Feature bottom steps: bullnose, curtail and D-end
Parts Glossary & Jargon Buster
Written by Scott Jones, The Stair Guys, independent staircase measuring and sourcing specialists·Last updated
The bottom step does a lot of the visual work on a staircase. It is the first thing you see and the widest point of the flight, so it is often shaped into a feature rather than left square. The three you will hear named are the bullnose, the curtail and the D-end, and they are not just looks: the shape decides where the bottom newel sits and how the handrail starts.
Bullnose
A bullnose step has a rounded, roughly semicircular return on the end, curving from the front edge back into the newel. It is the most common feature step, a softer and slightly wider start to the flight, and it can be a single bullnose on the open side or a double bullnose returning on both. The curved front is a bent or shaped riser, so it is more work than a plain square step, but it is a restrained, timeless detail rather than a fussy one.
Curtail
A curtail step is the more formal, decorative option. Instead of simply rounding off, the step wraps right around the bottom newel in a scroll shape, so the newel sits within the curve rather than at the corner of a square step. It is handed, made as a left or a right curtail depending on which side of the stair is open. The curved riser is formed either by steam-bending it round a former or by laminating thin layers around one, which is skilled work, and it is why a curtail step reads as the higher-end start to a staircase.
D-end and double curtail
Where a flight is open on both sides, or where the design calls for symmetry, the bottom step can curve at both ends rather than one. A D-end curves the step into a D shape, and a double curtail scrolls around a newel on each side. Both are more timber and more joinery again, and they suit a stair that stands in the middle of a space and is seen from more than one side.
Why the choice matters beyond the look
A feature bottom step is a design decision that ripples up the stair. It sets where the bottom newel lands, and it usually pairs with the way the handrail starts, a volute or scroll curling over the newel on a curtail, for example. It also adds cost, because a curved riser is formed rather than cut. It is worth deciding early rather than late, alongside the newel and handrail, so the foot of the stair is designed as one thing. See what drives the cost of a staircase.
Frequently asked
What is a bullnose step?+
A bullnose is a bottom step with a rounded, roughly semicircular return on its end, curving from the front edge back to the newel. It is the most common feature step, giving a softer, slightly wider start to the flight, and it can be single (one side) or double (both sides).
What is the difference between a bullnose and a curtail step?+
A bullnose simply rounds off the end of the step. A curtail goes further and wraps the step around the bottom newel in a scroll, so the newel sits inside the curve. A curtail is more formal and more joinery, and it is handed as a left or right curtail depending on which side is open.
How is a curved bottom step made?+
The curved riser is formed rather than cut, either by steam-bending the timber around a former or by laminating thin layers around one. That shaped riser is what makes bullnose, curtail and D-end steps more work, and more cost, than a plain square step.
Related guides
- Staircase parts glossary and jargon busterPlain-English definitions of every staircase part and the trade jargon you meet when buying one: treads, risers, strings, newels, spindles, nosings, winders, tenons, and the difference between bespoke and made-to-order.
- Is a newel post structural? Yes, usually, and here is whyA newel post is typically structural, not just decorative. The strings frame into it and it is notched over the trimmer at the floor opening, so it helps hold the staircase together and ties it into the structure. That is why you cannot simply remove or move one.
- How a wooden staircase is put together, and why stairs creakA traditional timber staircase is a joinery assembly, not a nailed one: treads and risers are housed into grooves in the strings and locked with glued wedges and glue blocks. Most creaks come from one of those working loose.
- Timber handrail profiles: mopstick, pigs ear, and wall vs balustrade railsHandrail profiles are the shapes a handrail is milled to. A mopstick is round and easy to grip, a pigs ear (lambs tongue) is a slim rail fixed straight to the wall, and a grooved profile carries the spindles on a balustrade. A wall-mounted rail and a balustrade rail are different jobs.
- Continuous and wreathed handrailsA continuous handrail flows over the newel posts in one unbroken line, turning corners and rise changes with curved sections called wreaths, instead of stopping at each newel. It is skilled, made-to-measure joinery, which is why it costs more than a post-to-post rail.
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