Disturbing news report from the Sydney Morning Herald about the fitout of Harry Seidler’s heritage listed Edmund Barton building on Kings Avenue. It seems like the consultation with Seidler and Associates promised by the owners of the building, Stocklands, isn’t working out so well. The Federal Government spent over $40 million refitting Anzac Park West for the Australian Federal Police but found it was too small, so it sits empty. The AFP now plans to spend $115 million fitting out the heritage listed Edmund Barton building.

Penelope Seidler and Peter Hirst (Seidler and Associates) have written to the Parliamentary Public Works Committee seeking more information about the protection of the building’s heritage values, voicing their concern about how the proposed security measures and changes to the ground level will affect the external appearance of the building. Seidler and Associates were initially advised by Stocklands that they would cooperate to ensure that the integrity and heritage values of the building were not compromised.

We have made various suggestions on preliminary designs for this work but have not seen any drawings for some time.

Why is it important? The post-war international Edmund Barton building is one of Seidler’s most important public buildings and arguably his best non-tower office block. The contrast between rectilinear and curved forms was an important and recurring theme throughout Seidler’s career and is fundamental to the idea of this building. The open ground floor accommodates quadrant shaped glass lobbies for the three entries, while the circular cores form the corner of the building and conceal the vertical services.

To viewers in the offices above, the quadrant shaped conference hall expresses its theatre seating and acoustic form and the cafeteria shows its long span shell-shaped roof elements. This theme of visual tension and contrast between the rectilinear and curved elements is reinforced by the courtyard paving pattern and in the two sculptures by Norman Carlberg, one in each courtyard. A fountain had the same effect, but it was filled in some years ago and replaced by landscaping. Underpinning this is the clearly expressed resolution of the two major parts of the structural system: 22.5m I-shaped spandrel beams and 15.8m T-beams of the spanning floor systems.

The building is also a rare example of Seidler’s work in Canberra, being the most significant of the two intact Seidler office buildings here. A quick overview of Seidler’s Canberra work:

• 12 Yapunyah Street O’Connor (1956): demolished
• Garran Group Housing (1968): demolished in the late 1990s
• 11 Northcote Crescent, Deakin (1951-52): extended twice, no heritage protection
• Canberra South Bowling Club (1959): extensively modified
• Campbell Group Housing (1964): intact, but no heritage protection
• Ethos House (1970): intact
• Macgregor townhouses (1980): intact
• Lakeview townhouses in Yarralumla (1982): intact
• The Edmund Barton building (1973): intact—for now

I think that statements being made by the AFP about the nature of the modifications (reported in the Sydney Morning Herald) are of concern.

Mr Keelty told the committee security measures would include a ‘transparent perimeter barrier’ to control pedestrian access to internal courtyards and bollards to stop unauthorised vehicles from approaching the building. Federal police executives said heritage values would be enhanced by reintroducing some of Mr Seidler’s original concepts by making the internal courtyards more welcoming for staff.

The idea that it was Seidler’s intention to close off the courtyards so as to make them more accessible for staff simply doesn’t ring true. These courtyards were designed as spaces for staff and pedestrians, with the fountain (long since filled in), works of public art, a cafeteria and a theatrette. The building bears all the hallmarks of a Seidler building—maximizing public open space at the ground floor. The sculptures and the buildings in the courtyard are positioned to control the open areas and make them more intelligible to the pedestrian as well as office workers who look down into the courtyards from the windows above. Closing this courtyard off to the public contradicts this aim and will not enhance the heritage values of the building.

A related concern, but thus far not mentioned, is future public access to the works of art. Closing the area off for security reasons and restricting access will deprive the city of two important works of public art by Norman Carlberg, the internationally acclaimed American sculptor who worked in the modular constructivist style and studied under Joseph Albers at Yale in the late 1950s. Black Widow is the free standing black painted steel form standing 4.8m high in the west courtyard. Concrete Form is the 7.3m high precast concrete sculpture in the east courtyard. These two important works were installed in 1975.

While unrestricted access to public art can be a grey area when such works are located inside commercial buildings and schools, for example, I would be interested to see some kind of statement about how these sculptures will remain accessible to the public once and if these alterations are made.

Over at my Flickr photostream I’ve put together an image set called Canberra’s Top Twenty—a list of Canberra’s most important modernist houses. The images are geo-tagged, and I’ve created a KML file for you to play in Google Earth.

While some may argue that the list is arbitrary, it is substantially based on significance according to the Royal Australian Institute of Architect’s Register of Significant Twentieth Century Architecture and nomination to or listing on the ACT Heritage Register. It is open to debate, of course, and a colleague has already taken me to task for initially including Robin Boyd’s last Canberra house at 12 Marawa Place ahead of Noel Potter’s house at 3 Arkana Street, Yarralumla.

Looking at the tour, it’s interesting to see the geographic spread of the houses around Canberra. While many are located in the inner south and date from the 1930s to the 1960s—modernism’s golden age if you like—there are examples in some of the newer suburbs, or areas developed since the late 1960s. It finishes around the mid 1970s, in line with the general feeling that heritage has to be older than 30 years to qualify as such.

It also highlights how few of Canberra’s houses are of heritage significance. When one talks about heritage listing (and more importantly) preserving houses, it’s not as though we’re talking about locking away vast tracts of valuable land from developers. Of Canberra’s total housing stock we’re only talking about protecting and conserving a tiny handful of houses from the mid twentieth century. And if we’re unable to do that it reflects badly on us as a community.

So, download this KML file and view Canberra’s Top Twenty in Google Earth. Let me know what you think.

As I drive or ride over Commonwealth Avenue Bridge, I often think of Sir Robert Menzies—no, really. Menzies thought the Bridge was the ‘finest building in the National Capital’. Opened to traffic in November 1963 over the yet to be filled lake, the bridge was and is regarded as a lovely example of form and function working together. It remains the principal entry point to Canberra’s National Area. How did something we may now take for granted and not give a moment’s thought come about?

In 1957, British town planner Sir William Holford was invited by Menzies to review the Griffin plan, which had basically languished since Canberra was formally named capital on 12 March 1913. In his report, Observations on the Future Development of Canberra, Holford pushed Griffin’s idea of incorporating a lake to unite the two halves of Canberra. His view was that Canberra could either remain divided with the flood plain of the Molonglo as an ‘open wedge’ between the federal town on the south bank and a municipality on the north—or it could become a unified city. He didn’t shirk the issue—he was convinced the NCDC should opt for the latter option:

Real quality and imagination in the design of three features of the new city – the Commonwealth Avenue Bridge, the permanent Parliament House, and the Lakes, would lift Canberra at once into the ranks of the significant capital cities of the world.

The development of Lake Burley Griffin—one of the key features of Griffin’s plan for the capital—was perhaps the NCDC’s key undertaking during the 1960s. The Scrivener Dam was completed in September 1963 and began filling to form the lake. The decision to create the lake meant that new bridges had to be built to replace existing timber structures across the Molonglo River. Intriguingly, on some early maps showing Griffin’s plan, there are three bridges across the lake—Commonwealth and Kings Avenue bridges and an additional one spanning the lake from Black Mountain Peninsula to the area near the bottom of Novar Street in Yarralumla. Obviously, this was never built. So the four lane Kings Avenue Bridge was opened on 10 March 1962, with a motorcade led by Prime Minister Menzies.

The Commonwealth Avenue Bridge needed to accommodate six lanes of traffic on two structures, with pedestrian access cantilevered out from each. Approaches to each side needed to pass under Commonwealth Avenue. The design requirement was for a sleek, horizontal structure with a reasonably long span resting on slender piers—very modern. This low profile aesthetic would make sure there was visual continuity between the central and west basin of the proposed lake. The final design was submitted by G. Maunsell and Partners and William Holford and Partners, while Hornibrook Pty Ltd would be the construction company.

Each bridge was designed as a single geometrical arc formed by a continuous pre-stressed concrete box girder 2.7m thick and over 300 metres long. The roadway width on each bridge was over 11 metres and an asphalt/concrete surface for the road was designed to be placed on the top element of the box girder members.

Work commenced on the bridge in March 1961. At the peak of building, up to 500 men would gather on the flood plain to work—uprooting trees, removing soil, cottages and dismantling the timber truss bridge at Commonwealth Avenue. The construction required extremely close attention to detail and high quality materials for the pre-stressed concrete. After extensive testing it was discovered that all of the required materials were available locally: high quality aggregates, the right rock and various types of sand. Extensive falseworks were required for the initial support of the bridge superstructure and for the degree of accuracy required in placing the pre-cast concrete bridge segments. Critically, no floods were experienced during construction, which would have hampered these efforts with the timberwork.

The Bridge incorporated several design features that were new to major bridges in Australia. The superstructure comprised the first post-tensioned concrete multi-webbed torsion box made of jointed pre-cast segments. The one hundred segments were stressed together in one operation over the full length of deck by 320 metre long external tendons. To a non-engineer, this still seems like a remarkable feat. For each bridge 102 reinforced concrete box segments 3 metres long and weighing 45 tons were cast on site and after curing were carefully placed by gantry on the timber falseworks. The 3 inch wide gap between each segment was filled with fine concrete to make a continuous box girder over 300 metres long. This was post-tensioned by external high tensile steel cables. After final checking for stresses the cables were encased in concrete to prevent corrosion.

Following on from the successful example of Kings Avenue Bridge, lighting for the Commonwealth Avenue Bridge was achieved by fitting a line of fluorescent tubes in each outer handrail. This integrated lighting marked the edge of the carriageway and provided illumination for the footpath and an impressive night-time display of the bridge structure, seen in countless postcards since. The resulting absence of post-top lighting on the bridge further enhanced the sleek appearance of the structure and didn’t break the view of the lake and the Parliamentary Zone.

Commonwealth Avenue was more than just a link in the city’s road network: it also performed an important role in Canberra’s developing sewerage system. Who knew? The original intercepting sewer to the north had been built in an inverted siphon under the Molonglo River near Commonwealth Avenue. The proposed lake raised concerns that the tunnel might collapse during flood, so the decision was taken to incorporate sewer mains within the superstructure of the bridge itself: 500 millimetre inside the eastern bridge and 450 millimetre on the western bridge. A vent was incorporated in the south-east decorative pylon and a pumping station built next to the northern approach of the eastern bridge.

Ever noticed the old stones in the supporting embankments? When London’s historic Waterloo Bridge was demolished in 1936 some of the large, flat stones from the 119 year old structure were donated to the Commonwealth Government. The stones were stored in quarries around Canberra for decades and eventually used in the supporting embankment under Commonwealth Avenue Bridge.

The Bridge is a twin structure, with separate parallel carriageways. The bridge structures are of 5 spans totalling 310 metres, of fully continuous prestressed design. It has a higher camber than Kings Avenue Bridge, a design feature to allow for yachts to sail beneath. The end pylons give added importance to the bridge as the main route to Parliament House. To provide an exit and entry clover leaf layout, separate structures are built on the main bridge’s south approaches, totalling 49 metres each, in 4 approximately equal spans.

The Bridge is like an important piece in a puzzle. As we can see now, the Central Basin of the lake is the centrepiece of the National Area in the immediate foreground of the National Area, and unites the wider city-scape and public spaces on its foreshores in which are now set major national buildings. The Bridge brings the natural beauty of the mountains and adjacent hills into focus and visually unites them with this created setting for our public buildings. It provides marvellous aesthetic qualities and is a major feature of Canberra’s viewpoints at Black Mountain, Mount Ainslie and Red Hill lookouts.

A large backlog of nominations to the ACT Heritage Register has been building up over the past decade. During that time the RAIA has nominated a number of important houses and buildings to the ACT Interim Heritage Places Register. Unfortunately, few of these have ended up as actual heritage listings.

Some good news though—the ACT Heritage Unit has begun to shift the backlog and a number of provisional nominations to the ACT Heritage Register have been made in recent months, along with some notable rejections (more about these below). Following a period for public comment, these provisional nominations will be put before the ACT Heritage Council, who will decide whether to register these places under the Heritage Act 2004.

The following houses have been provisionally nominated:

• 145 Mugga Way, Red Hill
• 24 Arthur Circle, Forrest
• 19 Downes Pl, Hughes
• 13 Furphy Pl, Garran
• 13 Canterbury Cres, Deakin
• 1 Astley Place, Garran
• 42, 44, 46 Vasey Cres, Campbell
• 4 Cobby St, Campbell
• 12 Marawa Pl, Aranda
• 16 Ryrie St, Campbell

These places have been rejected for listing, due to their not meeting the criteria for significance set out in the Heritage Act:

• 15 Furphy Place, Garran
• 24 Cobby Street, Campbell
• 51 Tasmania Circle, Forrest
• 51 Melbourne Avenue, Forrest
• 14 Jansz Crescent, Griffith

Two of these rejections are disturbing, with inappropriate and insensitive additions greatly reducing the significance of 15 Furphy Place and 24 Cobby Street.

Let’s look at 24 Cobby Street, Campbell, designed by Sir Roy Grounds in 1965. The house is a late example of a combination of two styles: the post-war international style and, to a lesser extent, the post-war Melbourne regional style. The house is one of a small number of detached houses that Grounds designed in Canberra and contained elements of his work that combine rational and economic planning with the use of natural materials and his interest in geometric forms, seen at its strongest in the Australian Academy of Science (1959) in Canberra.

The RAIA nominated this house to the ACT Interim Heritage Places Register approximately ten years ago, with a detailed citation researched and prepared by the RAIA ACT Chapter RSTCA Committee. Significant fabric was removed and extensive construction was allowed to occur to the front of the place, as well as in front of the existing building line—all contrary to existing heritage requirements at the time. The cultural and heritage significance of this place was allowed to be diminished through the planning process to the extent that the house is no longer considered worthy of heritage listing.

That’s incredibly disappointing.