Construction

The Baha'i House of Worship is a unique architectural development.

Its nine sides and nine entrances symbolically represent the unity of the human race under the one God, irrespective of ethnic and religious background, according to the teachings of the Baha'i Faith. It is one of only seven such structures in the world, the others being located in Germany, India, Panama, Uganda, the United States and Western Samoa.

The design and construction of the House of Worship were approved in 1957. Sydney architect John Brogan was given the task of developing the design of the Temple from initial concept sketches that envisaged an elegant concrete structure surmounted by a dome, capable of accommodating up to six hundred people, set high in a natural bushland setting of 38 hectares on Sydney's northern outskirts, overlooking the Pacific Ocean.

The rotunda of the auditorium beneath the dome was to take the form of a regular nonagon, encircled by an inner ambulatory which in turn would be encircled by an outer ambulatory serving as an entrance to the auditorium and connecting the nine entrances to the Temple from the exterior. At each of the nine corners would be stairways providing access to the upper level galleries and the basement beneath the auditorium.

Since the structure would involve repetitious construction (the building elements being symmetrical about an axis point), the framework was designed to be reused from one location to the next, the concrete being poured under gravity, from a concrete mixer located on a central tower, to the walls and floors. This proved to save considerable time and cost by avoiding the need to cease work to relocate plant and equipment for each new pour. Pouring of the walls and floors was estimated to take up to nine months after which the construction of the dome would commence.

The building itself was to make use of innovative construction techniques never before employed in Australia. This included a white quartz aggregate facing to the large exterior wall faces, set in a special white cement. A special additive to the concrete mix was to be used to delay setting of the surface of the contrete walls, to allow brushing away of cement to expose the quartz aggregates. Not only would this provide a striking finish to the building, but it would also provide a durable and low maintenance surface.

Another groundbreaking technique was the erection of a prefabricated lantern structure atop the completed dome. This involved the use of a helicopter to raise the lantern into position, the first time such a technique was used in Australian building construction. It attracted extensive media reporting at the time.

The interior wall and column surfaces of the Temple utilised a vermiculite sprayed concrete finish with a colour additive. This provided an inexpensive and durable textured surface finish.

To save time in construction, and in travel time for the construction crew to and from the site, many of the building elements were to be prefabricated off site. This included door and window frames, the segmented main arches with decorative concrete panels to the nine entrances, and the small domes over the stairwells. An added advantage of prefabrication of these elements was the ability to achieve higher levels of quality and tolerances in a controlled workshop environment.

Construction commenced in April 1957 and by January 1958 the outer brick retaining wall foundations were completed. Construction of the foundation walls and a quarter of the Temple floor was completed by 21 March 1958, after which the erection of the central tower commenced, supported by nine 20-metre high slender steel columns. By November 1958 the nine facings of the lower walls were erected, and the gallery roof was scheduled to be completed by January 1959.

The dome ribs were formed of pre-stressed concrete, poured on the ground and lifted into position to provide support for scaffolding and formwork for the dome sections. These sections, a mere eight centimetres thick, were formed by spraying concrete onto the formwork and over the steel reinforcing bars. At the base of the dome, a hollow ring girder was constructed to act as a reservoir for roof water collection.

On completion of the main structure and dome, a plate bearing an inscription in Arabic, reading "To the Glory of the All Glorious", was hoisted into position beneath the lantern to the centre of the dome inside the auditorium.

Construction of the Temple took more than four years to complete, at an approximate cost of 150,000 pounds. On 17 September 1961 it was formally dedicated and opened to the public.

Today this magnificent edifice, standing some 38 metres in height, with a diameter of around 30 metres, has become a highly visible landmark of Sydney's northern beaches.