Sep 2023

Kaleen House | Ben Walker Architects

The Malcolm Moir and Heather Sutherland Award for Residential Architecture – Houses (New) – Australian Institute of Architects ACT 2023

Sep 2023

Kaleen House | Ben Walker Architects

The Malcolm Moir and Heather Sutherland Award for Residential Architecture – Houses (New) – Australian Institute of Architects ACT 2023

Image of exterior of house looking through large open glass doors into open plan living, 7.4 star house designed by Ben Walker Architects and energy rating by Powerhaus Engineering.

A 7.6 star house in Canberra: it comes down to good design

FINAL ENERGY RATING: 7.6 stars
SIZE: 188m2
LOCATION: Kaleen, ACT
ARCHITECT:   Ben Walker Architects
ENERGY ASSESSOR:   Powerhaus Engineering
BUILDER:   Walmsley Building Solutions
AWARDS: The Malcolm Moir and Heather Sutherland Award for Residential Architecture – Houses (New) – Australian Institute of Architects ACT 2023
PHOTOGRAPHY:  The Guthrie Project
Featured in Sanctuary magazine issue #65

Reaching a 7.5 ⭐️ energy efficiency rating in (cooler climates like Canberra) can be challenging. This award-winning new home designed by Ben Walker shows a precise use of windows to balance design with thermal performance and comfort.

Key design decisions for 7+ stars and energy efficiency

  • The building form runs in a long block east to west, creating a long north-facing facade.
  • The form of the building is relatively simple, keeping external surfaces to a minimum and reducing unwanted heat loss and gain.
  • Internally, the living areas and some sleeping spaces are located on the north, while service areas, bathrooms and study are on the south.
  • The living area has a large amount of windows allowing for plenty of winter sun, passively heating the house all winter.
  • Eaves on the north are sized to block summer sun, preventing the sun and unwanted heat from entering the living spaces.
  • Restrained use of windows to other facades: east, west and south. This lowers the window to floor ratio – an important metric in achieving higher star ratings.

Energy efficient building details

Thermal shell

  • Ceiling insulation: R5
  • External wall insulation: R2.5
  • Slab insulation (underneath and edge): R1.5 polystyrene
  • Building wrap: Pro-Clima Solitex Extasana (this wrap is air-tight and vapour permeable)
  • Windows: AWS thermally-broken aluminium-frames with double-glazing, high-SHGC low-e coating

All-electric building details

  • Solar: 13.32kW solar system
  • Battery: Tesla Powerwall 2
  • Hot water: Thermann X Hybrid 300L heat pump
  • Heating: In-slab hydronic heating powered by Galleti 16kW electric heat pump
  • Heating & cooling: Daikin multi-split reverse-cycle air-conditioning to living area
Arial view of Ben Walker Architect's energy efficient Kaleen House, showing north facade with large glass doors and pool.

The full North wall of the living room is glass, creating not just connection with the outdoors, but a valuable winter sunbank.

East view of the 7.6 star energy efficiency Kaleen House by Ben Walker Architects, showing no windows

The east wall of the house has no visible windows and maintains privacy to the street, while enhancing thermal performance.

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