Haven't a clue as to what you're trying to do from your explanation.

"Im looking to square the whole house off that the back by doing a single storyside extension.

Are you removing the gabled single story extension or planning on extending that or expanding that?

I think you mean enclosing the area where the trash cans are? If my understanding is correct you would probably put a shed roof on it. But you will probably need an architect to check whether this is allowed according to local building code and to make drawings to present to obtain a permit.

What country is the house in?

What is a "shared pitched roof" ?

Which is the "bathroom window" ?

Have you searched local architects?

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Most of your ideas are a big old NOPE from a water management and setback perspective.

Love your house! I‘m not sure what your plans are but hope you keep that old world character.

You might try https://www.houzz.co.uk/discussions for localized help.

Sorry for any confusion . im in the Uk . by square off I mean that im looking to extend the whole lower floor to the longest current point. the closest building to the camera is the shared pitch roof im reffering to as only half is ours . i have added a photo of the repitch i was referring to the window is circled.

@BeverlyFLADeziner its a semi detatched home which is why i said shared roof so where the hedge is is nextdoor. I only own half of the building.

Wanting to extend to here

The first step for you will be to find out if you can do what you plan. Then get an architect to really bring this to life and I pray you have a big $$$$$$ tree it will not be cheap.Assitions on brick homes are tricky to look good that is why often the are more like conservatories with tons of glass . So what are you planning to use the addition for?I just reread this is duplex type building so more issues will arise for sure.

I just searched on Houzz photos and it might give you some ideas ...

https://www.houzz.com/photos/query/semi-detached-home-extension

Looks like many of the extensions to semi detached homes have a flat ceiling.

I will obviously be using a local architect this is very early days i just wanted to see if its feasible or if anyone had seen anything similar before i pay for someone to create some ideas.

I know flat roof’s get a lot of hate but im still seeing so many extensions using them

I dod like this image and was wondering if something like that may work with the roof repitched

@Minardi maybe something like this

Would suggest that you add the single story addition with a shed roof but not take it any further than the face of the two story portion of the house. Some folks here are suggesting a sunroom with glass walls and roof. That would look and function quite well. There are kits that can be bought online that would probably work well.

Try looking for ideas on the Houzz UK site https://www.houzz.co.uk/

Money and planning permission are the biggest constraints here. As well as that water management. Water management is a big issue when you increase the impervious surface on a lot.