Extension

[SFHJ]

We are currently getting the drawings done for a rear single story extension and another option of a two story extension on the back of the house.
We are getting both drawings done so we can choose based on what we can reasonably afford. We are getting the drawings done so we can speak to builders to get an idea, we would then submit planning permission based on which one we choose to do.
Dh said he thought it would be around 20-30k for the single story and 40-50k for the two story….
Whereas I was thinking it was going to be 40-50k for the single and 80-90k for a two story.
Both options would involve moving a staircase.
Downstairs it would just be a room essentially wouldn’t involve kitchen/bathroom design. French doors not bifold to go out into the garden.
Top floor would be half the size of the downstairs, not the full width of the house if that makes a difference.
If we did upstairs there would be an ensuite involved as well.

We are living in the north east.

So my question is who is being more realistic in terms of costs?
Also would anyone else be willing to let us know cost of their extension single/2story and if that included anything such as bathroom/kitchen?

@SFHJ I'm in the NW and currently 9 months into a 2 storey extension side extension and a single storey rear extension it includes a new kitchen and ensuite. The costs are horrendous - our architect said £150k but we are looking as if the final cost will be £300k!! Raw materials costs are rising all the time; we were told originally the slates would be £1.60 each but when our builders came to order them they were quoted £6.60 each and we needed 2000. Luckily my husband found some reclaimed ones at £2 but that took time and effort but obviously worthwhile.
Sadly I think your estimates are far too low.

Eeekkk wow double more than the estimate. We do have some family links for electrician etc for internal work. Will be interested to see the estimates we get for the build! My original estimate was based more before covid hit and costs went up, but I didn’t realise how much!
Dh I think is going on when his parents did N extension about 12-14 years ago with a friend doing the build

There is an extension thread on here which it's well worth you looking at. The majority of us on it have faced delays and over spends; it's certainly not an easy time to be building!

Oh thanks will go and check that out.