A mono stringer staircase is one of the cleanest structural elements you can put in a home. One steel beam runs up the centre. Treads mount to it on both sides. There are no side stringers, no enclosed risers, no bulky carriages hiding behind drywall. The result is a staircase that looks like it floats — but is engineered to carry the same loads as any conventional framed stair.
We build mono stringer staircases at our Burnaby shop for residential and light commercial projects across Metro Vancouver. This is a straightforward breakdown of how they work, what the design options are, and what they actually cost in 2026.
What a mono stringer staircase is
A conventional staircase has two stringers — one on each side — that support the treads from below or between them. A mono stringer uses a single steel beam, typically a rectangular hollow section (HSS) or a built-up steel plate, running up the centre of the staircase. Treads are welded or bolted to brackets that extend outward from that central beam.
The single-beam approach eliminates the visual weight of double stringers and opens up the underside of the staircase completely. You can see through it, light passes under it, and the space below stays usable. That open feeling is why mono stringers show up in so many modern custom homes across North Vancouver, West Vancouver, and newer Burnaby builds.
The structural principle is simple: the mono stringer acts as an inclined beam, transferring the combined dead load (steel, treads, railing) and live load (people walking on it) to connection points at the top and bottom of the run. The engineering is where it gets specific.
How it differs from other staircase types
Double stringer staircases use two parallel steel beams — one on each side of the treads. They’re easier to engineer because each beam shares the load, and they provide lateral stability without additional bracing. Double stringers cost less than mono stringers for the same span because the steel sections can be smaller. But they look heavier, and you lose the open-centre visual.
Floating staircases are a design category, not a structural one. A staircase “floats” when the support structure is hidden — either inside a wall (cantilevered treads) or beneath the treads (a mono stringer with minimal visible hardware). Many mono stringer stairs are marketed as floating stairs. The distinction matters because true cantilevered treads — each one anchored independently into a structural wall — are a completely different engineering scope and typically cost more than a mono stringer approach.
Conventional wood-framed staircases use dimensional lumber carriages (usually three 2x12s) to support treads and risers. They’re enclosed with drywall on the underside in most production homes. They’re the least expensive option by a wide margin but offer none of the visual openness that drives people toward a mono stringer.
Structural engineering: the non-negotiable starting point
A mono stringer staircase is a structural steel element. In British Columbia, it requires engineering by a registered P.Eng. before fabrication begins. This is not optional — your building inspector will ask for a sealed drawing, and your fabricator should refuse to build without one.
The engineering scope covers several things:
Load calculations. BC Building Code requires residential stairs to support a minimum live load of 1.9 kPa (about 40 psf) plus the dead load of the stair assembly itself. The engineer calculates the total factored load and sizes the stringer beam accordingly. A typical residential mono stringer uses an HSS beam in the range of 8x4 inches to 12x6 inches, depending on the span and rise.
Beam sizing and deflection limits. The stringer can’t just be strong enough — it also has to be stiff enough. Deflection under load needs to stay within acceptable limits (typically L/360 for residential) so the staircase doesn’t feel bouncy or produce movement at the treads. Longer spans and steeper rises require heavier sections.
Connection details. The top and bottom connections are critical. At the upper floor, the stringer typically bolts to a steel bracket embedded in or through-bolted to the floor structure. At the base, it lands on a steel base plate anchored to concrete or bolted through the subfloor into reinforced framing. The engineer specifies the connection hardware, bolt sizes, and weld details for every joint.
Tread bracket design. Each tread mounts to a pair of steel brackets (or “arms”) welded to the stringer. These brackets carry the point loads from foot traffic and need to resist both vertical load and rotational force. The engineer specifies the bracket geometry, plate thickness, and weld requirements.
Engineering fees for a residential mono stringer in Metro Vancouver typically run $1,500 to $3,500, depending on the complexity. That cost is separate from fabrication — and it’s money well spent. A properly engineered mono stringer will carry load without flex, vibration, or movement for decades.
Design configurations and their cost implications
Straight run
The simplest and most affordable mono stringer configuration. One beam, one direction, floor to floor. A straight-run mono stringer with 13–15 treads (standard for an 8- to 9-foot floor-to-floor height) is the baseline for pricing. Most of our residential mono stringer projects in Burnaby and East Vancouver are straight runs.
L-shape
The stringer changes direction 90 degrees at an intermediate landing platform. The landing is typically a steel plate or frame that’s supported independently or cantilevered from the stringer. L-shapes are common in homes where the floor plan can’t accommodate a straight run. The landing platform, additional connections, and the direction change in the stringer add $3,000 to $6,000 over a straight run.
U-shape (switchback)
The staircase reverses direction 180 degrees at a landing, with two parallel runs connected at the turn. This configuration takes up less floor area than a straight run but requires two stringer sections and a substantial landing structure. U-shapes add $5,000 to $8,000 over a straight run.
Curved
A curved mono stringer follows an arc — partial spiral or sweeping curve — with the beam bent or fabricated from segments welded to the curve radius. This is the most expensive configuration by a significant margin. The steel must be rolled or plasma-cut to the curve profile, every tread bracket is at a unique angle, and the engineering is substantially more involved. Curved mono stringers start around $30,000 and can exceed $50,000 for tight radii or multi-storey applications. We’ve built curved stringers for custom homes in West Vancouver where the staircase is the centrepiece of a double-height entry — and the budget reflects that.
Tread materials
The tread material is one of the biggest cost and aesthetic decisions in a mono stringer project.
White oak is the most popular choice across Metro Vancouver. It’s hard, stable, takes stain well, and pairs naturally with steel. Oak treads (1.5–2 inches thick, solid or engineered) typically run $200–$400 per tread, supplied and finished.
Walnut is the premium hardwood option. The rich, dark colour creates strong contrast against steel and works well in modern interiors. Walnut treads run $350–$600 per tread depending on grade and width.
Maple is lighter in colour and slightly harder than oak. It’s a good fit for Scandinavian or minimalist interiors. Maple treads sit in the $200–$350 range.
Glass treads use laminated tempered glass panels (typically 1.5 inches thick) supported on steel brackets. They create a dramatic transparency but cost $600–$1,200 per tread and require careful detailing at the bracket connection to prevent stress fractures. Glass treads are most common in high-end West Vancouver and Coal Harbour projects.
Concrete treads (precast or cast-in-place with a steel bracket substrate) give an industrial or brutalist look. They’re heavy — each tread can weigh 60–100 pounds — which affects the stringer sizing and connection engineering. Budget $300–$500 per tread.
Steel plate treads (diamond plate or smooth with anti-slip coating) are the most utilitarian option. They’re welded directly to the stringer brackets, which simplifies fabrication. Steel treads run $150–$250 per tread and suit commercial, loft, or industrial-style residential spaces.
Railing options that work well with mono stringers
The open-sided nature of a mono stringer staircase means the railing does a lot of visual work. The wrong railing can undermine the whole design.
Cable railing is the most common pairing we see. Steel posts with horizontal stainless cable infill preserve sightlines and complement the linear geometry of the stringer. Cable railing on a mono stringer staircase runs $150–$275 per linear foot installed.
Glass panel railing — either frameless with standoffs or semi-frameless with a steel channel — maximizes transparency. It’s the premium choice at $250–$400+ per linear foot, and it works particularly well on curved mono stringers where the glass panels follow the arc.
Steel rod or flat bar railing uses vertical or horizontal steel elements as infill. It’s the most visually integrated option because the railing material matches the stringer. Expect $120–$200 per linear foot.
Wood and steel hybrid railings combine a steel post-and-infill system with a wood handrail cap. This ties the tread material into the railing and softens the look. It’s popular in Kitsilano and Mount Pleasant renovations where the interior mixes warm and industrial elements.
What mono stringer staircases cost in Metro Vancouver
For a typical residential project in 2026, here are the ranges we work within:
Straight-run mono stringer, 13–15 treads, hardwood treads, cable railing, powder coat finish: $18,000–$25,000 installed. This is the sweet spot for most custom home and renovation projects in Burnaby, East Vancouver, and New Westminster.
L-shape mono stringer with landing, hardwood treads, cable or glass railing: $22,000–$30,000 installed.
U-shape (switchback) with landing platform: $25,000–$35,000 installed.
Curved mono stringer: $30,000–$50,000+ depending on radius, tread material, and railing type.
These prices include engineering coordination, steel fabrication, finishing, tread supply and installation, railing, and on-site installation. They do not include demolition of an existing staircase (if applicable), framing modifications to accommodate new connections, or permit fees.
What drives the cost
Span and rise. A longer stringer (more treads, higher floor-to-floor) requires heavier steel sections. Going from a standard 9-foot rise to a 12-foot rise can add $2,000–$4,000 in steel alone.
Number of treads. Each tread adds a bracket set, tread material, and installation time. Adding 3 treads to a run adds roughly $1,500–$3,000 depending on tread material.
Tread material. The gap between oak and glass treads on a 14-tread staircase can be $6,000–$10,000. Material choice is the single biggest variable after configuration.
Railing type. Cable railing is the most cost-effective option. Glass panels can add $3,000–$6,000 over cable for a typical residential run.
Finish. Standard powder coat in matte black or dark grey is included in our base pricing. Specialty colours, metallic finishes, or two-tone treatments add $500–$1,500. Raw steel with a clear coat (the “industrial” look) is actually more work than it sounds — the steel needs grinding, rust treatment, and a multi-coat clear finish to look good and stay protected.
Site conditions. Installing into a new-construction home with open framing and a concrete slab at grade is straightforward. Retrofitting into an occupied Kitsilano character home where the existing stair needs demolition, the floor structure needs reinforcement, and the stringer has to come in through a window opening — that’s a different scope entirely.
A recent project: Burnaby laneway house
A recent mono stringer project in a Burnaby laneway house ran $22,000 for 14 treads in walnut with cable railings. The staircase connected the main floor to a loft-style second level with a 9-foot floor-to-floor height. Straight run, no landing, powder-coated matte black steel with brushed stainless cable hardware.
The structural engineer specified an 8x4 HSS beam at 3/8-inch wall thickness. Tread brackets were 3/8-inch plate, welded full perimeter to the stringer. The walnut treads were 2 inches thick, supplied by a local millwork shop in East Vancouver, and bolted to the brackets with countersunk stainless fasteners from below.
The staircase went from signed engineering drawings to completed installation in 10 weeks. Installation took two days — one day for the stringer and brackets, one day for treads, railing, and final adjustment.
The homeowner had originally budgeted for a conventional framed stair with a drywall enclosure at around $8,000. The mono stringer was a significant upgrade in cost, but it opened up the entire ground floor visually and became the defining feature of the home.
BC Building Code requirements for staircases
The BC Building Code (and the Vancouver Building By-law, which amends it) sets minimum standards that apply to all staircases, including mono stringers:
Minimum tread depth: 235mm (about 9.25 inches), measured from nosing to nosing. Open-riser designs (no vertical piece between treads) are permitted in residential, but the gap between treads cannot allow a 100mm sphere to pass through.
Maximum riser height: 200mm (about 7.9 inches) in residential occupancies. Consistency matters — the code limits riser height variation within a flight to 5mm.
Minimum width: 860mm (about 34 inches) clear width between handrails for residential.
Guardrail requirements: Guards are required on any open side of a staircase where the adjacent surface is more than 600mm below. Minimum guard height is 900mm measured from the nosing line. No opening in the guard can allow a 100mm sphere to pass through.
Headroom: Minimum 1,950mm (about 6 feet 5 inches) measured vertically from the nosing line to any overhead obstruction.
These code requirements influence the stringer geometry, tread sizing, and railing design. Your engineer and fabricator should be working from these standards from the start — not discovering them at the permit stage.
Timeline: from design to installation
For a typical residential mono stringer project, the schedule breaks down like this:
Engineering and shop drawings: 2–3 weeks. The structural engineer sizes the beam and details the connections. We produce fabrication drawings based on the engineering and the architect’s or homeowner’s design intent.
Steel fabrication: 3–5 weeks. The stringer, brackets, base plates, and railing posts are cut, welded (C.W.B. certified to CSA W47.1), ground, and prepped for finishing in our Burnaby shop.
Finishing: 1–2 weeks. Powder coating or specialty finishing. This often overlaps with tread fabrication.
Tread fabrication: 2–4 weeks (concurrent with steel work). Hardwood treads are milled, sanded, and finished by our millwork partners.
Installation: 2–5 days on site depending on configuration and site conditions.
Total: 8–12 weeks from approved drawings to completed installation. We recommend starting the engineering conversation at least 3 months before you need the staircase in place, especially if the project has a fixed move-in or occupancy date.
When a mono stringer makes sense — and when it doesn’t
A mono stringer is the right choice when you want an open, sculptural staircase that shows its structure. It works best in spaces with good sightlines — open floor plans, double-height entries, loft-style living areas — where the staircase is visible and contributes to the architecture of the room.
It’s not the right choice for every project. If the staircase is in a hallway between two walls, a mono stringer doesn’t offer much visual advantage over a simpler double stringer or even a well-detailed conventional stair. If budget is the primary concern and the staircase is a functional connection between floors rather than a design feature, a double stringer or framed stair will serve the purpose at lower cost.
For renovation projects in older Metro Vancouver homes, the structural requirements deserve careful evaluation before committing. Reinforcing floor framing to accept the concentrated loads from a mono stringer can add $2,000–$5,000 to the project — worth it in many cases, but it needs to be in the budget from the start.
If you’re considering a mono stringer for a new build or renovation, request a quote with your floor-to-floor height, preferred tread material, and a photo or sketch of the space. We’ll give you a realistic number and timeline. You can also reach our Burnaby shop directly to talk through the options before committing to a direction.
