Durbach Block Jaggers visualise a ‘column’ tower to adorn Sydney’s skyline

Coming alive, seemingly from the pages of a 40s Batman comic book, the Pencil Tower Hotel is New South Wales-based architecture studio Durbach Block Jaggers’ winning entry for the City of Sydney Design Excellence Competition, and an improbably narrow skyscraper proposal, no wider than your own living room. I am particularly reminded of production designer Anton Furst’s work in creating the Gotham of Tim Burton’s 1989 classic comic book caper, Batman, for which he took on a unique design aesthetic: a combination of the principle of the gothic, the material of the brutalist, and the clean lines of the modernist style, to create an architecture that was literally otherworldly, creating layers that weren’t reflective of any particular time period. Rooted mostly in fantasy, Furst’s Academy Award winning design made Gotham a rare reverie vision and an isolated urban occurrence. While the vision for the Pencil Tower Hotel qualifies to be placed inconspicuously within the skyline of Burton’s and Furst’s Gotham, the project here is touted to be a reality, making its structural and spatial considerations an interesting academic study.

The entire narrow vertical extrusion of the Pencil Tower is proposed to stand on a multi-storey podium, and while the majority of the tower’s ‘functional’ body, rising above, lies relatively unadorned, mimicking the distinct yet now widely adopted geometrical facades of skyscrapers in metros everywhere, the podium is aptly “dressed” as the public edifice of the building. It reflects the design and character of its heritage neighbours, using the language of a grand arch in brickwork that encloses a large keyhole window, through which one may view a three-storey urban room. Visible from the street and an intended part of the public edifice of the building, the urban room houses a lobby, cafés and lounges across different levels. At the top of the podium, the building mass offsets significantly to create a walled courtyard garden overlooking the street.

The form of the narrowly cuboidal tower itself is an iteration of the classic column, simulating its compression and extension through a continuous abstraction of its base, shaft and capital. While the podium is the base, the shaft is manifested in the immensely striated façade. Beginning with compressed horizontal screening, flushed with the outside frame of the confined body of the tower, the façade eventually gives way to exaggerated verticals towards the top. While the horizontal striations reflect the height of the slab, the handrails at the floor landing levels, and the door head heights in the interiors of the buildings, the vertical striations reflect the spatial programming of typical floors, with compact hotel rooms on each floor, cited to be closer to plane and train compartments as opposed to conventional hotel rooms by the architects. With typically six rooms per floor, the hotel will also have large backhouse areas in the basement and podium, with dedicated goods and services lift and cleaning/store room adjacent on every third hotel floor.

The capital of this “column” emulating building is an elaborately designed “flying balcony”, a rooftop sundeck with an inward curving soffit. While the floor houses other in-house facilities for its resident guests including a pool and a “hammam” spa, the soffit underneath is lined with bright, reflective tiles, visible from the street below and in the distance, from the city as well. Each of the designated rooms on the floors below is designed to have a keyhole shaped orifice that gathers light from the street, rear court, or internal voids, tiled to reflect light and colours into rooms.

As can be expected, the primary challenge for the building comes in the form of structural considerations. Given the narrow frontage and the slenderness of the structure, while the first six levels of the podium can be built using conventional methods: flat RCC slabs supported on walls and columns, crane access above level six becomes a major challenge. To overcome that, the structural design envisions permanent steel slab forms and permanent formwork for walls that can be handled and assembled without a crane. The floors and walls would then be reinforced following detailed 3D structural analysis. Interestingly enough, upon completion, the Pencil Tower Hotel would be only 0.3m (1 foot) narrower and 12m higher than the thinnest building in Australia in Melbourne, the Phoenix Tower in Flinders Street, instating Sydney with the title. This improbable compound of buildings is charmingly dubbed the ‘sky scratcher’ category, comprising buildings that are too narrow to really qualify as a skyscraper.

Project Details

Name: Pencil Tower Hotel
Location: 410 Pitt Street, Sydney, Australia
Architects: Durbach Block Jaggers
Client: Tricon Management Group Pty Ltd
Site Area: 345m sq
FSR: Max allowable 15.4:1, achieved 14.33:1
Total Built Up: 4,950m sq
Height: 32 storeys / 106m
Width: 6.4m wide Pitt Street frontage
Program: Three storey urban room housing lobby, cafe & lounge fronting Pitt Street, 173 hotel suites, Rooftop hammam, pool & spa
Structural Engineer: Richard Green Consulting/TTW