How much of a job is it to increase the size of a room after foundations are in but before the actual building starts?

[GlitteringJasper]

Assuming there were no planning permission problems?

Would it be a nightmare for the builder if he was asked to do this?

Sounds a bit of a nightmare. I assume you would need to get the digger back for a day or two? Then more builder/digger driver days. Our builder charged £150 a day for himself, assume similar for digger driver? Then get the concrete wagon back, again sorry no idea how much that would be.

When we had our foundations dug, the area where the extension was to be looked much smaller than it now appears to be as built. Could this be the same for you?

The room looks tiny! Looking at the foundation I'm struggling to see how there'll be room for a sofa in it!

Have you measured it? Is it the size it was supposed to be in the drawings or the brief?

Our extension 'looked' tiny when the foundations were poured and the first courses of blocks went in. I nearly cried when I saw it - all that expense for next to nothing!

I then stood 'inside' it with a tape measure set to the length of the sofa and discovered that the space was actually a lot larger than it looked.

Ours looked tiny at this point. Think it's because the walls are a lot thinner than the area of the concrete, so in reality much more floor space IYSWIM. we have a very spacious kitchen/diner in their now

The sunroom is meant to be 14x12 feet. It looks really small though.

Just thought now would be the time to make it bigger as it'll be our main living room.

I make that 4.2m by 3.6m (or 4200mm x 3600mm as our builders would have called it). What are you hoping to fit in there? Seem plenty of room for an arm chair and sofa?