New to extension building...help

[AIMD]

We currently have a ground floor extension that we would like to build on top of to create 2 extra bedrooms upstairs (and to move the bathroom upstairs).

I’ve never planned/done anything like this. Is anyone who has done a similar extension able to give advice on the following....

*do people use architects to design extensions? Sounds silly but I’m not sure how to best layout upstairs. It’s a modest house and will be a modest extensions so wouldn’t want to spend tons on architect designs.

*we have been told the ground floor extension has foundations for a 2 story extension. How does building on top of a current ground floor extension work in terms of keeping the down stairs room (kitchen) dry and protected while building on top of it?

*any other tips or suggestions of things I might need to consider?

Thanks for any help. I’m a novice and want to get some understanding of how it all works before we progress to looking at planning permission etc.

What ever you do. Do not say you are a novice to the builder !
I would suggest an architect tho, they see where best to put stairs.
I would always go for less rooms but bigger and built in storage

That’s why I want some idea about these things before I start contacting people. 😂

We have stairs already so wouldn’t need that. But the general layout once upstairs is bigger I would need. I guess I’ll just search for local architects. Never really thought about needing an architect services before. Are they expensive?

I would use an architect, even if they just do the initial drawings. So much easier to work from and I found when we built recently the architect came up with all sorts of clever ideas to create more space and improve the look. Worth every penny.

Also catch up with the Sarah Beeny series Renovate don't Relocate. Loads of good ideas on there.

I think there is a good reason for using an architect (or Technician) in your case in as much they will be able to specify how the new build has to be 'specced to tie in with the existing extension and presumably with the original house. Two houses in our road did this - one was standard build and able to use lightweight insulated blocks but the other had to be built around welded in girders, but theirs was on a steep slope with the front dug away.

You need to ask building control what evidence you will have to supply to show the current foundations are deep enough to take another storey. They may ask for a couple of holes to be dug on the outside to expose the foundations. You can do this first before you get the plans drawn up.
I used a structural engineering company who also did plans, they put the planning permission in and submitted the plans to building control. Stairs, windows, insulation etc all have to pass building control.
Building control are very important and in my experience very helpful as well. They are part of your local council.

Thank you everyone

Fedupandlookingforchange I guess I need to contact our local building control the . Thanks I’ll do that and ask about evidence of foundations being ok. Do you
Mind me asking what the cost are roughly for a structural engineer to do the plans and liaise with building control?

Where I live it costs about £600 for building control to look at the plans and that includes the site visits and completion certificate. If you just have the site visits and completion certificate its about £550.
I think it cost me £500 for the structural engineers to draw the plans up and planning fees are on top. I just had the plans drawn up and I talked to building control and the builders but I've had a bit of practice. Once its established that you can build on the existing foundations the building control officer should liaise directly with your builder on site. You don't want a builder thats pissed off building control on previous jobs.
If an archeitect manages a job they generally charge 10% of the cost of the complete job. Structural engineers are cheaper.
Your local council website will have the planning fees but you might not need planning permission, just ring up and ask them. Building control fees will be on their website or you can just ring and ask.

Thanks it’s good to have a ball park.
Balancing up extending with waiting and moving to a bigger place.