Roof Height Limit to Window for PD [Drawings]

[GateBeam]

Hi,

Does the maximum height for a single story rear extension using a gable or hip roof have to below the existing window?
Or can the I go above the window as long as I stay under the 4m PD rules?
I can't find anything on the planning portal unfortunately.

For example , in this drawing, would the maximum height be the "window height" or the "Bullnose Brick External Sill Height" or Can I go above these lines as long as I am under 4m?

Thank you.

 

[^woody^]

The dimension is the only criteria.

 

[catlad]

You can put a smaller window in and higher the cill

 

[GateBeam]

@^woody^

I'm not quite understanding what you mean. The dimension for which part? Thanks.

 

[^woody^]

The 4m dimension. The window is irrelevant.

 

[GateBeam]

@catlad

The extension's height is OK because the ceiling height is 2.4m.
So there's no need to put a new window in the existing building as the extension height can be adjusted.
So does the extension have to below the window?

 

[GateBeam]

@^woody^
I see. The reason for asking was because the proposed extension roof's height could block light to the existing window.
But now I go as you suggested and take advantage of the full 4m and ignore the window

 

[Nakajo]

How will it block 'light'? Where I live most of the 'light', comes from the Sun, which, for most of the day, is above me.

 

[GateBeam]

@Nakajo
Haha, my main reasoning was that I assumed there would be a rule similar to the 45 degree / right to light rule for any window that may become covered/shadowed by new buildings. But I now know there is not, so all good.