Feasibility tools · Interactive

See it before you build it.

Three conceptual explorers built to show how the trade-offs move. Every number lists its assumptions — and what it ignores.

See the depth trade-off in seconds.

Drag a span and choose a floor system. The depth moves with you. It won't design anything — it'll show you which system leaves you headroom and which one quietly costs you a storey.

Start from a building type

Grid spacing X (clear span)8.0 m

Grid spacing Y (bay width)8.0 m

Occupancy loadStandard office

Floor system

Structural depth

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Floor-to-floor

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Deflection limit

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WHAT THIS DOES — AND DOESN'T — DO

Each floor is sized to Canadian codes by Sense Engineering's floor-depth engines, not a span/depth ratio: glulam beams to CSA O86:24 (24f-E D.Fir-L), steel W-sections to CSA S16-19 (non-composite under the CLT, or composite with a Canam steel deck), and a concrete slab on columns to CSA A23.3-19 (flat plate, drop panels or post-tensioned) [3][4][5][6]. Loads: finishes and services 0.5 kPa plus partitions 1.0 kPa, live load 1.9 / 2.4 / 4.8 kPa, combined as 1.25D + 1.5L and 1.4D [6]. Structural depth is the deepest member. For glulam and steel W-section w/ CLT it is the beam alone: the CLT deck and 50 mm topping sit on top, add their self-weight, and count in floor-to-floor so all four systems compare like-for-like. For the composite floor it is the slab plus the deepest beam; for concrete, the slab, plus the drop panel at the columns where one is used. Floor-to-floor assumes a 2.6 m clear height and a 400 mm services zone, with services running inline (between the downstand beams, or between the drops), so the zone is the greater of the two, not the sum. Every system is drawn to one scale. Glulam is sized without a fire rating; steel assumes applied fire protection. Not checked: floor vibration (steel, W-section w/ CLT and glulam), connections, and corner columns. A feasibility sketch, not a design. See Basis & sources ↓

See the carbon before you pour it.

Structure is where a building's embodied carbon is won or lost. Choose a system and size a building — we'll estimate its structural embodied carbon (A1–A3) against a concrete baseline, live.

Start from a building type

Floor area / storey350 m²

Storeys2

Structural system

ESTIMATED STRUCTURAL EMBODIED CARBON

864tCO₂e

vs concrete baseline−58%1,182 tCO₂e avoided

WHAT THIS DOES — AND DOESN'T — DO

Carbon — illustrative A1–A3 intensities (kgCO₂e / m² GFA): mass timber ≈ 180 · timber–hybrid ≈ 280 · steel ≈ 380 · concrete ≈ 430, consistent with embodied-carbon guidance from the Institution of Structural Engineers (IStructE), LETI and the University of Bath ICE database. Peer-reviewed life-cycle studies report mass-timber structural embodied carbon roughly 20–60% lower than concrete, depending on system and boundaries [1][2]. Cost — indicative structural cost (CAD / m² GFA), structure only; excludes foundations-to-finishes, site and market variation. How height changes it — the rates above describe a three-storey reference building; taller adds to them and lower subtracts. For carbon the step is +5 kgCO₂e/m² per storey, quoted from the Institution of Structural Engineers, which reports frame capital carbon of 145–170 kgCO₂e/m² at three storeys rising to 205–235 kgCO₂e/m² at fifteen [9]. It is applied equally to all four systems because that source gives a single rate. For cost there is no equivalent published figure, so the step is sized from SCI/BCSA's frame-weight bands (50–60 kg/m² low-rise against 75–90 kg/m² high-rise) and is a modelling choice, not a code rule. Both steps are shown in the working line above, so what was applied is always visible. IStructE puts structure-only capital carbon at 100–600 kgCO₂e/m² and whole buildings at 350–800 [9] — every figure this tool produces sits inside that structural range. All figures are for early-stage comparison — a project-specific assessment models the actual quantities, material EPDs, biogenic carbon and a real cost plan. See Basis & sources ↓

Six systems, ten criteria, one score.

Rate each system 1 (worst) to 5 (best) per criterion, switch criteria on or off, weight the ones that matter, and add a cost rating. Defaults are Sense's engineering view for a Metro Vancouver site — edit anything.

Every option sits on the same base: a reinforced-concrete podium at Level 1 over one level of parking basement. Only the structure above the podium changes, so the ratings compare the upper floors and how they load the podium, foundations and basement box.

Storeys above grade (with podium)

Major occupancy

Encapsulation ratings

Ranking

The matrix

Score = Σ(weight × rating) ÷ Σ weight

1 worst 2 3 4 5 best

Criterion · weight

1 (worst) to 5 (best) — click a segment to rate, its left half for a half point A tinted cell leads its criterion Switched-off rows are greyed and left out of the score

How high can each system go in BC?

BC Building Code 2024, Revision 1 (in force 10 April 2024) · adopted in the Vancouver Building By-law 2025 (in force 15 Sept 2025)

Construction	Storey / height limit	Encapsulation required	Timber that may stay exposed	Also note
Light wood framecombustible construction · Art. 3.2.2.50 (C) / 3.2.2.58 (D)	6 storeys and 18 m to the top floor	Rated gypsum assemblies throughout (typically 1 h floors and walls)	None — structure is concealed	Sprinklered; limits on combustible cladding and building area per storey
EMTC, 0-min tierTable 3.2.2.93	8 storeys / 34 m (Group C) · 9 storeys / 38 m (Group D)	None on suites; 25 min (1 × 12.7 mm Type X) in corridors, exits and shafts; concealed spaces protected	Walls, ceilings, beams and columns	New in 2024 — the tier most 6–8 storey podium schemes fall in
EMTC, 50-min tierArt. 3.2.2.48 (C) / 3.2.2.57 (D) · 3.1.6.4	12 storeys / 42 m	50 min = 2 × 12.7 mm Type X (or 38 mm topping on the floor top)	Beams, columns and walls up to 35 % of the suite's perimeter wall area; ceilings 10 % (FSR ≤ 150) or 25 % (FSR ≤ 75); a fully exposed ceiling if beams/columns ≤ 20 % and walls are fully encapsulated	Combustible cladding limited to small, separated areas
EMTC, 70-min tierTable 3.2.2.93 · 3.1.6.4.(9) · 3.1.6.9	18 storeys / 76 m (Groups C and D)	70 min = 2 × 15.9 mm Type X on all timber; 50 min allowed on the top side of floors	None	Non-combustible cladding above 12 storeys; stair and elevator shafts above 55 m in EMTC or concrete
Non-combustibleconcrete, structural steel, steel stud	No storey cap	Inherent ratings (concrete) or fire protection on steel (spray, intumescent, gypsum boxing)	n/a — steel columns in the hybrids still need their own protection	High-building provisions (3.2.6) once the top floor is above 18 m (Group C) or 36 m (Group D; 18 m where the exit-width test in 3.2.6.1 fails)

EMTC = encapsulated mass timber construction. Storeys are counted above grade, so the parking basement does not count but the podium level does. Every EMTC building must be sprinklered and floors carry a 2-hour fire-resistance rating. Steel columns or steel-stud walls used with CLT floors are non-combustible construction and may be combined with EMTC in the same building (3.2.2.93.(2)). Confirm the applicable edition, occupancy mix and any alternative solutions with the authority having jurisdiction and a code consultant before relying on these tiers.

WHAT THIS DOES — AND DOESN'T — DO

What it is — a weighted decision matrix, not a calculation. It records an engineering judgement as numbers so the trade-off is visible and arguable: every rating is 1 to 5, every weight is yours, and the score is simply Σ(weight × rating) ÷ Σ weight. Change a weight and the ranking can flip — that is the point of it. The defaults — Sense's own view for a six-storey residential scheme on a Metro Vancouver site: an RC podium at Level 1 over one parking basement, with only the structure above the podium changing. Each default rating carries its reasoning; open Show rationale to read it. Cost — the cost ratings are relative placeholders. Confirm them with a quantity surveyor before quoting. Cost is switched off by default so it never quietly drives a ranking. The code tiers — storey and encapsulation limits are read from BCBC 2024 Revision 1 as adopted in VBBL 2025, with the article numbers shown above. They are a first screen, not a code review: occupancy mix, building area, exiting, alternative solutions and the authority having jurisdiction all decide the real answer. What it ignores — geometry, site, wind and seismic demand for the actual building, soil and water-table conditions, procurement and market pricing, programme risk and supply. Nothing here is a design, a quotation or a code opinion.

Basis & sources

Every figure, referenced.

The estimators on this page use published, reputable benchmarks and code values. Here's exactly where they come from.

[1] Institution of Structural Engineers (IStructE), How to Calculate Embodied Carbon (2nd ed.); and LETI, Embodied Carbon Primer — methodology and benchmark A1–A3 intensities for structural materials.
[2] Peer-reviewed life-cycle assessments comparing mass-timber and concrete structures — reported embodied-carbon reductions of ~20–60% (e.g. systematic reviews in Sustainability / Buildings, MDPI; USDA Forest Products Laboratory comparative LCA).
[3] Canam — LSD composite steel deck data sheets P-3606 / P-3615 and P-2432 (unshored spans and slab weights), used for the composite floor.
[4] AISC Shapes Database v16.0 (metric W-section properties, matched to CISC designations and spot-checked against the CISC Handbook).
[5] Kalesnikoff CLT 5-ply layup (APA PR-L332(C)), via Timber Navigator; and StructurePoint's CSA A23.3-14 worked examples (flat plate, flat slab with drop panels), which the concrete punching checks reproduce.
[6] National Building Code of Canada 2020 (NRC) and CSA O86:24 / S16-19 / A23.3-19 (CSA Group) — loads, load combinations, L/360 and L/240 deflection limits, and design of timber, steel and concrete members.
[7] U.S. Environmental Protection Agency — Greenhouse Gas Equivalencies Calculator (4.6 tCO₂e per typical passenger vehicle per year), used for the "cars off the road" comparison.
[8] University of Bath — Inventory of Carbon & Energy (ICE) database, embodied-carbon factors.
[9] Institution of Structural Engineers (IStructE), Carbon footprint benchmarking data for buildings, The Structural Engineer (2020) — frame capital carbon 145–170 kgCO₂e/m² at three storeys rising to 205–235 at fifteen (approx. +5 kgCO₂e/m² per storey); structure-only range 100–600 kgCO₂e/m², whole building 350–800.

Cost figures are indicative early-stage benchmarks and vary by market — not a quotation.