Portarlington · Renovation and extension · 2021
Park Street
A 1960s family home redesigned and extended to accommodate a growing family, with a stronger connection to its north-facing garden. The design retains the character of the original house while creating generous shared spaces and a separate parents’ retreat.
Design and contract administration · Miles Paterson
Design brief
Park Street involved the renovation and substantial extension of a 1960s brick-veneer home in Portarlington.
The owners wanted to accommodate their growing family while creating a more direct connection to the large rear garden. The brief called for individual bedrooms for the children, generous shared living areas and a separate parents’ retreat.
Environmental responsibility was central to the project, with an emphasis on retaining the existing building, reusing materials and improving thermal comfort and energy efficiency.
Design response
The extension draws on the original home’s gabled form, reorienting it towards northern sunlight and the garden. A lower connecting link separates the two wings while establishing a cohesive architectural composition.
The resulting L-shaped arrangement brings the garden into the centre of family life. The original home was extensively replanned to accommodate the children’s bedrooms and reconfigured kitchen, dining and living spaces, establishing a more functional relationship between the existing rooms and the garden. The extension introduces a separate living area and parents’ retreat, including the main bedroom and ensuite.
Together, the redesigned existing home and new extension balance shared family life with opportunities for privacy, while connecting both wings directly to the outdoor spaces.
Vaulted ceilings in both living areas reinforce the relationship between old and new. Weatherboard cladding, cypress pine and restored Baltic pine flooring establish a consistent material character, complemented by reused fittings and salvaged architectural elements.
Environmental design
The renovation sought to improve thermal performance while retaining as much of the existing building as practical.
The existing building envelope was insulated, including beneath the floors, while original timber windows were restored and fitted with improved glazing. The extension incorporates insulated construction, double-glazed windows and extended eaves to control seasonal solar gain.
Opposing operable windows encourage cross ventilation, taking advantage of Portarlington’s coastal breezes to provide opportunities for passive cooling.
Floor plan
The floor plan illustrates how the original dwelling and new extension form two connected wings around the north-facing garden.
The arrangement provides separation between family and private spaces while maintaining direct connections to the outdoor areas. The orientation of the extension also supports winter solar access and summer shading.
Performance in use
The upgraded building envelope, passive solar design and efficient building services work together to reduce household energy demand. Rooftop solar generation and battery storage further reduce reliance on grid electricity, while wood heating provides an additional source of winter warmth.
Over the assessed year, solar generation was conservatively estimated to exceed household electricity consumption by 49%. Solar and battery storage supplied approximately 93% of the home's electricity requirements, with considerably more electricity exported to the grid than imported.
When firewood is included, total annual household energy inputs are estimated at approximately 11,633 kWh, with wood heating accounting for 58%. Annual household energy costs were approximately $690 after government rebates. Estimated gross operational emissions were approximately 3.0 tonnes CO₂-e, including firewood combustion. After accounting for the estimated avoided grid emissions associated with electricity exports, the indicative net balance was approximately 0.9 tonnes CO₂-e.
The heating system presents an opportunity for further improvement. Replacing the wood heater with an efficient reverse-cycle heat pump could reduce total annual energy inputs to approximately 6,000–6,350 kWh. Under this illustrative scenario, the existing solar system could generate more electricity annually than the household consumes, making the home a net annual electricity exporter.
Annual performance
- Electricity supplied onsite
- 93%
- Surplus solar generation
- 49%
- Annual energy cost
- $690
Notes: Performance figures cover October 2024–October 2025 and are based on utility bills, Tesla monitoring and estimated firewood use. Solar generation assumes solar-only battery charging. Annual energy cost includes $300 in government rebates and excludes estimated EV charging costs. Carbon estimates include biogenic firewood emissions with no regrowth credit; export benefits use average Victorian grid emissions. Embodied emissions and the firewood supply chain are excluded.