Extension plans

XEO25

Hi, looking for some advice regarding a ground floor extension on a 1930s semi.



We want to extend the back of the house to make a large open plan kitchen / diner. This would be the current lounge + dining room + part of kitchen + new green area in the image above, with all walls knocked down (highlighted purple below) within to make one big room.

The section of the current kitchen highlighted yellow is being knocked down (it's single brick, suspect it was a former outhouse that the previous owners knocked through and made part of the house.

To support the 2 load bearing walls (between current lounge + dining room) + the rear left to right wall of the house, I assumed we would need 2 pieces of steel forming a T shape. 

However, the floorplan above isn't to scale, and the lounge side of the house actually sticks out towards the rear a bit further than the dining room area - I've tried to show this with the red box - it's about a 2-3 foot difference. With this in mind, I can't work out what we would do with the steel for the back wall, as it's obviously not a straight back wall from left to right.

Has anyone come across this before and know what can be done? We're going to have plans drawn up, but I wanted to get an idea of what might be possible first.

Note: ignore the small red and blue squares at the top of the hall, these were from a previous image highlighting where we would change an existing door.

Thanks

twopenny

The kitchen single brick used to be a scullery in the 1930s semis where I lived.

Some people did knock them down and put a proper 2 storey extension.
Takes a fair amount of steel because you are shoring up the main wall.

FreeBear

XEO25 said:  We want to extend the back of the house to make a large open plan kitchen / diner. This would be the current lounge + dining room + part of kitchen + new green area in the image above, with all walls knocked down (highlighted purple below) within to make one big room.

To support the 2 load bearing walls (between current lounge + dining room) + the rear left to right wall of the house, I assumed we would need 2 pieces of steel forming a T shape.

For starters, a ~5.5m steel to support the upper wall is going to be expensive. Add in a Tee, and you'll want more steel in heavier sections. This is going to cost considerably more than a single ~5.5m span, and you will need beefier piers either end along with a substantial concrete base. How much steel, pier, and concrete will depend very much on what your structural engineer specifies. Only then will you be able to price up the core components.

What is your budget for this little extension ?

Doozergirl

It looks like you might have to leave something in the middle unless you're desperate to spend all of your savings on structural engineering.  Just the T is a challenge, before the consideration that your back wall isn't straight.  

Suspect you would leave in the return from the lounge projection to the dining room and then use that to support three steels coming into it.   You'd build a kitchen island around it so it's not in the way.   

You need a structural engineer in early.  

Doozergirl

Personally, I'd be looking at knocking through between the kitchen and dining room and moving the door to that room so it's a continuation of the wall between lounge and front room, creating a square space for your kitchen diner.   

Move the current door to the kitchen to the left and the toilet over to the existing kitchen, house a utility/pantry out there as well and you've bought yourself the same useable floorspace as your 'demolish and rebuild' for an absolute fraction of the cost.  

Your main kitchen run can be down the right hand side with a decent sized island facing a dining area in the existing lounge.  

If you're desperate for an extra sitting room, build a garden room.  Then you've got more floorspace for similar budget to the original plan.  Even get it signed off by building control and you're adding value.  

Whilst your existing plan might be fashionable, you're not adding much value as you're not adding any floorspace, but you could easily spend the best part of £100k.