953-63, felt that these homes did achieve their aim, she wrote: 'The climate was respected, the potential of local materials recognized, and the inherent merit of indigenous flora and local topography exploited. The result has been an Australian house.'

Comparisons can be made with a number of other residences designed by other architects associated with the adaption of modernist principles to domestic buildings in Sydney, including Jack House, Wahroonga, designed by Russell Jack (1957); Lyons house, Dolan's Bay, designed by Robin Boyd (1966); The Audette House, Castlecrag, designed by Peter Muller in 1953; and Simpson-Lee House, Wahroonga designed by Arthur Baldwinson (1957). Like these other houses, the Glass House features a flowing open plan interior separated if at all by lightweight partitions; an innovative construction method aimed at integrating the home with the natural vegetation, views, light and other aspects of the environment; and a minimalist aesthetic featuring glass and timber and emphasising the relationship of interior and exterior.

Lucas selected a steep and rocky site, and developed a construction system that could perch amongst the rocks and suspend the living spaces between the trees with only minimal disturbance - four slender steel columns extending up through the house, with the floors suspended from them. As a result, the four slender support columns and an entry ramp are the only points which touch the ground. Lucas felt that having chosen a site, people should adapt their living to it, rather than building homes in way that would render it unrecognisable. The flora on the site has continued to grow, and trees now grow up through the central light well.

Lucas observed that housing is often 'defensive', aimed at protecting the inhabitants against other people and the environment. He found this a sign of the 'basic insecurity' of Western life, and he took care to orientate the Glass House towards the outside and maintain openness towards the environment.

The Glass House was also designed with economy in mind, as a model for accessible housing, employing a modular design, and standard, but chemical free, low cost off-the-shelf industrial products and second hand building materials. Like other residential buildings designed by architects of the 'Sydney School', Lucas' Glass House makes use of natural, rough, self-finished materials. The house's surfaces are not painted or clad, and the structure of the building is readily discerned with the frame only minimally closed-in using glass on many of the surfaces. As Lucas noted in the introduction to "Architecture into Millennium III", he selected materials that can be utilized to satisfy needs with as little effort as possible, self-finished, maintenance free, that improve with wear, that merge with natural surroundings and that provide an appropriate background for living. I prefer the 'construction' to provide the 'finish'. This framework represents a highly unusual way of building a house, ties are used to create the tension necessary to suspend the building from its frame, like a light aircraft.

The Glass House, at 80 The Bulwark, Castlecrag is part of Walter Burley Griffin and Marion Mahony Griffin's 1920s subdivision. The couple had arrived in Australia in 1914, having won the competition for the design of the new national capital, Canberra. In 1920 Griffin formed the Greater Sydney Development Association Ltd to build residential estates on three picturesque headlands on Sydney's Middle Harbour. Castlecrag was the first of these estates, begun in 1921. Griffin intended the estate to retain and complement the character of the landscape, and to provide a model for a way of life that would harmonise with the natural environment. He set out a street pattern that followed the contours of the rugged headland, and interspersed public reserves and connecting pathways with the house lots, intending public and private to merge unbounded by property fences. Griffin designed and built several distinctive houses of rock and concrete to demonstrate the style of house that lot-purchasers would be required to build. He and Marion moved from Melbourne to Castlecrag in 1924 and Marion took the role of a community leader at Castlecrag, organizing a variety of cultural activities from ballet classes to classical drama, staged in a rock-gully adapted to serve as an amphitheatre. The Castlecrag Progress Association, the Castlecrag Conservation Society, the Castlecrag Playreading Group, the Haven Theatre Committee and the Walter Burley Griffin Society continue the community spirit initiated and inspired by the Griffins. While the estate nurtured a small community, it did not gain further momentum at this stage: by 1937 only nineteen houses, sixteen of them designed by Griffin, had been built on the 340 lots. The development of Castle Cove and Middle Cove according to the Griffins' vision was also prevented by financial constraints, and then largely deferred until the post-war years.

The Glass House was one of three adjoining houses designed by Lucas on The Bulwark. Lucas was an admirer of the Griffins' work, and committed to their vision of Castlecrag. The house is a reinterpretation of the restrictive covenants imposed by the Griffins on these land parcels; the design of the house took a very different direction to Walter Burley Griffin's own designs, being light and open in comparison to Griffin's quite solid, monumental buildings. Castlecrag attracted a number of other architects post-war, experimenting with design philosophies similar to those developed by Lucas. They designed homes including Peter Muller's Audette House and the home of Hugh and Eva Buhrich on Edinburgh Road, and the house designed for photographer Max Dupain by Arthur Baldwinson on The Scarp. The Australian Institute of Architects and Local Government recognise a number of these properties for their heritage values.

For the architectural community, the Glass House remains a landmark building. Its extreme minimalism and its sensitive relationship to the bushland site, continue to provide inspiration. Former partner Neville Gruzman sees it as one of Australia's most important houses. In his obituary for Lucas, Gruzman describes the Glass House as extraordinary in a deceptively simple way: 'if ever a house touched the ground lightly, it was this one this house threw aside every precept of house design and construction: it featured minimal cost, minimal structure, minimal energy use and was beautiful'. Similarly, Peter Moffit, in his obituary for Lucas in the Sydney Morning Herald found the house striking in its simplicity and for its lightness on the steeply sloping bush site, 'audaciously simple in its concept, it stands on tiptoes amongst the boulders and the ferns on four slender steel posts - the house appears to barely touch the ground, suspended amongst the trees'.

Docomomo International recognises the Glass House as a seminal example of the 'shelter-in-nature' minimalist compositions constructed in northern Sydney post World War II and compares it with other exceptional modern movement buildings internationally, including Philippe Chareau's Maison de Verre in Paris (c1929), Mies Van de Rohe's Barcelona Pavilion (c. 1929), and Charles Eames 1949 house in Santa Monica. William J. R. Curtis, author of Modern Architecture since 1900, singles out the Glass House as a remarkable example of an Australian adaptation of modernist principles, being 'so understated that it virtually disappeared into its wooded setting' and emphasising a casual lightness, simplicity and openness that articulated the Australian way of life as it was beginning to be understood at that time.

Historic themes

Australian theme (abbrev)New South Wales themeLocal theme
4. Settlement-Building settlements, towns and cities Accommodation-Activities associated with the provision of accommodation, and particular types of accommodation – does not include architectural styles – use the theme of Creative Endeavour for such activities. Residences-
8. Culture-Developing cultural institutions and ways of life Creative endeavour-Activities associated with the production and performance of literary, artistic, architectural and other imaginative, interpretive or inventive works; and/or associated with the production and expression of cultural phenomena; and/or environments that have inspired such creative activities. Architectural styles and periods - mid 20th century modernism-

Assessment of significance

SHR Criteria a)
[Historical significance]
The Glass House is an important place in the cultural and architectural history of NSW. It embodies a quest by Australian architects of the 1950s and 1960s to design homes to suit a Sydney lifestyle, informal, open to the outdoors, and appreciative of the natural beauty of the rocky harbourside and riverside suburbs in particular. In turn, this quest was part of, and important in, a wider movement to articulate a distinctive Australian identity in a newly globalised, post-war world. It is likely that the house has helped to shape Australian expectations of the amenity of suburban living, particularly in subdivisions carved out of the steep, bushland gullies of Sydney in the 1960s and 1970s.
SHR Criteria b)
[Associative significance]
The Glass House has a strong association with its designer Bill Lucas, and also with Ruth Lucas, whose home it was. The couple were important figures in the loose grouping of architects known as the 'Sydney School'. Bill Lucas in particular made a significant contribution to the modern movement in NSW. His designs, in particular The Glass House, are highly esteemed by other architects, and have influenced the direction of domestic design in NSW. Bill and Ruth Lucas both connected the values of modern architecture and thoughtful design with philosophies of the public good: public education, heritage conservation and the arts more generally. The Glass House, in employing recycled and chemical free materials, and treading lightly on the site, demonstrates many of their concerns as urban conservationists.
SHR Criteria c)
[Aesthetic significance]
The Glass House has aesthetic and technical significance for NSW. The building is iconic in its stark simplicity; light, open and making barely a mark on the steep, rocky bushland slope. The extreme minimalism of the house's design, construction and visual impact has provided inspiration for many architects in the decades since its construction. The Glass House is of technical significance for its unique engineering solution, which enabled a minimal footprint and the retention of the sandstone outcrops, eucalypts and ferns below, and for the conscious use, by the Lucas' of Australian made building materials. The house enhances the local architectural landscape by re-interpreting the Griffin's garden suburb concept for Castlecrag.
SHR Criteria d)
[Social significance]
The Glass House is of state heritage significance for its importance to architects and the wider community who appreciate modern design and architecture. The house has been recognised by prominent professional architectural bodies (including DOCOMOMO Australia and the NSW Chapter of the Australian Institute of Architects) and continues to be visited and written about, and it continues to inspire innovative design amongst the architectural community of NSW.
SHR Criteria e)
[Research potential]
The Glass House is of state heritage significance for its potential to yield information about Lucas' highly innovative construction systems and their durability. The system was intended to be a prototype and embodies knowledge which will continue to be of value to architects and engineers.
SHR Criteria f)
The Glass House is one of a very few surviving domestic buildings designed by Bill Lucas. It has rarity value at a state level as a virtually unaltered modernist residence embodying the ‘shelter-in-nature’ principles of this highly influential architect, and employing a unique design and construction method.
SHR Criteria g)
The Glass House is a carefully handled example of modular design, using standard, but chemical free, low cost off-the-shelf industrial products and second hand building material. The building can demonstrate the local application of Modern Movement concerns with the connection between internal and external space, the use of flexible internal space, moveable partitions and outdoor living areas, and has the capacity to represent the philosophies and physical characteristics of 'Sydney School' residences in NSW.
Integrity/Intactness: Good
Assessment criteria: Items are assessed against the PDF State Heritage Register (SHR) Criteria to determine the level of significance. Refer to the Listings below for the level of statutory protection.


Heritage ListingListing TitleListing NumberGazette DateGazette NumberGazette Page
Heritage Act - State Heritage Register 0198121 Oct 16 842812

References, internet links & images

TypeAuthorYearTitleInternet Links
WrittenDoCoMoMo International working party for documentation and conservation of buildings, sites and neighbourhoods of the modern movement2003Members Update 2003
WrittenJennifer Taylor1984An Australian Identity: Houses for Sydney 1953-1963
WrittenNeville Gruzman2001'Bright thinker persued his utopian vision' in Sydney Morning Herald (1 November 2001)
WrittenPeter Myers2002'Bill Lucas 1924-2001' in Architecture Australia, November-December 2002
WrittenW J R Curtis1982Modern Architecture Since 1900

Note: internet links may be to web pages, documents or images.

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Data source

The information for this entry comes from the following source:
Name: Heritage Office
Database number: 5056593
File number: EF15/16844

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