Transcript Siting and orientation ppt

Choosing the place and which
way to face
What should you think about when deciding where to put your building?
The direction a building faces will impact on a lot more than the view –
how do you decide the best orientation?
Location, location, location
Early planning will need to consider where and how a building is located.
There are several angles to consider when answering the question – where
shall I put it?
⌂ is the land you plan to use in a rural or urban setting?
⌂ is it a brown or green field site?
⌂ what’s the local micro-climate like?
⌂ are there any special ecological features that should be
⌂
⌂
safeguarded before, during or after construction?
will your building and landscaping add value to the site?
is the building oriented to maximise potential solar gains
and minimise exposure?
Being located on a south facing slope with
large amounts of glazing results in solar gain.
.For more info go
to bldgssiting_and_orient
ation.htm
Good design uses natural features such as
slopes or vegetation to shelter buildings from
the wind and maximise solar gains. A
significant reduction in heat loss can be
achieved through properly planned siting.
Form and shelter
How can you protect a
building from:
⌂ wind
⌂ rain
⌂ sun
⌂ temperature variations
http://www.dreamgreenhomes.com/plans/esactivehome.htm
The shape and size of a building
influences heat transfer. Compact
buildings that have a small ratio of
surface area to volume will loose
less heat. Apartments also benefit
from sharing warmth with adjacent
properties compared with
detached houses.
Gaining from solar rays
The sun’s rays can warm a building:
glazing on the south side of
buildings will increase this ‘solar
gain’.
Attached sun spaces trap
heat from the sun. Direct
and indirect energy
transfer provides heat to
the adjacent building.
The sun is higher in the sky in
the summer, large over hangs
reduce heat gains in summer
but allow solar gain in winter.
At Hockerton Housing glazed
verandahs gain heat from the
sun’s rays. The floor and walls
then heat the rest of the
building. In the winter such
buffer zones separate the cold
outside and the warm inside.
Massive gains
How can thermal mass be used to save energy?
Thermal mass is the ability of a material to absorb heat energy. A lot of heat energy is required to
change the temperature of high density materials like compacted earth, concrete, bricks and tiles.
They have a high thermal mass. Lightweight materials such as timber have a low thermal mass.
Winter
Allow thermal mass to absorb heat during the day
from direct sunlight or from radiant heaters. It will reradiate this warmth back into the home throughout
the night.
The thermal mass of building components like floors, walls and roofs can be designed to capture
energy when it is plentiful (or excessive), store it and release it later.
Summer
Allow cool night breezes, convection currents, to pass over
the warm thermal mass, drawing out all the stored energy.
During the day protect thermal mass from excess summer
sun with shading and insulation if required.
This rammed earth wall at CAT warms up
when the sun hits it. At night, or when the
temperature decreases, the heat stored in the
wall is released keeping the building
temperature more constant and reducing the
heating demand.
Check……
In which direction should your building face?
How can your building be sited to minimise heat
loss?
How can your building be sited to maximise use of
heat from the sun (solar gain)?
How can your building be sited to utilise natural
elements so it’s warm when you want it to be warm
(e.g. winter, evening, night) and cool when you
want it to be cool (e.g. summer, daytime)?
Can you make use of existing natural features of
your chosen site (e.g. re-using materials, vegetation
for shade, earth for wind protection, slopes for solar
gain)?
Can you site it so it doesn’t create problems (e.g.
visibility, sun loss) for other buildings or so that other
buildings don’t create similar problems for yours?
Why……
• do you think this house has been orientated in this direction?
• are the solar panels positioned where they are?
• are the windows very different sizes?
• is there a porch?
Have a look at http://www.buildingwithawareness.com if you’re not sure of
the answers.
Work it out – design abacus