Milan 29 by Arden Homes

Published: 5 September 2023
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dark and light grey single-level home with yard and driveway Milan 29 with Harper façade.

This display by Arden Homes demonstrates that its possible for a modern home to easily achieve a 7-star rating without compromising on style. These builders understand the importance of orientation, insulation and glazing upgrades required to achieve 7 stars and the savings associated with the choice to include all electric appliances.

Feature home snapshot

Builder: Arden Homes

Location: 26 Origin Drive, Sunbury Victoria – NatHERS Climate Zone 60

Design: Milan with Harper façade

Description: Single storey, 4 bedrooms 2.5 bathrooms

Size: Total area: 264.19m²

House area: 220.68m²

Garage: 37.54m²

Porch: 5.97m²

NatHERS energy rating: 7 stars*

Whole-of-home assessment: All electric with solar PV and battery

*This home has been rated using FirstRate5 5.3.2b under NCC 2019.

Energy and cost savings

Using Sustainability Victoria’s Whole of Home Pilot Tool, the estimated annual energy use, emissions and energy bill amounts were calculated for this home and compared to the same home built to the current minimum requirements under the current version of the national construction code, 6-star NatHERS rating with average efficiency mixed fuel appliances without solar PV. Thanks to the 7-star NatHERS rating and the selection of all-electric appliances, solar PV and battery, the new owners of this home are expected to save 68% each year on their utility bills. Due to the addition of a solar PV system and battery storage this home has a negative energy usage and –1,72 tonnes of CO2-e emitted each year.

26 Origin Drive, if it were a mixed fuel 6-star home without solar PV 26 Origin Drive (actual – 7-star all-electric home with solar PV and battery) Savings [%]
Annual energy use 54,799 MJ -6,167 MJ 111%
tCO2-e emitted p.a. 5.6 -1.72 131%
Annual energy bill $2,417 $769 68%

Table 1: Predicted annual energy use, emissions and costs, including supply charge for 26 Origin Drive under a business as usual and as built scenario.

Annual consumption by end use area

The annual energy consumption of the home has been calculated and is demonstrated in the graph. When modelled as an all-electric home, 26 Origin Drive has most of its energy consumption used by plug-in appliances, closely followed by the heating system. When modelled as a mixed fuel home (using gas for heating, hot water and cooking) most of the energy consumption in the home is assigned to the heating and plug in appliances, followed by the hot water systems.

Milan 29 design living room.

Home features

Feature 26 Origin Drive, if it were a mixed fuel 6-star home design in the same climate zone with mixed fuel appliances 26 Origin Drive 7-star (as-built)
NatHERS rating 6 stars 7.1 stars
Design orientation Northwest facing at the rear of the site Northwest facing at the rear of the site
Insulation - ceiling R3.5 batts and R1.3 anticon roofing blanket to ceiling (garage ceiling has anticon roof blanket) R7 batts and R1.3 anticon roofing blanket to ceiling including garage ceiling
Insulation - external walls R2.0 to external walls R2.7 to external walls
Insulation - internal walls No insulation for internal walls R2.7 to all internal wet area walls (all interior walls insulated for acoustic benefit)
Windows Double glazed to kitchen/living/dining, theatre, hallway (4/10 argon fill/4) Double glazed (4/10 argon fill/4 to all windows)
Hot water Solar hot water system - gas boosted Heat pump hot water
Rooftop Solar PV N/A 6 kW Solar PV system and 14kW of battery storage
Heating and cooling Gas ducted heating, no cooling Ducted reverse cycle heating/ cooling system
Lighting Maximum 5 W/m2 2 W/m2; energy-efficient LED lighting
Milan Home floorplan (Copyright: Arden Homes).

Home design

The Milan design by Arden homes features a compact and efficient floorplan. The living area opens out to a generous sun court, which doubles as an additional outdoor lounge area. This single storey home comes in 26 and 29 squares and is from the Aspire range.

The Milan design features:

  • 4 bedrooms, with walk-in robes
  • a main bedroom with a large ensuite and walk-in robe
  • additional home theatre
  • 2 bathrooms
  • an all-electric kitchen and walk-in pantry

Some of the key decisions involved in this home achieving 26 Origin Drive’s 7-star NatHERS rating are outlined below:

Material colour selection

Milan home design with different façade options showing a range of colour choices.

It's worth considering the impact of colour choices early in the design process. Rating improvements can often be achieved by lightening external roof and wall colours.

Home construction

To meet the requirements of Sustainability Victoria’s 7 Star Homes Program the builders were required to pay extra attention to their construction practices to produce good-quality outcomes. The construction process for this home involved some additional steps ensuring the quality of the final build:

  • Additional care has been taken when installing insulation, ensuring coverage is continuous and free from gaps. This includes around windows and at external corners and wall junctions which are commonly missed.
  • A plaster airtightness strategy has been employed, including caulking of plaster to the concrete slab, caulking service penetrations and caulking and sealing around cavity slider doors.
  • All exhaust fans and the kitchen rangehood are fitted with in-line dampers and are vented externally. This prevents draughts and reduces issues with condensation associated with extraction fans venting into the roof cavity. Quality exhaust fans ensure a healthy indoor environment.
Milan 29 kitchen showing the induction cooktop.

As-built verification

Sustainability Victoria engaged an independent as-built verification assessor to ensure that the home was built to meet its intended energy efficiency targets. The verification check included a blower door test to measure air leakage, a thermography test to check insulation coverage and visual inspections of glazing, ceiling insulation, extraction fan vents and appliances.

Summary

Arden Home’s displays in the Villawood Redstone Estate in Sunbury demonstrate how designing and building 7-star homes can be easy and efficient. The Milan 29 display easily rates at 7 stars by upgrading to double glazed standard aluminium framed glazing along with insulation upgrades. Arden Home’s design flexibility means that this or any other Aspire floor plan can be flipped to be optimised for the ideal orientation to make the home light and bright. The standard inclusion of all electric heating, hot water and cooking with solar PV and battery storage will save the future occupants of this home 68% on their annual energy bills.