The first two stages of dwellings at Defence Housing Australia’s Crimson Hill development adjacent to Lane Cove National Park at Sydney have achieved high levels of sustainability through a combination of pared down materiality, recycled materials, landscape integration and energy-efficient design and technology.

Designed by Bates Smart and constructed by Grindley, Tubbs View and Hamilton Corner needed to meet the requirements of the Urban Development Institute of Australia’s EnviroDevelopment tool, with the whole estate masterplan achieving a six leaf rating.

Hamilton Corner is a two-storey building comprising seven terraces and 16 apartments around a communal courtyard.

Tubb’s View

Tubbs View consists of two four-storey apartment buildings that follow the existing contours of the sloping sandstone site, with paths and communal gardens connecting multiple building cores. The use of multiple cores allowed the architects to reduce the need for corridors within the buildings.

“Clever design and close consultation with the Ku-ring-gai Council resulted in DHA securing approval to construct buildings up to 25 metres high, rather than a standard 16 metres. This was achieved because Tubb’s View respectfully considered the local landscape through its structural form and building palette, as well as the integrated sandstone wall,” said DHA Lindfield development manager Peter Shellie.

“Tubb’s View represents an innovative design response to a unique site with a specific set of constraints. The stepped building design was an architectural, engineering and construction feat that was achieved on a particularly complex site. The buildings embody the best elements of contemporary Australian architecture and response to their place.”

Off corm concrete with spotted gum cladding

The 93 apartments are a mix of one-storey and two-storey dwellings, 80 per cent of them with a dual aspect for natural light and cross-flow ventilation. All receive at least two hours of sun through the day in midwinter, reducing heating costs.

Huon pine plywood soffits and bushland path

“At the heart of the [Tubb’s View] buildings are some simple design principles, which provide some of the highest standards of internal amenity and environmentally responsible design available in the market today,” David Tordorff, Bates Smart project leader and associate director, said.

“The use of multiple lifts and entry points significantly reduces the need for internal corridors and increases the amount of apartments with a dual aspect. This in turn gives residents a better outlook, and increases daylight penetration and cross ventilation. The design also aims to establish a new integrated community connected with bushland trails and elevated walkways, and interconnected communal spaces that promote community interaction and wellbeing.”

In the construction of both projects, the focus was on reducing the carbon footprint of the buildings through careful materials choices. Natural off-form low-CO2 concrete was used to reduce the need for additional finishes, and timber has been used extensively in the form of spotted gum cladding on vertical surfaces and in bushfire zones as it weathers well and has fire-retardant properties, and plywood was used for non-exposed soffits.

Sandstone sourced from the site has been used extensively. The brownfields site, which sits within the grounds of UTS’s Lindfield campus, had formerly been used as a car park. During the civil works stage of the project, the existing sandstone retaining walls were dismantled and reused, as was excavated sandstone rubble.

Overall, more than 60 per cent of demolition and excavation materials were reused onsite in paving, cladding and landscaping. Recycled steel was also used in the buildings, and to reduce the embodied energy of all materials, preference was given to local manufacturers and suppliers.

The site also had significant areas of native remnant bushland. A detailed ecological assessment was undertaken and endemic species protected and used as a feature of the developments to create linkages and common area spaces. The bushland setting also heavily influenced the ‘treehouse’ design of the apartments.

Where clearing was carried out, replanting used indigenous seeds that were collected from the site, propagated and reintegrated into the landscaping, which uses water sensitive urban design principles. More than 90 per cent of the plants now on the site are native, and the majority of those locally occurring species.

The buildings have solar panels to reduce main-grid energy use, clerestory windows for additional natural light, solar shading elements including metal screens to reduce thermal loads and energy-efficient appliances. Rainwater is being harvested for reuse.

The ESD consultants, Cundall, estimate the buildings will use 60 per cent less energy and water than a standard multi-residential development.

There is an education strategy in place for residents that will encourage them to recycle waste and utilise composting as part of promoting ongoing sustainability.

“We are immensely proud of the development. It is proof that historically significant and challenging sites can be transformed into thriving and liveable spaces effectively and respectfully through design, innovation and teamwork,” Mr Shellie said.

DHA’s first multi-residential apartment project in Sydney, the dwellings will be occupied by a mix of Defence personnel and their families, and both owner-occupier and tenant civilians.