# Minimum 2 hours direct sunlight on a window

Hi,
I am facing a problem , which I am not sure how to solve . I am not even sure if this is a valid question, but I thought to share and get some insight from others.

Apartment Design Guide (ADG) in NSW, Australia requires minimum of 2 hours direct sunlight between 9 am and 3 pm at mid winter. We need to validate a design and see if it is complying with the requirement.

We have already set up the study and can get the result to show which part of the facade will get minimum two hours of direct sunlight , So thanks for creation of this amazing tool,
However the question is, what if part of the window get direct sun in mutually exclusive time bracket?

Let me elaborate with specific scenario:

What if my main test point ( Lets say at the middle of window ) gets 1.5 hours of direct sunlight from 9 am till 10:30 am.
Another test point which is located on the top right hand side of the window , will ONLY get direct sun between 2:00 pm and 2:30 pm.

No point on the surface of window will get direct 2 hours of sun light , but overall the room is complying with ADG requirement.

Is there any way to consider the window area as a container and test for above scenario?
Any help is greatly appreciated .

Welcome to the discourse.
I think the first think you should know is the code requirements regarding the area of the window to be covered. From your scenarios is not clear if the window should be 100% exposed or, in general, what is the minimal exposure % required.
After that your question requires â€śtechnicalâ€ť solution in LB, which is to calculate the area exposed for each window. This is doable, but not straight away with just LB components.
-A.

1 Like

Hi Abraham and thanks for reply.

I went through the code, It does not describe the minimal required exposure % !?!

However for the for the sake of argument, letâ€™s say minimum 20% of window should be covered with direct sunlight for the specific time-frame , if that time frame is going to contribute toward overall compliance.

The only other factor specified in the code is following , which I guess can somewhat replace the % of the window or the area. :
Minimum of 1m^2 of direct sunlight, measured at 1m above floor level, is achieved for at least 15 minutes, which somewhat can work as percentage. ( Not exactly the same thing , but somehow similar)

I guess my question is , Can someone please guide me to an example when the amount of direct sun is measured on a surface a s whole , rather than calculation for a single point !?