Building An Extension

[Arv]

Hello ,
I am Palnning to Build and Extension @ Back of my House.
The Rule is 40 sq meter. I am planning for A type roof. What's the max height possible? do i need to get an Architect involved?
Arv?

 

[bacchus]

Building an extension to the rear of the house which does not increase the original floor area of the house by more than 40 square metres and is not higher than the house.

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