BDA Design Principles

1 Passive Design

What
Passive design takes advantage of the local climate to maintain a
comfortable temperature within the house.

Why
significantly reduce or even eliminate need for supplementary
heating and cooling which accounts for 40% of energy usage in the average Australian
home.

How

Orientation to
maximise access to passive solar heating and cross ventilation. This can be
achieved by having a well-insulated building along an east west axis, with
north facing windows to allow passive solar gain during colder periods and
shaded to block this during hotter periods.

Shading
is calculated by determining how many days of the year the house
will need to be cooled to maintain thermal comfort. This is done by calculating
the thermal neutrality* of each location and matching it against the places
average max temperatures to determine when to shade of the internal areas is
required and when to allow sunlight to penetrate in the colder periods.

Thermal
neutrality is the zone where we are most
comfortable and changes throughout the year. In the colder months, 20 degrees
feels a lot warner than it does in the warmer months.

Passive
solar heating is achieved
by orientating the living areas to the north and specifying glazing that allows
solar energy to penetrate and heat the thermal mass within the house. This
creates a greenhouse effect that warms the house in Winter.

Thermal
mass is the extent of a material to
absorb and store heat energy. Solar radiation that penetrates the north facing
windows when heating is required is trapped by the greenhouse effect.
Externally insulated and internally exposed thermal mass absorbs this heat
during the day and releases it slowly into the internal environment in the
evening.

Passive
cooling Melbourne, Geelong and the Surf
Coast are in a heating climate, however on those few days of the year that
require cooling to maintain thermal comfort, openable windows allow for breezes
to reduce internal temperature.  Analysis
of local wind direction determines placement of these operable windows.

Sealing
your home and using Insulation with no gaps inhibits the warm air
escaping, reducing the cost of heating and assisting to maintain thermal
comfort whilst reducing the cost of heating and cooling.

Materials

What

Each building material has a cost made up of the energy needed to
produce and transport it to the site and;

different levels of performance to aid the maintenance of thermal
comfort.

Why material
selection and how they are combined will improve the thermal comfort reducing
the running costs of supplementary heating and cooling. However we must also
think about the amount of carbon dioxide produced in the production of these
materials and ensure this is kept to a minimum.

How

Responsible sourcing of materials through local suppliers and use
of salvaged wood products when available or ensure it has transparent labelling
of its sustainable extraction.

Avoid use of materials on the Living Future Institute red list 

We aim to source as much of our specified items from Australia.  Local products are preferred over products that come from interstate.

Energy

What The devices
we use in our daily living and to maintain thermal comfort require the
production of energy to keep them running. The amount of energy required to run
them and where this energy comes from will significantly reduce the production
of greenhouse gases and reduce running costs whilst maintaining thermal
comfort.

Why In Victoria,
our energy comes from burning coal, the dirtiest of all fossil fuels that
pollutes the air and causes health problems. This unsustainable production of
energy is contributing to global warming and sea level rise.

How

Reduce energy and carbon dioxide production through smaller
building footprints and specification of local products that require less
energy to run and photovoltaics that use the nuclear energy of the sun to
capture the energy required to run them.

Designing for future installation of renewable energy systems such
as pre-installing wiring for an electric car.

Provide for energy needs through on-site renewable energy and
storage to maintain supply.

Water

What Fresh drinking water is essential to live and supply must be
managed carefully. Australia is the driest inhabited continent on earth and
rainfall is expected to decline with the rise of global warming. On average,
Australian’s use 100,000 litres of freshwater annually (the highest per capita
in the world). And when we include the 
embodied water from our food and products this number sky rockets.

Why
material selection with low embodied water and design that enables
the harvesting of water will significantly reduce the burden on the supply of
freshwater for human consumption and provide security of water supply for use
in gardening. A necessary element for the production of food on site.

How

Specification
of roofing and storage with capacity to harvest and store enough water to
supply 100% of water needs. Average annual rainfall for the location is
calculated, allowing us to determine the size of roofing and storage
requirements necessary to sustain the expected number of inhabitants. 

When
available at location, non-potable water is used for all non-potable uses.

Waste

What during design and construction of housing, significant amounts of
material waste are produced. Also, use of material and energy to produce
buildings that don’t incorporate the use of passive design and that are not
durable or adaptable to future re-use is a wasteful use of material and energy.

Why Reducing the waste produced during design and construction will
significantly reduce the production of greenhouse gases. Design and
construction that is durable to the climate conditions and future uses will
reduce the lifecycle cost of the building. Design for deconstruction will allow
material to be recycled at the end of the building’s life.

How

Design
and specification of material with consideration of durability and
deconstruction.

Collect
waste on site for recycling

Plan
for adaptable re-use of the building.

Place

What Restore or enhance the site and community conditions post
construction and enable food production.

Why Native flora eliminates the need for fertilisers and pesticides
and growing of food for use will significantly reduce the production of
greenhouse gases used to produce and transport food on large scales. It will
encourage the use of the place by local fauna.

How

Design
and specification of native flora that don’t require petrochemical fertilisers
or pesticides to maintain.

Dedicate
a portion of the site to the growing of food

Maintain
or increase the density of the site

Building
scale appropriate to the neighbourhood

Place/space
for occupants to connect with neighbours/community

Health and Happiness

What To provide
places/spaces that enhance the health and happiness of the occupants through material
specification that doesn’t off-gas toxic gases and design that enhances
airflow, access to natural light and to nature.

Why To provide
spaces that don’t adversely affect the health and that promote happiness in the
occupants.

How

Design views to outside and daylighting for all occupants.

Design space that promotes cross-ventilation of spaces or utilise
chimney effect to maintain good indoor air quality.

Design that allows occupants to directly influence the air flow
and temperature of the internal environment through direct input or controls.

Provide flexible working options