Joining my new 6m rear extension to neighbour's existing 3m rear extension

[Alphatiger]

(1) I understand if I get a partywall agreement I can join my rear extension onto the neighbours, however my main query is that his rear single story extension which was built 13yrs ago goes over our land by about 20cm, so can I just build a single leaf blockwork extension rather than doing double leaf as it will eat into our extension size? Is it building control's decision?

(2) His extended roof is flat, ideally we would have perferred slightly pitched tile. Can you advise if my extension should match his in terms of height and type? I am also having a dormer put on so I guess a flat roof is better if I ever need access to roof for maintenance/gutter cleaning using a ladder?

 

[noseall]

I'd like to see what your designer has come up with first. Any piccies?

 

[Alec_t]

Is your house currently attached to or detached from the neighbour's house? If detached, linking the two could adversely affect the property price of both.

 

[Alphatiger]

Hi it's an old semi. I attach a photo of the rear garden where the rear new L-shape 6m extension will go. You can see the neighbour's extension already there and over-hanging our garden slightly. I don't know how he achieved that extension 15yrs ago as an old widow used to live in our house - I doubt he will show his old party-wall agreement drawings. Many thanks in advance for your advice...

 

[Footsoldier888]

Any Party Wall agreement has to be declared in the sellers form so it is worth checking to see if there was one. If there isn't then your position if anything is better.

However I wouldn't worry about the exact line of boundary too much as you have to build 15cm inside your foundations anyway. You can only attatch if you are doing the same thing re extension, I doubt you will be having a flat roof like that.

I can't help wondering where the drainage is on your neighbours extension. Hopefully the water is not flooding over to your property!

 

[RichA]

Do the pictures and plans match? Is that an old photo? Where is the 'old extension' mention in the plans?