Context

The single biggest source of structural estimation error, solved.

Manual concrete and formwork takeoff is where budgets derail. Intersections between elements get double-counted. Openings get forgotten. A missed column bloats the price, a duplicated beam eats the margin. Cubica extracts concrete and formwork directly from the model, per element, with overlaps and openings already netted out — auditable to the source object.

On your side

What we need

Structural Revit (.rvt) or IFC model with slabs, columns, beams, stairs and foundations
Architectural model with Rooms — optional, to tell balconies and balustrades apart from interior slabs and walls
Slab types distinguishable in the model — namely which are balconies and which are ramps; the rest is identified from geometry

On our side

What you receive

Concrete volume (m³) per element — slab, beam, column, wall, stairs, foundation
Un-formed bases (m²) as their own line item — the face bearing on ground or blinding concrete takes no formwork, and comes out separately instead of inflating the total
Formwork area (m²) per element and per exposed face, segregated by floor
Slabs split by type — floor, balcony and ramp slabs measured as separate line items, each with its own volume and formwork
Overlapping concrete deducted — the length of column crossing a slab belongs to the slab, and any pair of elements sharing the same space is detected, deducted and listed with IDs. No double counting, with the evidence alongside
"Per block × floor" views — filter the same dataset by any axis
Traceability to the BIM element — every m³ maps back to the source object
Cross-check against Revit's native volume — every quantity is verified against the volume Revit itself calculates for the element, as an extra layer of assurance
2D/3D drawing (DXF/DWG) of the geometry and formwork, included with every measurement — layers by block and line item, colour-matched to the Excel. Each element's ID is in the schedule, taking you straight back to the object in the model

Sample deliverable

Concrete and formwork, per element.

Excerpt from Betao_Cofragem.xlsx — simplified example.

Betao_Cofragem.xlsx

Reference project: residential building · 44 units · 7 floors + basement · 2 145 m² plot.

Element	Concrete (m³)	Formwork (m²)
Horizontal elements
Floor slabs	850	4 270
Balcony slabs	52	242
Beams	196	1 230
Upstands	13	142
Footings & foundations	320	735
Vertical elements
Interior retangular columns	88	706
Interior circular columns	21	216
Exterior columns	13	140
Structural walls	194	1 340
Retaining walls	78	452
Stairs
Concrete stairs	24	150
TOTAL	1 849 m³	9 623 m²

Most of these quantities come directly from the model, element by element. A few auxiliary items — such as blinding concrete under footings — aren't explicitly modelled and are calculated from the footprint area instead; they're flagged as "calculated" in the deliverable, never blended with "modelled" quantities without that distinction.

Concrete — by floor and element type m³

Floor	Horizontal	Vertical	Stairs	TOTAL
Basement	233	64	3	300
Ground floor	194	53	3	250
Floor 1	186	51	3	240
Floor 2	178	49	3	230
Floor 3	170	47	3	220
Floor 4	162	45	3	210
Floor 5	154	43	3	200
Floor 6	154	42	3	199
TOTAL	1 431	394	24	1 849

Formwork — by floor and element type m²

Floor	Horizontal	Vertical	Stairs	TOTAL
Basement	1 073	463	24	1 560
Ground floor	894	386	20	1 300
Floor 1	858	370	20	1 248
Floor 2	822	355	19	1 196
Floor 3	787	339	18	1 144
Floor 4	751	324	17	1 092
Floor 5	716	308	16	1 040
Floor 6	718	309	16	1 043
TOTAL	6 619	2 854	150	9 623

"Horizontal" groups slabs, beams, upstands, footings and foundations; "Vertical" groups columns, structural walls and retaining walls — same grouping used in the "Balance" tab.

The split between concrete, formwork and auxiliary chapters (such as blinding concrete) follows the convention documented in LNEC's Regras de Medição na Construção (CS 26) — the most widely used Portuguese reference for what belongs, and what doesn't, in each chapter. It's not a guarantee any given provider follows it; it's an external yardstick any client can ask to check against.

Group	Cubica volume (m³)	Revit native volume (m³)	Difference
Horizontal elements	1 431	1 430,6	+0,4 (+0,03%)
Vertical elements	394	393,8	+0,2 (+0,05%)
Stairs	24	24,0	0,0 (0,0%)
TOTAL	1 849	1 848,4	+0,6 (+0,03%)

"Balance" — the volume calculated by Cubica is checked, element by element, against the native volume Revit itself assigns to it. Every element that drifts from the native volume is listed with its ID and the difference, and reviewed before delivery — never included silently.

This check exists because the industry itself warns against blindly trusting a model's native quantities: the RICS BIM for Cost Managers guide notes that a BIM model's native quantity properties "do not conform to any recognised method of measurement" and need independent ratification. That's the logic behind "Balance": Revit's native volume is a starting point to verify, never the final answer.

Plausibility check m²/m³

Element	Formwork/Concrete	Status
Floor slabs	5,02	ok
Interior rect. columns	8,02	ok
Structural walls	6,91	ok
Footings & foundations	2,30	ok
Concrete stairs	6,25	ok

Every element category is checked against its own reference range, calibrated on projects already delivered — a ratio outside that range signals a modelling error (e.g. a duplicated element, open geometry) and is flagged before delivery, never silently folded into the total. This test flags statistically implausible ratios on an element that exists in the model — it does not confirm the model contains every element of the real building.

Every value is auditable back to the source element — filter by floor, by block, by typology. At each design revision it reprocesses with no manual remeasuring.

Assurance

The schedule comes with its own quality control.

A beautiful, wrong bill of quantities is worse than none. That's why the first tab of the Excel isn't quantities — it's the verdict: green, amber or red, with the list of what needs handling before the budget is closed. These checks run on every measurement, without exception.

Nothing lost in the count — every element in the model must be accounted for: measured, or excluded with the reason on record, never dropped in silence.
Double-counted concrete is detected and deducted — when two elements occupy the same space, the shared volume is counted once and the pair is reported with IDs, so you can fix the model if you want. The total you invoice is already net.
Impossible elements are flagged one by one — a 26 cm slab asking for formwork as if it were 3 cm, or an element wildly out of scale next to its peers, is reported with block, floor and ID. A per-category average hides these; a per-element check doesn't.
What sits on the ground gets no formwork — but it is recorded — the underside of footings, rafts and ramps on fill is excluded from formwork and listed separately, with its area. You see what was excluded and why, instead of it looking like a missing quantity.
Every element states why it was classified that way — alongside volume and formwork, the schedule carries the reason for each element's line item. If you disagree with a classification, you can see the rationale and argue the criterion, not the number.
Measurement by lot or by phase — the same model can be measured in separate blocks, defined by scope boxes or by the project's own grids. Useful when you invoice by lot or build in phases.

When any of these checks cannot run, the schedule says so rather than staying silent: an absence of alarms is never presented as an absence of problems.

How we measure

Diagrama isométrico: uma laje, pilares e uma viga de um modelo Revit/IFC, atravessados por um plano de varrimento translúcido

1

We start from your BIM model

We use your project's model (Revit/IFC) exactly as designed — it's the single source of data, nothing redrawn separately.

Diagrama isométrico a agrupar elementos de betão por família: laje horizontal, pilares verticais e uma escada, cada um com cor própria na legenda

2

We identify the structural elements

The engine recognises and groups every concrete element into three families — horizontal (slabs, beams, low walls, footings), vertical (columns, walls, retaining walls) and stairs — measuring the concrete volume and formwork area of each one.

Diagrama a comparar uma sapata modelada com o contorno tracejado de um elemento auxiliar calculado a partir da sua área de implantação

3

We measure element by element

Most quantities come straight from the model, piece by piece. Auxiliary items that aren't drawn, like blinding concrete under footings, are calculated from the footprint area — and the final report always tells the two sources apart.

Duas colunas de gráfico, volume calculado contra volume nativo do Revit, coincidentes sob um selo de balanço verificado

4

We check before delivery

We cross-check the calculated volume against Revit's own native volume for each element (Balance), and compare each category's formwork-to-concrete ratio with ranges calibrated on real projects (Plausibility) — catching errors before the report reaches you.

Difference

Why not by hand, and why not a generic tool

Better than measuring by hand

Where two elements meet, the shared concrete is counted only once.This applies to any pair of elements sharing the same space, not just slab with beam. Every deduction is listed so you can check it.
The stretch of column crossing the slab counts as slab, not as column.Each line item keeps what belongs to it, regardless of how the model was assembled.
No element is forgotten: it is either measured, or it appears on a list with the reason.Over 99% of elements are measured; the rest are itemised. A category never disappears in silence.
If the numbers do not add up, the takeoff is not delivered.The element-by-element sum has to match the total, to the thousandth. A pretty takeoff that is wrong is worse than none.

What generic tools do not do

If two elements occupy the same space in your model, you get the list.It is not just the deducted volume: it is the pairs themselves, with each element's ID, so you can locate them in the model and fix them at source. The modelling error stops travelling to the next project.
Formwork does not exist in the model. We build it face by face.Every face is classified one by one and the contact between elements is deducted — it is measurement, not an estimate derived from volume.
The contact area between elements is measured, not estimated.No face is left unclassified, and no contact area is entered as an estimate. What cannot be measured with confidence is flagged, not rounded.
The file we receive carries neither formwork nor the classification of each element.In the models that reach us, the fields that would say whether a wall is external or load-bearing are almost always left empty. The classification is ours, and every element comes out with the reason for its own.
Every line says why it was classified the way it was.You argue about the criterion, not the number — and the criterion is written next to the quantity.

We know exactly where our work carries weight. On a simple, well-joined model, the volumes you already have match ours. The difference that reaches the budget is in the formwork, which does not exist as a quantity in the model, in the overlaps between elements, and in the guarantee that nothing was left out.

Every number in this section comes from real measurements and can be substantiated on request. What we have not measured, we do not claim.

Scope

Cubica measures every modelled element and returns the 3D/DXF of everything measured, so each quantity can be checked against its geometric origin. The scope of the measurement is, by definition, the content of the model supplied: elements that were never modelled, or modelled incorrectly upstream, cannot be measured by any extraction method — which is why we report in writing the omissions and inconsistencies we find along the way.

The service is delivered from the model and documentation supplied, without a site visit: we measure what that information represents. Existing conditions it does not represent therefore fall outside the scope — changes made on site, deterioration, concealed elements and pre-existing works. Where a divergence between the model and what is built is identified, we reprocess the measurement on the corrected information.

Concrete & Formwork.