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Single story side extension planning - thoughts on layout and costs??

Lunielumps
Posts: 26 Forumite

Hello!
I'm working on some preliminary single-story side extension plans - we have a 3m wide drive running run the side of our semi detached house.
our neighbour on the other side of the driveway (seperated by a fence) has a 80cm alley and then their own single story side extension.
We want to use our extension to create an open plan kitchen & downstairs toilet, and we are planning on moving the boiler, electricity fuse box & meter out of the hall and into the extension.
We also really want to maximise the 3m width as much as possible - but not sure minimum space we need to leave for guttering and footings etc beside the bourndary (fence is ours).
What i have drawn would add just shy of 20m2 to the ground floor.
Any thoughts welcome!
I'm working on some preliminary single-story side extension plans - we have a 3m wide drive running run the side of our semi detached house.
our neighbour on the other side of the driveway (seperated by a fence) has a 80cm alley and then their own single story side extension.
We want to use our extension to create an open plan kitchen & downstairs toilet, and we are planning on moving the boiler, electricity fuse box & meter out of the hall and into the extension.
Existing floor plan: https://ibb.co/0jKcMV6
Extension idea: https://ibb.co/2vR5S4Y
We also really want to maximise the 3m width as much as possible - but not sure minimum space we need to leave for guttering and footings etc beside the bourndary (fence is ours).
What i have drawn would add just shy of 20m2 to the ground floor.
Any thoughts welcome!
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Comments
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You'd be removing part of the corner of the house - this is typically an expensive way of adding m2 to a house, especially if the wall being removed is part of a gable wall (is it, or is the roof hipped?)It also appears you'd be removing a chimney breast - is there an existing stack all the way up to the roof?You'd lose access to the rear of the property - what do you use the garden for, and would you be Ok taking stuff through the house to get to the garden.A rear extension may give you more for your money, subject to how large the garden is and other factors such as level differences.1
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Section62 said:You'd be removing part of the corner of the house - this is typically an expensive way of adding m2 to a house, especially if the wall being removed is part of a gable wall (is it, or is the roof hipped?)
Sadly a rear extension isnt an option due to garden size, which also means we arent concerned about loosing external access.
The chimney stack is already removed so the chimney breast on the ground floor isn't an issue.
Yes that wall is a gable wall - what is it about opening up this stretch that would be especially challenging?
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Lunielumps said:
Yes that wall is a gable wall - what is it about opening up this stretch that would be especially challenging?
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Haven't looked at your plans, but our new extension walls are 34cm thick and the overhanging gutters are about 30cm. So that's 64cm lost before you start
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Slinky said:our new extension walls are 34cm thick and the overhanging gutters are about 30cm0
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Slinky said:Haven't looked at your plans, but our new extension walls are 34cm thick and the overhanging gutters are about 30cm. So that's 64cm lost before you startIf people considered building with a modern construction method, the walls could be less than 300mm thick. My OH also had a brick wall through on the new regs at 300mm by using solely solid insulation in the cavity.Everything that is supposed to be in heaven is already here on earth.
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Last year.
Make £2025 in 2025
Prolific £229.82, Octopoints £4.27, Topcashback £290.85, Tesco Clubcard challenges £60, Misc Sales £321, Airtime £10.
Total £915.94/£2025 45.2%
Make £2024 in 2024
Prolific £907.37, Chase Intt £59.97, Chase roundup int £3.55, Chase CB £122.88, Roadkill £1.30, Octopus referral reward £50, Octopoints £70.46, Topcashback £112.03, Shopmium referral £3, Iceland bonus £4, Ipsos survey £20, Misc Sales £55.44Total £1410/£2024 70%Make £2023 in 2023 Total: £2606.33/£2023 128.8%0 -
We did something fairly similar to this. The initial sketch I did looked very similar to yours, but in the end we decided to keep a side access like your neighbour. If the garden was smaller we'd probably have chosen to maximise the width as you have shown.
As others have said, removing the corner of the house will make things tricker from a structural engineering POV. If you can leave a section of wall there might make things easier, otherwise budget more than you think for steelwork!
I recommend chatting with a structural engineer early, before spending too much money on drawing up plans, in case there's an easy tweak you can make that will save the budget.
Cost is obviously very dependent on finishes you go for, but we spent about £100,000 on the entire project, which was finished in 2021. This included demolishing the garage and fitting out the new kitchen, utility and loo including flooring, tiles. Landscaping outside was on top of that.
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