Where to start - basement conversion

[IcarusFlies]

We bought a house with a small basement and planning permission granted for conversion of that space and extension into a proper living area.

I am considering going ahead with a similar project although I don’t think we would want to do such extensive works (ie, would require scaled back plans).

Any tips on how to even begin thinking about this? I have never managed a building project.

My first step would be to check the radon level with an actual monitoring device. Even if you are in a low risk area basements are more likely to have issues as once you're below ground the gas can come from the walls as well as the floor.

Sorry, probably not the sort of insight you were after, but it's an easy thing to check and worth it if people will be spending much time there.

Well it’s certainly insightful as wouldn’t even have occurred to me!

Assuming radon levels all good, then what…?

Are you sure? Do you really need the space? Basement conversions are horrendously disruptive, noisy, dirty, massively expensive and unpopular with the neighbours. And not particularly popular with future buyers.

Get a structural engineer in to see what works are involved. Then you need an architect to do drawings or you can contact and architect first and they will work with structural engineers. Then you need to get planning permission for the required works.
We are excavating a basement. It is partially there but we need to dig down a further metre to make it liveable.

The space would be beneficial and would help to future-proof the house. There’s no option to extend up or out. It’s not a project I’m desperate to undertake, but if we’re going to do it then better sooner rather than later, and I’m not sure how to start.

Thanks @Fretfulmum , which order did you choose (starting with architect vs structural engineer) and do you have a view on which way is better?

We got an architect first as we are having other works in the house anyway and I think that’s the best approach as they advised the structural engineer what they need to calculate for the detailed drawings.
We also had a basement company come by to take a look, so we could ask questions about the build and they were very helpful. I’m sure normal builders could do ours but we want it done properly by a basement company.