5 star rated houses in Victoria, Australia

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In Victoria all new homes built since July 2004 have been required to achieve a 5 star rating.

This means it is compulsory for new houses to have:

  • Star energy rating for the building fabric, and
  • A rainwater tank for toilet flushing or a solar hot water system, and
  • Water efficient shower heads and tap wear.

The average energy efficiency rating of houses in Victoria was only 2.2 stars before the introduction of 5 star standard. From 1 May 2008, the 5 Star standard will be extended to cover alterations to homes and relocations of existing homes.[1]

Contents

[edit] Why five stars is not enough

The five star rating system in place in Victoria is well below current standards in Europe. For example, it has the following shortcomings:

  • the efficiency of appliances (heating, cooling and electrical) are not assessed
  • the use of energy intensive appliances that can be avoided by good building design - such as evaporative coolers and air conditioners - is not assessed.
  • the use of thermal mass is not optimised - for example large unshaded brick walls facing north are allowed.
  • double glazing is not required - single glazing has a higher heat loss through windows.
  • rainwater tanks when fitted are very small (2,000 litre minimum)
  • no greywater plumbing is mandated.
  • the embodied energy of building materials is not considered.

A move to 7 star standards is required to reduce carbon emissions and energy use for residential housing. The final goal of reaching zero emissions housing needs to be set.

[edit] Examples of 5 star houses

[edit] Surrey Hills - 2 houses on a main road

These two houses house is newly built on a cleared block. They are on a main road. The price of the land for both would have exceeded $400,000.

The front of the house 1 is unremarkable.

At the rear of both houses:

  • A single solar hotwater panel on the north facing roof, but no solar photovoltaic panels. A lot of solar potential is wasted here.
  • A swimming pool is installed - which is a waste of water and chemicals.
  • There are no eaves or other shading over the north facing rear windows - which will transmit excessive heat into the house over summer months.
  • Brick thermal mass is also exposed to north facing sunlight - rather than being insulated byh a facade or shaded. This will also store and transmit excessive heat into the house over summer months.
  • The rear windows are not double glazed

The front of house 2 is reveals a large evaporative cooler on the roof, no eaves around the house, and extensive external brickwork.

These two houses house is newly built on a cleared block. They are on a main road. The price of the land for both would have exceeded $400,000.

[edit] Three north facing houses in Surrey Hills

The front of these three houses are all north facing, and have the following shortcomings:

  • Little or no eaves or shading over masonry north walls or windows - both will transmit excessive heat into the house over summer months.
  • No solar photovoltaic panels. A lot of solar potential is wasted here.
  • No double glazing

[edit] Houses built at or near the Waverley Park site

These houses have the following shortcomings:

  • Small eaves over external masonry north walls or windows - both will transmit excessive heat into the house over summer months.
  • No solar photovoltaic panels. A lot of solar potential is wasted here.
  • No double glazing
  • Many houses have evaporative cooling units

[edit] Cranbourne Estate 5 star houses

These houses have similar shortcomings to those listed for the Waverley Park site houses.

[edit] Moving to 6 or 7 star ratings

A Master Builders Association (MBA) survey has that showed Victoria's five-star minimum energy rating had added $7600 to the cost of a new house, and that six and seven-star ratings would add $10,000 and $14,000, respectively. The Victorian State Government is considering implementing a six-star minimum.

However, the MBA, which lobbied in the past to minimise the cost and effectiveness of the 5 star rating, is lobbying against the introduction of a new 6 star rating, citing housing affordability and the housing crisis as reasons against upgrading the rating.

However, some builders say that five-star compliance has only added only about $1000 to $2000 to the cost of a new house, and that six-star option has added about 1% to 2%, which equates to $4350 extra for a house priced at the Melbourne median of $435,000.

THe Green Building Council has pointed out that increasing green star requirements from 5 to 6, while adding to housing costs, would reduce household costs in the long term, a factor which will become more important as the price of water and energy will be increasing in the future.[2]

Moving to 6 star, or preferable 7 star mandatory building ratings could see:

  • Many houses becoming almost self sufficient for water
  • Houses producing as much electricity as they consume
  • Elimination of air conditioners - the main appliances causing peak power load on hot summer days
  • Greatly reduced carbon emissions associated with domestic housing, reducing Australia's overall carbon emissions
  • The use of much more energy and water efficient appliances.

[edit] See also

[edit] References

  1. 5 Star House, Victoria, Australia
  2. Six-star energy rating adds $10,000 to cost of new house: MBA, The Age, November 21, 2008

[edit] External links



This article is part of Greenprint that identifies strategies, actions and approaches for moving us towards a sustainable future.


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