Garden room need planning permission??

[mrmcrae]

So I am looking to replace an ageing garden shed with a 3x4 garden room however, I’m not sure if i need planning permission…

 

Currently the shed fits between the house and the garden wall (basically the front and the roof has been built and the other 3 sides are the house wall and the garden walls)

 

I have checked the planning portal and I don’t believe i do but where I want to put it is leaving me with some doubts.

 

From the outside it might look like an extension as I want to attach it to the side wall of the house but its not and from my understanding is that the width of an extension must not exceed 50% of the width of the main house.  This garden room i think might just be over 50% but as its not an extension so does the same rules apply?

 

Although the depth on the attached plan says 2.5m, I’m looking at pushing it to 3m.  I will probably push the height to just under 2.5m which i believe is the max due to being with 2m of a boundary which in this case it is.

 

What’s your thoughts?