Conventional construction (clt + STEEL & CONCRETE)

Seed House

Client:

James and Susie Fitzpatrick

Architect:

Fitzpatrick + Partners

Structural Engineer:

TTW

Head Contractor:

David Campbell Building

Location:

Sydney North Shore, NSW, Australia

Building Methodology:

Hybrid, CLT, Concrete, Steel
XLam CLT (208m3)

Owners, James and Susie, were motivated to build a custom, sustainable home for their family that accentuated the natural sloping landscape of the block, using seed pods found on the property as inspiration. Responding to their desire for a natural solution on a sloping site, XLam worked with project stakeholders to deliver an intricate, functional design using cross laminated timber (CLT) in conjunction with traditional materials.

Located on Sydney’s North Shore, this stunning 658m2 award-winning house was a feat in of itself. Crowned the overall winner of the Australian Timber Design Awards 2019, the home took over eight years to come into fruition, including a design period of three years and more than 400 drawings.

The concept and namesake of the home derives from the form of a seed pod. The design works as a series of linked pods, divided into functions, which can be opened or closed in a flexible arrangement, depending on time of day and usage.

Purposefully built to accentuate the natural landscape, the design aims to link the outdoors with the indoor spaces with no restrictions to the view while maximising privacy. The surrounding nature also informed the material palette of timber, steel, concrete, and stone, with every material and finish selected on the basis of criteria including environmental performance, and the ability to provide a raw, natural aesthetic.

The project makes extensive use of XLam CLT which met the architects vision and key drivers for the project including; biophillic design, use of natural materials, sustainability, lightweight construction, overcomming site constraints and reducing the use of materials such as concrete.

Structural System

Sitting harmoniously within the bushland surrounds, The Seed House is a bold celebration of a mass timber used in a conventional build, featuring XLam CLT and native timbers, natural stone, glass, and black steel. XLam CLT panels and glulam beams were used to form the structure of the interconnected, cantilevered pods that make up the home.

Built predominately from XLam CLT and glulam beams, mass timber forms the structural frames, cantilevered pods, as well as the spectacular spiral staircase, which elegantly winds down three floors. The XLam CLTstructure has extravagant cantilevers exposed internally, with all exposed XLam CLT elements containing hidden wall to floor connections.

In addition to the CLT Panels used througout the home, the feature spiral staircase is also prefabricated from XLam CLT. To acheive necessary stiffness and stability, the treads were fitted individually and thread over a six-metre structural steel tube member. As individual treads were fitted, each one had to be screwed into place using hidden screw locations.

The strength of the house is largely reliant on the portal frames formed between the XLam CLT floors and walls. The side walls wrapping the XLam CLT cantilevered pods use both the longitudinal layer direction and the transverse layer direction, acting as deep beams to cantilever off steel portal frames. The kitchen is supported by a highly architecturally refined roof truss with a top chord of composite XLam CLT and steel.

Outcome

By working alongside the Architect and Builder, XLam was not only able to create the owners dream of a sustainable, healthy, and natural ‘forever home’, but it also saw The Seed House receive overall winner of the Australian Timber Design Awards 2019.

XLam CLT made from timber, a natural material, meeting a key driver for the project
Biophillic, timber is beautiful, warm and inviting,creating a healthy home that improves physical and emotional wellbeing of occupants
XLam CLT is sustainable and made from PEFC certified timber
Lighter than concrete and steel, XLam CLT allowed for a reduction in foundation loads and distribution requirements enabling the architectural vision to be acheived despite the challenging sloping site
Pre-frabricated MTC is safer - with less processes being performed on site and a lower headcount, MTC using XLam CLT reduces the risk and instances of injury
Reduction in carbon emissions, sustainable timber stores CO2, creating a lower carbon footprint than concrete and steel