Extension help

[Panicatthegarden]

We are thinking of extending our second bedroom which at the minute is a bit of a box room, the previous owners did a kitchen extension on the ground floor and this is the foundation we'd be wanting to extend on top of.

We're very early in the stages of even thinking about this and I've never done anything like this so just wondered if anyone could point out anything I need to think about/ share their own experiences.

When was the downstairs extension carried out? I can’t remember when but it was a while ago that all downstairs extensions had to have foundations deep enough to take a second floor. Your local building control will be able to help you with that. Best check.

You will need to have the foundations of the downstairs extensions checked to ensure they can support the extra load. Your structural engineer and building control will advise you. Possibly will dig a couple of trial pits to check the depth.

Ahh ok don't think it's going to be quite as straightforward as I'd hoped! I appreciate the help thank you

Best case, your extension has sufficient foundations to support a second floor and you can build above it.

If the foundations aren't sufficient, there are a number of options including digging down under the existing foundations at spot points and filling underneath to make the foundations deeper. Worst case you'll need to knock down the whole wall, new foundations and build it back up.

Bear in mind that it's unlikely you'll be able to extend all the way to the edge of the existing footprint.

A loft conversion can work out far cheaper and give you a lot more square footage.

Permitted development allows 2nd storey extension if 2m from boundary. Check if that applies to your plans and whether you are have permitted development rights.

Also, whatever you do have a conversation with an architect about your plans and ask specifically about party wall agreements. I say this because my neighbour is being difficult about a very straight forward single storey extension currently.

There are a lot more restrictions than this.

Assuming that you are in England, look at Class A limitations in this document https://www.gov.uk/government/publications/permitted-development-rights-for-householders-technical-guidance/permitted-development-rights-for-householders-technical-guidance#class-a-enlargement-improvement-or-alteration

Different parts of the UK have different rules.