Short definitions of the terms you meet in a CCTB specification, a bill of quantities and a BIM model — the words ArchiMind uses the way the standards do.
The Cahier des charges type – Bâtiment: the reference specification for building works published by the Service public de Wallonie. It organises the works into lots, chapters, sections and articles, each with a stable number, and is issued in dated editions. Architects derive a project’s specification from it instead of writing every clause from scratch.
The contract document that describes the works to execute: administrative clauses and technical clauses, article by article, with the quantities to price. In Belgium the technical part usually follows a reference text — the CCTB in Wallonia, the VMSW standard specification for social housing in Flanders.
The project-specific version of the specification: the reference text reduced to the articles the project needs, the choices made where that text leaves options open, the project’s own additions, and its quantities. It is the document tenderers price.
The top level of the CCTB structure, numbered T0 to T9 by trade or phase — T1 groundworks and foundations, T2 superstructures, T3 roofs, and so on. Every chapter, section and article of the specification sits under one lot.
The two levels between a lot and its articles. A chapter groups one family of works (24 Timber superstructures); a section groups one type of element within it (24.1 Timber structural elements). Their numbers form the first parts of every article number below them.
The smallest unit of the specification and the one an architect actually specifies: one type of work or product with its own number (24.13.1a) and its own text. A project’s specification is a selection of articles, adapted where the reference text leaves choices open.
The hierarchical reference of an article: chapter, section, sub-levels and a letter, up to six levels deep (24.13.1a). The same number names the clause in the specification, the line in the bill of quantities and the item in the tender — which is what keeps the three documents coherent.
The standard subdivisions inside a CCTB article. Description says what the work includes; Materials sets the products and their requirements; Execution says how the work is carried out; Measurement says how the work is measured and paid. A project may adapt each part or add its own.
The itemised list of the works to price: one line per article with a quantity, a unit and a measurement type. In Belgium it is part of the tender documents and must agree with the measurement clauses of the specification it accompanies.
One line of the bill of quantities: an article number, a description, a quantity, a unit and the measurement type that says how the quantity is priced. Several line items can refer to the same article when the work occurs in different forms or locations.
The codes that say how a line item is paid. QF, lump-sum quantity: the stated quantity is contractual and paid as such. QP, presumed quantity: an estimate, settled on the quantity actually measured. PG, global price: one price for the whole item, without a quantity. SAJ, sum to justify: a provisional amount settled against invoices. PM, for the record: an item listed without a price because it is paid under another one.
What a quantity counts: metres, square metres, cubic metres, kilograms, pieces, hours. A lump sum with no physical quantity takes the unit “fft” (forfait). The unit is not the measurement type: a quantity in m² can be lump-sum (QF) or presumed (QP).
Industry Foundation Classes: the open exchange format for building models, standardised as ISO 16739 and maintained by buildingSMART. An IFC file carries the model’s elements with their geometry, classification and properties — which is what lets quantities be read from a model instead of measured on drawings.
Building Information Modelling: designing with a data-rich 3D model whose elements know what they are — a wall of a given type, a slab of a given thickness. The model becomes the shared source for drawings, quantities and coordination between disciplines.
A point where the reference article offers alternatives — a material grade, a finish, a performance class — and the project must pick one. A choice left unresolved is a gap in the specification: the contractor cannot price it, so it has to be settled before the document is issued.
The words “or equivalent” placed after a brand or type name, so that a competing product meeting the same requirements can be offered. Usual in public procurement specifications, where a brand named on its own would narrow the competition to one supplier.
The dated version of a reference specification, such as an edition of the CCTB. Numbers and wording can change between editions, so a specification states the edition it follows, and a citation taken from another edition is an inconsistency to correct before issue.
The Vlaamse Maatschappij voor Sociaal Wonen, the Flemish social housing agency, since 2023 part of Wonen in Vlaanderen. Its standard specification for social housing, still known by the VMSW name, is the reference text for that sector in Flanders, as the CCTB is for building works in Wallonia.
The reference specification of the Service public de Wallonie for road and public-space works: the road counterpart of the CCTB, used for roads, sewers, paving and outdoor works. A project mixing a building and its surroundings can follow both.
The European standard for concrete — specification, performance, production and conformity — as adopted in Belgium, with the national supplement NBN B 15-001 fixing the Belgian choices. A concrete article cites it to define the concrete by its strength class, exposure classes and consistence.
The procedure in which contractors price the specification and its bill of quantities; the offer they return is the priced bill of quantities. The quality of both documents decides how comparable the offers are and how many disputes follow on site.