Extension - are we dreaming?

Hope this is the right place to ask.

I'm currently in the process of looking to get a small extension done on the house. The extension is 2.5m x 2.5m single story and is simply pushing the double back doors out to meet the end of the kitchen and knock the wall so it creates and open space. No planning permission required. This will require an RSJ. Roofing over the extension will also be required to match what's over the kitchen area.

In terms of finish, I will be looking to add a radiator, some light fixtures, flooring (Have enough spare floor boards from when the initial floor went down).

Can anybody give any indication of what something like that will cost? I genuinely haven't a clue if I am looking at 20k, 30k, 40k etc.?

Ye it's a fairly new house as it is (5 years old). We just want to push the back doors out to meet with the back end of the kitchen. That allows us then to change the kitchen etc and actually makes a big difference given the actual sq. metre size increase.

Can I just ask why is a small extension expensive?

If anyone wants a giggle I've just had bids come back on 70sqm extension and new heat pump system for existing as well as moving a bathroom in the existing - one was just under a million and the other 700k. Obviously its not getting done.

That seems insane. We had qoute for extension in 2022 that was c. 350k to add 90sqm extension to semiD via two storey side extension and single story to back. Fully modernise existing house too. Allowing for moving out for nearly a year and no fixed price contract we went the trade up route. We got way more value I feel in sense same size house now but detached and way bigger grounds and whilst not fully modernised still modern enough. We now have way bigger garden and would have been left with postage stamp site. I just cant figure out how all these extensions are starting near us and given cost of extensions cant figure out how the prices for doer upper semi Ds are still so strong!

We're looking to get a bedroom over our kitchen and have no idea how much it could possibly cost.

The house is a two storey mid terrace with the kitchen in an extension to the rear. The extension was built before we bought the house. The bedroom would be approx 20 square metres.

It's a basic box we would be putting on, with one radiator and basic wiring for lights, sockets. There's no plumbing required other than the rad.

The only access is through the house but I know our neighbours would allow us access through their garden and over the wall.

Anyone any ballpark idea of how much this could cost?

Ah there's only three of us in the house and two bathrooms so I don't think we need one. But I'm open to being convinced otherwise.

The kitchen is on a fairly thick concrete slab, you have to step down out of the kitchen into the garden, there's a drop of about a foot. But yeah that's definitely some.thing we will have to investigate.

That's my gut feeling too. We're trying to decide if we should move or put on the extension. We like the location of the house but there are just a few annoying things that we want to sort if we decide to stay. But then again, we're not sure we could afford to move and stay in the area. Not that there's anywhere to buy that is!

We've come to the conclusion that it's probably going to be cheaper to put on the extension, add more value to the house, and that way we could look at moving in a few years time if the market calms down.