Retrofit stairs, possible inadequate headroom

[Abb123]

Recently I got a local carpenter to produce a set of stairs for my house. It is to go into an existing house and has been fabricated together as one long flight of stairs, a 4 tread/step corner piece, and one stair on landing. However we are going on holiday soon so we've asked him not to install the stairs/cut hole in floor above until after we get back in a couple of weeks time.
Over the weekend I went to check it out and did some some measuring and after some measurements I had a feeling that the stairs looked a bit too long given the tight space we need to install it (2.1m along long side of L-shaped staircase and can't be longer due to proximity to kitchen door in floor above). The long stair slight has 8 steps with riser 185mm and going of 240mm. We live in England and building regs state that headroom clearance is 2.0m to step directly below. I used AutoCAD to design up stairs produced and the 2.1m hole length required and I am now certain it will not achieve the 2.0m clearance. However when I spoke to the joiner (who has 40 years experience), he says it will be fine and comply with building control.
My question is, given my uncertainty of it all (mainly joiner starts cutting holes in floor and realises he has made a mistake), what is the best way to go around this to make sure that it it is not the correct size? Is it also possible to reduce the long stair flight in length from 8 steps to 7 steps (which will in my opinion comply with 2m clearance) without starting from scratch?

 

[Wayners]

Your not under building regs? Not being inspected as not under planning or building control?
The 2m height is correct however, with some builds where it's not possible you can go a little under 2m is my understanding.
Older properties don't have stairs built to regs and if they were replaced it would have to match the old angles and step heights


.

 

[stevie888]

It's a whole lot safer checking with a tape measure (several times!) than with an expensive lump of joinery. Start again before the woodbutchery commences.

Why a 185/240: that makes a shallower than neccessary stair which is therefore longer on plan than it needs to be

 

[Abb123]

Your not under building regs? Not being inspected as not under planning or building control?
The 2m height is correct however, with some builds where it's not possible you can go a little under 2m is my understanding.
Older properties don't have stairs built to regs and if they were replaced it would have to match the old angles and step heights


.

Well yeah would I need to be under building regulations if I eventually want sell the house? It’s quite an old house (19th century) and think adjusting floor beams in floor above would be awkward.
It’s also not a like for like replacement. It’s a brand new stairs in new location in house.

 

[Abb123]

It's a whole lot safer checking with a tape measure (several times!) than with an expensive lump of joinery. Start again before the woodbutchery commences.

Why a 185/240: that makes a shallower than neccessary stair which is therefore longer on plan than it needs to be

Woodbutcjery has already commenced and has been delivered to house….

 

[johnny2007]

Don't worry.
The carpenter will have everything worked out.
Doesn't matter if clearance is below 2m; as others mentioned and I confirm, that's one thing that BCO are very flexible about.
I built loft rooms and installed staircases with 1.85 clearance with council BC full approval.
Sometimes you don't have a choice and lowering the floor below is totally over the top just to gain a few cm.