Minimum width of a stair case?

Horlock

Is there a minimum width for a staircase?

I'm considering a loft conversion and trying to draw some provisional plans. I've found all manner of requirements for stair cases, angles, maximum and minimum risers, head clearance etc. But no restrictions on width.

My logic is the narrower the better. Obviously I want to be able to walk up (and ideally carry something while walking up), but was hoping I'd get by with 80cm or possibly even 70cm (which is still wider than a narrow door). From what I can tell - standard is about 91cm.

Note: this would be a proper conversion so would need to meet building regulations.

iamcornholio

There is no minimum width requirement, but practicality comes into it. Also, dimensions of landings at the top and bottom of the flight and their usable size, may govern the practical width of the flight.

If there are no issues, then a minimum 600mm may be acceptable

But think about getting stuff up and down the stairs, and that the handrail will intrude on the space even further

System

op, what is your location? there is a minimum width in scotland

leveller2911

In England its 800mm minimum width ,maximum rise of 220mm and minimum going of 220mm ........Maximum pitch of 42 degrees but may be flexible on lofts.

If my memory serves me right any door at the top of the stairs must be 300mm back from the landing nosing and a minimum bulkhead height of 2000mm

My Building regs book is down the workshop .

jkpd

Unless regs have changed in the last few months their is no min width but as already said 600mm is the min to be practial,if it isnt practial to get required 2m headroom this can be reduced,building regs are all on the planning portal.I get all my stairs from a online company pearstairs.

willarikk

Hello for England you should consider the following;

600mm is the minimum width only if the stair allows access to one room (normally an attic stair)

If it is more than one room then the minimum width is 840mm, but 860 is more standard. These sizes ignore intrusions like stringers, skirting and newels. So from wall to handrail.
Maximum pitch (angle) is 42 degrees - unless you are replacing an existing stair, then the pitch can stay the same.
There must be a minimum of 2m headroom to bulkhead

beaker141

My loft conversion has a 600mm wide staircase, with 2 turns. Its perfectly useable, 800mm would have been brilliant. I'd say 700mm would be more than adequate.

From memory, the one thing you must do is ensure its the same width all the way up, you couldnt have 1 section wider than another which would have helped me a little.

I think I got mine from here :-

http://www.stairpartsonline.co.uk/plan1.php

lots of useful diagrams on there.

Horlock

Thanks everyone, despite a fair bit of contradictory stuff.

A bit more info as requested.
I live in England.
It is an attic conversion of a bungalow but will be more than 1 room upstairs.

The reason for asking relates to the head clearance restrictions. The plan is to go up to one side of the eaves. Because of this there will be considerable difference in height above the left and right hand sides of the staircase.

I believe the minimum on one side has to be 180cm (which is extremely close to what we have) and the other side must be at least 200cm. The 200cm is easy, we have a pitch of 42 degrees so with in an 80cm stair width the height increases by 88.8cm to 268cm. The problem is with the short side. I belive they are unbelievably strict on the 180cm rule, as such if I make the stairs 10cm narrower then the height of my shorter side increases by 11cm to approximately 190cm at worst.

My personal preference is for the wider stairs and a lower left hand side (cos this would allow me to carry things like beds upstairs), but I want to be fully armed with knowledge before getting plans rejected. My ideal would be 86cm wide with 175cm height but that will certainly be not allowed - I believe.

beaker141

Can you get a velux window in a strategic place to increase the head height in the critical area.

Also - in the head height have you factored in all the insulation needed. I had about 100mm of celotex within the new joists and still had to overboard with 37.5mm insulated plasterboard to get to the required insulation. I guess you could use the spaceage silver foil blanket type stuff - but defo check out what you need and factor it in.

My b reg guy never once got a tape measure out on mine, and I reckon if I measured it now it might be just under the 180. I'd find out who your b reg contact would be and chat it through - I think they have a bit of discretion and flexibility.

You could put 180cm on the plans, build it all and if it becomes an issue build a stud partition to pad out that wall to narrow your staircase to get the height right? I dont think it would come to this though? If it did once it's signed off you could rip the partition out?

Horlock

beaker141 wrote: »

Can you get a velux window in a strategic place to increase the head height in the critical area.

Also - in the head height have you factored in all the insulation needed. I had about 100mm of celotex within the new joists and still had to overboard with 37.5mm insulated plasterboard to get to the required insulation. I guess you could use the spaceage silver foil blanket type stuff - but defo check out what you need and factor it in.

My b reg guy never once got a tape measure out on mine, and I reckon if I measured it now it might be just under the 180. I'd find out who your b reg contact would be and chat it through - I think they have a bit of discretion and flexibility.

You could put 180cm on the plans, build it all and if it becomes an issue build a stud partition to pad out that wall to narrow your staircase to get the height right? I dont think it would come to this though? If it did once it's signed off you could rip the partition out?

Thanks for the suggestions. I don't think a Velux would work. But as you suspected I hadn't factored in the insulation - certainly not properly, I just used a tape measure and felt that heart sink as it seemed a bit low on the one side.

All things to take into account. I'll be going in for a chat. But wanted to be forwarned and armed ready to ask appropriate questions rather than just be dismissed.

leveller2911

Without seeing the job its difficult to say but have you considered having Kite winders at the top so that the stairs turn 90 degrees from the eaves? This will be an advantage for the bulkhead height. It will encroach more into your useable space but may be a possibility and would help if you have to insulate on the underside of the rafters as you will lose height.

We have a new BC officer and he is pedantic to say the least. A friend of mine is doing a 2 storey extension and he measured the bulkhead height with a tape measure 1985mm and he's made them strip out the gyproc , trimming joist etc all for 15mm........ New broom sweeps clean but the old BC guy would just walk up a staircase and know if it was right....