CLIMATE & A CHNAGING VICTORIA

Passive Housing Language - Third Skin.

Design strategies and movement within the 1960s Passive House is a global building standard which sets performance levels for the comfort and energy performance of houses.

Ultimately the standard is about achieving adequate comfort within a design without the need for action or energy.

Its principles is to be able to control solar radiation which can be captured or avoided during specific times of the year to maintain comfort within the built environment. It avoids the use of artificial heating and cooling.

Basic design principles such as allowing winter solar radiation to heat spaces or surfaces to provide additional heating to the space. During the summer months this same radiation can be blocked using shading devices reducing unwanted heat

gain. (Barnett, n.d)

Key principles of the use of insulation which prevents thermal conductivity between the building envelope and the external environment. A building envelope and each material within the envelope will have a U-value (thermal transmittance), the lower this value the less heat transfer occur through the building. A lower U-value will assist in providing a comfortable environment without additional heating and cooling. Thermal mass can also be used to “store and radiate heat

over time”. (Barnett, n.d)

As explained there are limitations to a passive approach. These include decreasing life expectancy if constant below 18o C for the elderly or high heat exposure from heat

waves. (Barnett, n.d) Humans experience comfort in different ways these include air temperature, humidity, air movement, radiant temperatures, physical movement and clothing worn.1

Ways to achieve comfort is through:

Evaporative cooling - “utilises... cross ventilation breezes and fans to evaporate sweat off our skin, which cools our bodies in the process of liquid turning into gas”.1 High humidity levels will decrease our comfort and evaporative cooling performance decreases as humidity of summer weather increases.

Refrigerant Cycle Cooling - ‘heat pumps’ enable us utilise cooling and heating modes. They generally have efficiencies of 3.5-4.5x. This type of cooling dehumidifies indoor air as it operates, allowing us to stay comfortable at higher air

temperatures (Barnett, n.d).

Passive Housing Explained

Insulation - Foundation to roof cavity creates an efficient envelop and minimises heat losses and gains.

Glazing - low emissivity double or triple glazed. Thermal broken frames or non metal frames (with high thermal conductivity).

Thermal Bridging - Weak spots in building envelopes are known as thermal bridges. These can be cause temperature fluctuations in the envelope.

Air tightness - airtight barriers boost efficiency and prevents draughts. Heat recovery systems manage this fresh air Ventilation: Heat Recovery Ventilation (HRV) systems are used to replace stale humid indoor air with fresh air. Warmer incoming

air is cooled by the outgoing air in summer and the warmer outgoing air heats the cooler incoming air in winter.

Due to the high efficiencies minimal energy is used to heat up 3 degrees of air to 12 degrees (~4x).

Passive Housing Key Criteria

Indoor Air Quality – humidity levels that avoid condensation issues, controlled by HRV systems that guarantee fresh air flow rates Airtightness – door blower tests are used to certify ‘as-built’ performance

Occupant comfort –temperatures only exceed 25 degrees for short periods.

Space cooling & heating– annual cooling and heating energy required to maintain comfort levels

Primary energy – total annual energy demand and renewable energy generation.

If the envelope is created correctly a 6-8KW solar system can produce more energy than its consumption.

Barnett C. (Third Skin) (n.d), ‘Passive House & Passive Solar Relationships & Language’. Retrieved from LMS.

According to CSIRO and Climate Change Australia Victoria the following changes will occur by mid century: (CSIRO, 2020). As a class through out reasearch into how the environemnt will change within a 2050 context we identified a number of key outcomes which will influence our design approach. These are highlights in the diagram left, where we will see decearses in rainfall, projected warming and increase in hot days and loss of biodiversity.

These factors directly influenced how I approached my design through considering to optimise orientation through pivoting the form as well as inclusive of rainwater collection tanks, and the focus o outdoor ammentity and green space to futher biodiversity outcomes

Co-Health predicts that by the year 2031 there will be a need for an additional 18,000 health services within Collingwood. This prompting the need to direct services exactly where its needed within most vulnerable areas (See Demographics Section). The extrapolated date to a 2051 context shows that the need for healths services will rapidly grow within Collingwood with an increase by 220% overall. Similarly if we look at historical data for social housing supply and demand we can predict future trends in the need of social housing. By the year 2051 we will need around 3x more social housing than we are currently supplying, a huge increase in development and density is needed to achieve this.