Solar Analysis

In Brisbane we want zero sun in Summer, a tiny tiny bit in Spring and Autumn and a reasonable amount in Winter. Analysis is straightforward and shows:

Shading Take 1 : Base

Morning view from the sun. Top row: Summer. If you see windows (in red), it’s bad.
Bottom row: Winter. If you see windows (in red), it’s okay.
image 1
Afternoon view from sun. Top row, Summer at 17 (5pm) shows a very very hot deck.


  • L2 east facade needs strong external shading. Operable shades would be best, or horizontal slats to maintain view would be okay.
  • L1 east : will have screens and these should be dense.
  • L2 north: needs more overhang. Extending the roof would be an option but it would have to come out a long way. Window hoods would be fine and more traditional.
  • L1 north: Medium overhang via continuous element. The wing roof overhang is about right – 100% sun in Winter. Could be slightly bigger to block more spring sun.
  • L2 west: no windows is preferred or tiny
  • L1 west: Movable shade is required. A fixed shade (pergola) would block winter sun. A pull down or around would work. Must be pretty dense.

Shading Take 2

Let’s make these changes and re-test: external operable shades to west, slats to east, overhangs to north enlarged. Try a west window as a horizontal slot.

image 2
Better. Minor changes.
image 3
Better. Minor changes.

That’s not great: full Sun at 6am! With intense, 2:1 (i.e. 200mm deep @ 100mm spacing:

Shading Detail – East

Do we need expensive operable shading on L2 at the front? Let’s try fixed shading:

image 4
6am in Summer with 1:1 (100mm deep x 100mm shade)
image 5
9am in Summer with 1:1 (100mm deep x 100mm shade)

image 7
Shading at 7am: overhang is useless
image 6
Shaded by 7am in Summer: 200mm deep by 100mm

So for the east (and west) it’s either very deep fixed shading (ugly), or operable shading. These could be electric. A cheaper version would be manually operable, as it only needs moving rarely. An even cheaper option is internal “plantation” shutter, but interior shading lets in a lot more heat than external.

Shading Take 3 – Final

And here is the summary:

  • Operable shading to east and west.
  • No windows to west if possible. Few to east.
  • Traditional window hoods (600 deep) with eastern sides to L2
  • Dense battens for L1 east
  • Overhangs to L1 north: 600mm, then 900 for deck
image 8
Shading elements in blue. Windows in red. South facade omitted. From NE.

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