We’re going to use SketchUp and some extensions to find out how sunlight falls on (and in) your courtyard and how to optimize the design of your courtyard for optimal daylight.
Which extensions are we going to use?
We’re going to use a couple of FREE extensions and one paid extension from Extension Warehouse:
What are we trying to do here?
We’re going to find out, and optimize for, the following:
- When light hits your courtyard
- Where light hits your courtyard
- How much light hits your courtyard
So, let’s take a look at your courtyard, shall we?
Getting your model setup
Make sure you have all the relevant context in your model. This includes buildings, terrain, and landscape around your site that will affect the way sunlight hits your building. You can get context and location models from services like PlaceMaker and CADMAPPER.
How many hours of direct sunlight is my courtyard getting throughout the year?
We’re going to use the extension Sefaira to find this out. Remember to group your building separately from the others and work inside that group. There are two main steps:
- Checking your entities
- Setting up analysis questions, dates and times
Check your entities
Analysis Question - Do I get at least three hours of direct sunlight in the courtyard between 9:00 AM and 5:00 PM during the entire year? (Also, where do I get it?)
Where do I get at least three hours of direct light in my courtyard every month?
Ruh-roh. Looks like your courtyard isn’t getting enough daylight at this point. This courtyard is great for growing mushrooms, not so good for employee health. Here’s what’s going on -
The courtyard received NO direct light for four months of the year!
It received very little for two more months
One end seems to get quite a bit more daylight than the other
Wait, what does that actually mean? Exactly when and where am I getting the light I’m getting, and what does that look like?
We’re going to use the extension Curic Sun to figure this out. Curic Sun creates a huge Sun Path diagram over your site and automates the movement of the sun over it. Two things to be careful about:
Set your globe size to a reasonable number (2x was a good multiplier for the current model)
Set the center of the sun to the center-ish of your courtyard
Then, we’re going to look at the movement of the sun at a particular time over the entire year. For example, what is the sunlight pattern and movement at 9:00 AM every day during the year?
Follow along below to see what a setup and run of this example would look like.
Observation: There’s almost no direct light in the courtyard at 9:00 AM at any time during the year. The closest we get to direct sunlight at 9:00 AM is somewhere close to June.
GREAT! Let’s do that for all the other hours between 9:00 AM and 5:00 PM, shall we?
RESULTS: Time to pace the floor in an anxious manner while rubbing temples. Your courtyard isn't getting anywhere near the right kind of light, for the right amount of time, or in the right place.
It’s FURIOUS DESIGN TIME! Run the above process on multiple iterations of your courtyard to find a configuration that works better for daylight availability. You’ll find that many different options work and that some work better than others, but the data from all of them is invaluable.
I found one that works better - moving the courtyard up a couple of floors + making the entire building a floor shorter.
Okay, the design’s moved forward at the speed of light. My courtyard is LIT, I mean actually lit at the right times. But is it too bright? And what can I do about the extra light on the North?
Good job on the courtyard design. Here’s a sample SketchUp shadow study at noon:
There’s a bright spot under the skylight. What does that look like in color?
Looks great! But it also seems that the light might be too bright and the contrast might be too high. Let’s run a photo-real render in V-Ray to see what it WOULD look like.
Interestingly high contrast, but we did turn off all the lights in the building to look at JUST the daylight. What ARE the actual illumination levels in lux? Remember, a bright day is about 10,000 lux while direct sunlight on a hot, clear day is around 100,000 lux. We’re assuming a very bright day with a CIE Clear Sky to get an idea of what the worst will look like, and using V-Ray’s Lighting Analysis module to do so.
We have around 8,000 lux in the blue area and around 75,000 lux in the red. That’s good, but not great. We need a little more shade to fix this situation. Let’s bring in some nature.
Which actually looks like...
The tree will also shade the northern portion of the courtyard as the sun moves over it during the day, making sure that at least 50% of the courtyard is shaded at all times.
Now that you’ve designed your courtyard for optimal daylight, imagine what you can do next!
Thanks for reading and happy sketching.
About the AuthorMore Content by Hariharan Natarajan CEM, LEED AP (BD+C)