Free tool · Building Regs

Staircase Calculator

Designing a loft conversion? Work out a staircase that actually fits — and check it against UK Building Regulations (Approved Document K) before you build. Enter your floor-to-floor height, choose a straight or turned flight, and see the rise, going and pitch update live in 3D.

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Staircase Calculator

Design a compliant staircase — straight, or with one or two turns — and check it against UK Building Regulations (Approved Document K). Drag the 3D model to rotate; the plan and checks update live.

Design to fit a space

Enter the area you have and we’ll fit a compliant staircase into it.
Number of steps (risers)
14
Staircase shape Turn 1 = one 90° bend · Turn 2 = two bends
 
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    What the terms mean

    Pitch Rise Going Height Finished floor (carpet) Loft floor / joists
    Rise per stepHeight of each step. Part K: 150–220 mm.
    GoingDepth of each tread, front to back. Part K: at least 220 mm.
    PitchOverall steepness of the flight. Part K: 42° maximum.
    2 × Rise + GoingComfort rule — should fall between 550 and 700 mm.
    HeightFloor-to-floor: from the finished floor (carpet) below to the top of the loft joists above.
    3D view — drag to rotate, scroll to zoom
    Plan view (from above)
    Guide only — based on Approved Document K for private (domestic) stairs. Winder set-out around the newel and final design must be confirmed by Building Control. Wolsten · Loft & conversion specialists
    5.0★ Google rating SafeContractor approved City & Guilds qualified 60+ years combined experience £2M public liability
    What it checks

    Every figure that has to pass Building Control.

    A loft staircase has to satisfy Approved Document K. The calculator checks the four that catch people out, live, as you design:

    Rise & going

    Each step rises 150–220 mm, with a going of at least 220 mm. We work the comfortable number of steps out for your floor-to-floor height automatically.

    Pitch

    A private staircase can’t be steeper than 42°. In a tight loft that’s the limit you end up designing against — the tool flags it instantly.

    2 × rise + going

    The comfort rule: twice the rise plus the going should land between 550 and 700 mm. Get this right and the stairs simply feel right underfoot.

    Winders & turns

    Turning the flight to save space brings tapered-tread rules. The calculator checks the going at the walking line so your winders stay legal.

    How it works

    From a measurement to a compliant design.

    1

    Measure floor to floor

    From the finished floor below to the top of the loft joists above. Pop the number in, or give the calculator your available space and let it design to fit.

    2

    Choose the shape

    Straight, one turn or two. Switch between winders and a landing and watch the footprint change in the plan and 3D views.

    3

    Check it complies

    Rise, going, pitch and the comfort rule are checked against Part K live, with a clear pass or adjust on every one.

    4

    Talk it through with us

    Happy with the design? Send it over. We’ll fold it into a fixed quote for your conversion — and handle the Building Control sign-off.

    Why it matters

    A loft staircase is the bit people get wrong.

    Turning a two-storey house into three storeys means the new stairs have to form a protected escape route, with a fixed flight, the right head height and a pitch you can actually live with. It’s the single most common reason a loft conversion struggles at sign-off.

    We’re a family-run firm — the three of us are on every job — and we’ve set out a lot of loft stairs across Bolton, Wigan and the wider North West. This calculator is the same starting point we use ourselves: get the geometry right on screen first, then build it properly and get it signed off to current regs.

    Where we work

    Loft conversions across the North West.

    Based in Westhoughton, covering Bolton, Wigan and the surrounding towns. Looking for local detail? Jump to a town page for pricing examples and recent jobs.

    Bolton → Wigan → Bury → Leigh → Chorley → Salford → Manchester → Warrington → Preston → Stockport → Oldham → Rochdale →
    Questions

    Loft staircase questions, answered.

    Does a loft staircase need Building Regulations approval?
    Yes. A loft conversion always needs Building Regs, and the staircase is a big part of it — structure, pitch, head height and a protected escape route to a final exit. We handle the sign-off as part of the job.
    What’s the steepest a staircase can be?
    For a private (domestic) staircase the maximum pitch is 42°. In a tight loft that’s usually the figure you end up designing against, which is exactly what the calculator helps you see.
    How much headroom do I need over the stairs?
    2 metres as standard. For loft conversions there’s a relaxation down to 1.9 m at the centre of the stair and 1.8 m at the side where a full 2 m isn’t achievable — the bit that makes most loft stairs possible.
    Can I use a space-saver staircase?
    Only as a last resort, and only where it serves a single habitable room. A normal fixed staircase is always preferred. The calculator’s turned options (winders or a landing) usually solve a tight space without one.
    Do you handle the Building Control sign-off?
    Yes. Everything we build is done to the current regulations and signed off through Building Control. You get a fixed quote in one working day, no deposit, and a free survey to start.

    Planning a loft conversion?

    Send us your design from the calculator and we’ll turn it into a fixed quote — in one working day, no deposit, free survey.

    Get my free quote 07482 332 817