Section 81 - Daylight to existing habitable room windows

Hello,
I'm wondering if anyone has any knowledge or experience with what's allowed under section 81 of the Victorian Building Regulations when a habitable room has multiple windows. The situation is this:
There is a potential double storey extension where the neighbouring property has a bedroom with 2 windows - the main a north facing window, the other a smaller, frosted west facing window, as shown below.

My 2 questions are:

• Do sections 81(1) and 81(3) of the building regs apply to the west facing window regardless of the north facing window?
• If, hypothetically, both buildings existed (with 1.5m distance between the houses with a 6m high wall on the grey building, and less than 1m clear to the sky between them), but the small west facing window of the blue building did not exist, and the owner decided she would like to install a small, frosted west facing window (to make it as it is now) would section 85 of the building regs prevent this being allowed, regardless of the north facing window?

Thanks. Any help appreciated. (But please don't say "speak to a Building Surveyor" as that's been done hence me now sweeping wide for anyone with similar experience to see how their result compares to what I've been told.)

 

What exactly are you wanting to achieve?

 

I'm wanting to know how the building regulations are interpreted and applied to the situation outlined and what concessions can be made and who can make them (building surveyor, council, neighbour, etc).

Is it simply that the double storey addition must be at a distance from the small bedroom window at least half the height of the new wall as per 81(3)? Or can a concession be made due to the existence of the main north facing window that means consent isn't required from council for a variation to the regulations for the addition to be less than what 81(3) stipulates?

And the second question is to challenge the purpose of the regulation if the answer to the first question is yes, and potentially provide a cost effective work around to the red tape.

 

I believe there are subtle differences between them but they ultimately perform the same role of regulation enforcement.

The building surveyor is 100% correct to the letter of the regulation but I'm wondering if there are precedents or concessions not covered in the regulation which allow for the application of discretion given specific circumstances.

So I'm just wondering if anyone out there has a similar experience or knowledge on the matter.

I imagine council wouldn't want to look too deeply into until they've been provided with the application anyway. But it definitely can't hurt asking...

 

I really meant are you trying to get permission to build the grey house’s second storey extension and facing the issue of your build blocking someone else’s daylight or are you are the person in the blue house whose daylight is being blocked (potentially)?

 

TLDR, what is the objection? The proposed window is not a fire source feature as it is adequately distant from the boundary, it is obscure, high and inoperable so overlooking is not an issue.

The second storey exists, adding a window will not reduce the amount of light getting to the grey building.

If the grey building is a proposed addition, then it needs to ensure that windows do not provide a view directly into the adjoining building.

Most councils will require that the applicant provide a shadow diagram indicating the effect of the additional works if there are structural modifications/additions.

 

There is also the issue of blocking daylight from an existing window to a habitable room. May require a light court to get a Planning Permit (could require indent in new building wall). The regs show a sample diagram.

I believe the OP Is trying to say that because there is also another window then the presence of the second window shouldn’t count in the consideration of light being blocked.

 

I am the grey house getting permission for the double storey addition. The blue house has no issue with what's proposed, but I still need to go through the time and expense of submitting to council.

That's right - although I'm not so much saying it shouldn't count, I'm just curious to know if anybody has experience where a second window has changed things. I'm across the requirements of the regulation and what the options are around getting planning permission or changing the design to avoid it, but I'm wondering if anyone has an example of when a building surveyor or council were able to use their discretion and determine 81(1) and 81(3) don't apply because the window being slightly blocked is small, high and not the main window.

For example there's nothing in the reg (that I know of) that mentions how small a window needs to be before it's no longer considered a window, so who decides that? If this were a 20cm x 20cm glass brick, does 81(1) and 81(3) still apply and the existence of that single glass brick ultimately dictates where the extension is allowed to be?