Pocket Passiv
RESIDENTIAL: single dwelling
PASSIVHAUS PLUS CERTIFICATION
GLEBE, NSW, 2023
Pocket Passiv is a small infill residential studio occupying the unused space of a spatially constrained inner-city terrace house corner block. Occupying the ‘pocket-sized’ footprint of 27sqm, Passivhaus certification makes the home incredibly energy efficient. Beyond its impressive energy efficient design and construction Pocket Passiv offers an exemplar of a rare yet needed typology of inner-Sydney residential housing, infilling constrained urban sites with diverse, well-designed, and environmentally conscious housing options. Aiming to respect its layered historic context and neighbours, Pocket Passiv emerged as a highly considered geometric form.
A modest two-storey studio, the project includes a cozy downstairs area and combined bedroom / study, dramatic double height bathroom, and a smartly configured kitchen / living / dining area. Submerged nearly one metre below the existing ground level the studio retreats into its residential context maintaining sunlight to the adjacent residential courtyards. An asymmetrical pitched roof with a ridgeline that leans towards the street creates a large area for solar panels hidden from view and an architectural proposition that creates a truly contemporary and urban pocket-sized presence. Clad in timber shingles, Pocket Passiv will age overtime, weathering, adding another architectural layer to the rich creative tapestry of Glebe.
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AIRTIGHTNESS n50 ACH@50pascals: 0.52
HEATING DEMAND (kWh/m².yr): 13
COOLING DEMAND (kWh/m².yr): 11
HEATING LOAD (W/m²): 13
PRIMARY ENERGY DEMAND (PE) (kWh/m².yr): 130
PRIMARY ENERGY RENEWABLE DEMAND (PER): 62
PRIMARY ENERGY RENEWABLE GENERATION (PER): 142 -
LOCATION: Glebe, NSW
NCC CLIMATE ZONE: 5 – Warm temperate
NATHERS CLIMATE ZONE: 56
YEAR OF COMPLETION: 2023
TREATED FLOOR AREA (PHPP sqm): 34
PROJECT TYPE: Addition
BUILDING TYPE: Residential: Single Dwelling
CONSTRUCTION TYPE: Timber Frame
CERTIFICATION LEVEL/ ENERGY STANDARD: Passivhaus Plus
THIRD PARTY CERTIFICATIONS: None -
MHRV SYSTEM: Soler & Palau ALTAIR 120H
DOMESTIC HOT WATER SYSTEM: Intaflo Heat Exchange Storage Tank HF1411 (400 Litre)
EXTERIOR WALL TYPE, U-VALUE: Wall Timber 90 + 45 with Timber Shingles, plasterboard, 0.266
FLOOR SLAB TYPE, U-VALUE: Concrete Insulated, 0.543
ROOF INSULATION TYPE, MANUFACTURER: Fletcher Glasswool
ROOF CONSTRUCTION: Timber Frame
ROOF ENVELOPE U-VALUE: 0.219
GLAZING TYPE, U W-VALUE, G-VALUE, U G-VALUE:
AGG Insulglass DGU Low-e Max - Neutral (6:/14/6), 1.06, 0.31, 1.06
EXTERNAL DOOR TYPE, MANUFACTURER, U D-VALUE: Timber Door, 0.392 -
NUMBER OF MODULES: 9
HEIGHT, WIDTH OF ONE MODULE (m, m) : 1.855 × 1.29
HEIGHT OF ARRAY: 0.6m
EFFICIENCY: 95%
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- Certified Passivhaus Plus Standard acknowledging the building’s ability to generate as much energy as it consumes – ultimately becoming a net zero energy building.
- Achieves an air tightness result of 0.52 air changes, and an annual heating and cooling load well below 15kWh/(m2a).
- A life cycle assessment determined the Global Warming Potential (GWP) of Pocket Passiv to be 4kg of CO2/m2/year over a 50 year lifespan, which easily surpasses the exemplar standards of Denmark that require all new buildings to achieve a GWP of no greater than 12kg of CO2/m2/year.
- Low VOC paints and internal finishes
- Heat Recovery Ventilation system (HRV) that ensures a flow of filtered fresh air and exhaust of stale air
- 390-Watt Solar Panels that provide enough energy to offset demand and deem the house carbon neutral in accordance with Passivhaus Plus criteria. -
The location of the studio constrained the design from the outset with the only unoccupied space on the site being the concreted backyard to the rear of the existing terrace house. With an east-west street orientation and overshadowing from the neighbouring two-storey terrace houses the studio’s location become a key challenge when designing to solar passive design first principles.
Avoiding overheating whilst achieving optimal daylight levels further became a key challenge when designing such a small building with high levels of insulation and airtight construction. During the design phase a careful play of glazing re-sizing and re-locating along with testing different insulation levels fed into the Passivhaus Planning Package to balance the building’s performance with the design intention and architectural outcomes. More so, due to the constrained location and footprint, space was at a premium throughout the construction process. A core consideration became balancing increased wall and ceiling thicknesses (to meet high insulation requirements) with maximising the dwelling’s internal floorspace and functionality. This became a constant challenge throughout as new materials and products were constantly researched and tested to see if they could better meet both requirements.
Completing the certification documentation inhouse, with an external certifier from Detail Green has taught us that real time and consistent feedback on the performance of the construction methods was crucial in ensuring any interventions could be seamlessly implemented at the right time. This experience revealed the importance of having an internal Passivhaus designer that was embedded within the project who had an in depth understanding of both the architectural and technical goals of Pocket Passiv. In this instance the architect’s working on the project doubled as the Passivhaus designers ensuring a wealth of knowledge on both the design and performance was consistently present at site discussions.
Project Members
ARCHITECT/ ENVIRONMENTAL: Anderson Architecture
CONTRACTOR/ BUILDER: Akira Barzaghi, Mindful Building
PASSIVHAUS CERTIFIER: Detail Green
PASSIVHAUS CONSULTANT/ DESIGNER: Anderson Architecture/ Simon Anderson
STRUCTURAL ENGINEER: Partridge Engineers
QUANTITY SURVEYOR: EConstruct Consulting
WINDOW SUPPLIER: Kinzel
HRV SUPPLIER: DS Air
INSULATION SUPPLIER: Fletcher
BLOWER DOOR TESTER: Blower Door Services
PHOTOGRAPHER: Tom Ferguson
Awards and Shortlists
NSW Institute of Architects Award for Sustainable Architecture 2024
National Sustainability Award 2023
National Timber Design Award 2023
NSW Institute of Architects Award for Sustainable Architecture 2024
Commendation in the National Houses Awards for Sustainability