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The Archibald - Gosford

Project Overview
The development consists of two high-rise towers built upon a shared multi-level podium.

Total Height: 28 storeys (East Tower) and 27 storeys (West Tower).
Composition: The structure consists of 2 towers with common podium, 28 storey high rises with roof and 1 basement level,130 hotel rooms, 323 residential apartments, Ground floor Pub + Hotel Lobby + Retail, Hotel foyer at Level 01, and a striking 960 m² rooftop “Skybar.”
Key Stakeholders: Developed and built by ALAND; Architecture by Dickson Rothschild (Concept) and Place Studio (Delivery); Structural Engineering by JSBC Consulting.

Architectural Form
The architectural language is a tribute to the local geography, specifically the sailing culture of the nearby Brisbane Water.

Form & Massing: The towers feature striking white, sail-like curves. This “coastal luxury” aesthetic is achieved through articulated precast concrete and energy-efficient glazing.
Facade Treatment: A monochrome motif is softened by vertical greenery and external plantings integrated into the balcony systems. The use of floor-to-ceiling windows, maximizes natural light and views.
Public Domain Integration: The ground floor acts as a “vertical village,” featuring a large pub and retail precinct designed to draw pedestrian traffic from Donnison and Mann Streets, integrating the private development with Gosford’s urban fabric.

Engineering The Archibald: Our Structural Solutions

As the lead consulting structural engineers for The Archibald in Gosford, NSW, JSBC Consulting was tasked with delivering the structural framework for this landmark twin-tower development. From navigating complex waterfront ground conditions to optimizing high-rise load paths, our team engineered practical, high-performance solutions to bring this architectural vision to life.

Below is a snapshot of some of our notable structural engineering solutions on this flagship project:

1. Overcoming Waterfront Challenges: Specialized Foundation Design The site’s proximity to Brisbane Water and a high water table necessitated a highly specialized foundation approach. Rather than relying on a standard basement design, JSBC Consulting engineered a Raft Slab on Piles to actively address significant hydrostatic (uplift) pressure and poor soil stability.

Hydrostatic Resistance: We designed a reinforced concrete raft—reaching thicknesses up to 1.5 meters thick under cores —to provide the necessary dead weight to effectively counter buoyancy.
Tension Piling: We engineered deep piles designed to work in tension. These piles effectively “pin” the raft to the underlying Hawkesbury sandstone bedrock, preventing the massive structure from lifting as groundwater levels press upwards.

2. Bridging the Gap: The Post-Tensioned Transfer Slab At the heart of The Archibald’s structural integrity lies a masterfully engineered transfer slab, designed by our team to bridge the gap between two entirely distinct architectural layouts: the residential towers above and the open commercial and car parking zones below.

The Structural “Bridge”: Our engineering team implemented a high-strength, post-tensioned transfer level. This massive horizontal element captures the immense vertical loads descending from the 28-storey residential towers and redistributes them seamlessly into the podium’s reinforced column network.

Our team has extensive Tier 1 background experience

we provide innovative
structural solutions

One City Square Parramatta

Engineering a “City Within a City”: The Structural Story of One City Square Parramatta

As the geographical centre of Sydney shifts westward, Parramatta is undergoing a historic transformation. At the southern edge of the CBD—an area once dominated by car dealerships and known as ‘Auto Alley’—a visionary masterplanned precinct is rising.

Designed by AJ+C Architects in collaboration with Turner and Oculus, Gateway Parramatta (part of the One City Square precinct by JQZ) encompasses over 62,800m² of Gross Floor Area. As the lead consulting structural engineers for the project, JSBC Consulting was tasked with designing the framework for this massive, multi-sector precinct.

Here is how we engineered the structural backbone that brought this award-winning architectural vision to life.

1. The Challenge of Scale: Three Distinct Towers, One Site

Gateway Parramatta is a highly integrated, mixed-use ecosystem. The project scope required the simultaneous structural design of three distinct buildings:

The 42-Storey Landmark Tower: Clad in a rippling curtain glass wall inspired by the ‘meeting of the waters’ at Parramatta Weir, this tower required a highly rigid lateral stability system to minimize wind sway and support the complex, shifting facade attachments.

The 32-Storey Residential Tower: Architecturally angled to allow sunlight into the public plaza below, this tower features sweeping, curved balconies nodding to Sydney’s bedrock sandstone. JSBC engineered precise cantilevered edge slabs to achieve these organic, sweeping shapes without compromising structural integrity or adding excessive weight.

The 12-Storey Boutique Hotel: Offering 288 rooms, a first-floor function centre, and a rooftop terrace and pool. The rooftop pool demanded highly specialized structural loading, deflection control, and waterproofing integration at the very top of the structure.

2. The Structural “Handshake”: The Colonnaded Podium

The true complexity of Gateway Parramatta lies in how these three distinct towers interact at ground level. The towers rise from a shared, two-storey colonnaded retail and commercial podium that activates a new 2,115m² public plaza.

The Podium Transfer: JSBC engineered a high-strength common podium that serves as the structural “handshake” connecting the developments. This massive structural element acts as a transfer level, capturing the immense vertical loads from the 42-storey, 32-storey, and 12-storey towers above, and redistributing them into the foundation network.
Enabling the Colonnade: By successfully shifting these load paths, our engineering enabled the architect’s vision of an open, colonnaded ground floor—creating the large, column-free spans necessary for retail spaces and pedestrian flow.

3. Deep Urban Excavation: The 5-Storey Basement

Supporting a precinct of this magnitude—and accommodating the parking needs of hundreds of residents and hotel guests—required an immense subterranean footprint. The project is anchored by a massive 5-storey underground basement.

The Geotechnical Reality: Excavating five levels deep in the heart of Parramatta requires highly advanced retention engineering. JSBC designed a robust shoring and retention system to manage intense lateral earth pressures and protect neighboring infrastructure. Furthermore, we implemented a sophisticated foundation strategy to manage the local water table, ensuring the basement remains entirely secure beneath the staggering weight of the structures above.

The Impact: Enabling a Landmark

A project of this scale requires an engineering partner capable of seeing both the granular details—like a rooftop hotel pool or a cantilevered balcony—and the overarching masterplan. By successfully integrating luxury residential, hospitality, and retail into a single, cohesive structural framework, JSBC Consulting provided the backbone that allowed this $80M+ gateway landmark to become a reality.

Category: Hotel