Hey, Eric here with 30 by 40 Design Workshop, I wanted to talk about how architects use
the Sun to influence their designs, but rather than speak in generalities, I wanted to use
a detail from a project to show you how it works in practice.
Before we get into the detail you'll need a little background.
One of the most responsible things you can do as an architect is to listen and that,
for me, always begins with the site: the climate, geography, wind patterns, and of course, the
Sun.
Architecture is nothing without light and it's perhaps the most important organizing
force for our work.
It's usually where I start my site analysis, by diagramming the path of the Sun as an overlay
on the site plan, and I'll get into the specifics on how I do this in a minute.
The predominant solar orientation - where the most direct sunlight comes from - here
in the northern hemisphere, is the south.
So, the more of our building that can face south the more efficiently we're able to capture
and use the Sun for natural light, and passive heating, and even cooling as we'll see in
a minute.
This approach not only saves energy reducing lighting, heating, and cooling costs, but
it's also better for our own health and well-being.
For this project, the lot was sloping and rather long with the neighboring residents
close by to the north.
The views to the ocean were all off to the east.
With an east facing site like this you're faced with a dilemma: do you orient the long
axis of the building north and south to give the client the view of the ocean they requested
- from every room – or, do you deny the water view in favor of a more sensible solar
aspect?
Truthfully, I wanted it both ways.
The solution I designed divided the program into public and private wings, each oriented
with their long axes east and west as you can see here in the site plan.
This gave me the long flank of the building to collect sunlight and I could still orient
some of the most important spaces, the master suite, the living room, and a guest suite,
toward the water view.
The, “every room has to have a view of the ocean” is a common request where I practice;
it's one of the main draws of buying a piece of waterfront property obviously.
But, I always try to advocate for a deeper exploration of the site and an interweaving
of the architecture into the larger whole.
This site has many other features to explore in addition to the water view.
By using the circulation to stitch the building volumes together, I could continually change
the perspective as my client moved throughout their house and their day.
Arriving home they would head east and then south and then east again and this combined
with a changing horizon line and sets of interior steps, which mirrored the sloping site, this
allowed each space to capture a different perspective on the site.
Now, let's dig a little deeper on the impacts of the Sun on this specific design solution.
The plan is laid out as three linear bars each stepping down with the topography toward
the water.
An initial approach might be to simply extrude the bar and put a flat roof on it, but this
is less dynamic it doesn't really react to the solar exposure in any specific way.
But, by picking up the southern eave of the roof like this and adding a glazed clerestory
in the void this became a really efficient device for letting in sunlight on the southern
exposure.
The higher you can locate a window on a wall, the deeper it will admit daylight into the
interior.
As we look at the section you can see another solar advantage of the shed roof, it allows
daylight to pass by the roof form and reflect off the taller northerly wing.
Because the private wing contained a lot more program than the public wing - five bedrooms,
a laundry, a library, and a mudroom area - we had to design it as a two-story volume.
The site analysis made it clear that placing it to the northerly edge of the site would
confer a number of advantages, it blocked the views to the neighboring residence, it
served as a wind block from the harsh northerly winds on the site, and if we made it two stories
tall we could use it to help bounce light back to the northerly face of the living wing
as you can see here.
So, I'd encourage you to think about a diverse range of uses when it comes to sunlight and
how it interacts with your architecture.
How can you exploit it understanding that buildings can absorb, block, filter, consume,
store, and reflect sunlight?
Alright, now that you're up to speed on the larger design moves it's finally time for
the details.
Clerestories efficiently daylight interior spaces as we've said, but along with all that
natural light comes solar radiation too, which can quickly overheat spaces and make them
uncomfortable, which is just the opposite of what we're trying to do with our design.
And, here's where the details matter.
To control the light and heat on southern exposures you'll predominantly want to be
considering horizontal elements for screening, that's because the Sun moves from a low altitude
in the winter to a high one in the summer.
Horizontal objects act like the brim of a hat to shade the building and it's the high
angle Sun that presents the most danger for overheating while the low angle Sun is good
for us here in a cold climate, we want to let in the winter Sun and use it to offset
our heating costs.
Horizontal elements can include an overhang, a sunshade, awnings, screens, louvers, or
brise soleil.
Because our design was so linear,horizontal louvers seemed the most appropriate.
Now, we could have just matched the coursing on the siding and called it good but there's
more to it than that.
The spacing and depth of the horizontal louvers can be tuned to your exact geographic location.
Why not, right?
This is where the Sun charts come in handy.
Now, a lot of people have been asking about these and I'll quickly show you how they work.
There are essentially four dates in the calendar year that you care about when considering
the Sun's impact on your architecture.
The solstices in December and June are the points when the Sun is at its extreme arc,
either high or low, and then there's the equinoxes in March and September, these are the midway
- sort of transition - points between the two extremes.
To design the depth and spacing of the louver blades you'll want to know the altitude of
the Sun at solar noon for each of the four important dates.
In this cold climate we can take advantage of the lower angle of the winter Sun for passive
solar heating and our design can keep the higher angle hotter sunlight out in the summer.
Now, there's a really fantastic podcast by the Australian architect Amelia Lee called
the Undercover Architect and she does a deep dive on this topic - I think it's something
like a six-part series - which covers each different exposure and how you might treat
it with your architecture how that impacts design.
Now, she's got her North's and South's all flipped around because, well, she's Australian.
But seriously, it's really well done you need to follow her if you're not already.
Links are in the description below.
Okay, next step is to take these angles and plot these values on your drawing.
Remember the angle is above 0 degrees which is - for our purposes - the horizon.
So, naturally 90 degrees would be straight overhead.
So, here in Maine it's something a lot less than 90 degrees.
Okay, so these are our values for the important calendar dates and given these angles I start
with some basic assumptions about my louver design and then I begin tweaking as necessary
to get the intended effect.
Now, you can use SketchUp or Revit and I really like the app Sunseeker and the real-time augmented
reality especially for renovations.
These tools will all help you study and understand Sun angles much more quickly - and perhaps
intuitively - than sketching it out by hand.
But, for details like these I find sketching to be the most tactile and enjoyable way to
design.
Now, here's what we ended up with for our design and you can see that it balances admitting
ample winter Sun and blocking out the high angle summer Sun.
The rest of the year I tried to balance it out and there's some bit of magic between
the spacing, material efficiencies, and the depth of the louvers, and for that you'll
just have to play around with it to get it right.
The more materially efficient you can be, the less expensive the Sun shading system
will be to construct.
Now, there are a lot of other ways we could have done this including addressing it from
the inside, but the most efficient way to keep the overheating and glare issues from
becoming a problem inside is to keep the Sun from striking the glass in the first place
and that means an external solution.
Now, the last thing I'll mention about the solar design here is that passively heating
spaces this way, it allows you to take advantage of the stack effect too if you add operable
windows up high as we did in our clerestory.
As the interior air heats up and rises and we open the upper windows it sets up a natural
convective flow; exhausting warmer stale air up high and admitting cooler fresh air down
low.
All the resources I used and mentioned in this video are in the description below.
I hope this helped explain some of the design opportunities the Sun can provide.
The data contained in solar charts are immensely useful and pretty easy to divine when you
know what you're looking for.
Smash that like button below if this has helped you in any way, it tells me you stick around
to the end and I so appreciate that!
Be sure to follow me on Instagram for drawings, sketches, and studio process images, if you're
not already.
Cheers my friends, we'll see you again next time.