A take-off gives you quantities — so many metres of wall, so many square metres of floor. But quantities aren't money. The thing that turns a quantity into a price is an assembly (Corbel also calls it a recipe). This guide explains what an assembly is, where your rates live, and how a measured take-off becomes a priced ASAQS bill of quantities.
What is an assembly?
An assembly is a recipe for one unit of work. It breaks a single unit down into the priced components that unit actually implies. For example, one square metre of brickwork isn't one thing you buy — it's bricks, mortar and bricklayer's labour, each in its own quantity, each with its own rate.
So a "230mm brick wall" assembly might read, per m²:
- bricks — a number per m², at a rate each
- mortar — a volume per m², at a rate per m³
- labour — an allowance per m², at an hourly or unit rate
Multiply the recipe by the quantity you measured, and you have a price. That's the whole idea: quantity × assembly = a priced line.
The rate library
Your assemblies live under Assemblies— your rate library. You don't have to build it from scratch:
- Load the SA starter library — a set of common South African assemblies to get you pricing immediately.
- Import a price list — bring in the rates your firm already uses.
- Build your own — create recipes for the way you actually work.
This is the one part of Corbel worth setting up ahead of time — but it isn't required to start measuring. You can take off a whole drawing first and add the pricing later.
Linking a recipe to a Condition
Assemblies attach to your work through Conditions. A Condition — say "230mm external wall" — carries a colour, its dimensions, and a linked recipe. When you set the Condition up (the wall wizard prompts you the first time you draw one), you pick its recipe from the rate library. From then on, every measurement on that Condition prices itself through that recipe.
From quantities to priced lines
Once Conditions carry recipes, the bill builds itself. Each measured quantity explodes through its assembly into priced components, openings deduct on the ASAQS net-wall convention, and the results collect into the Estimate · BoQtab as ASAQS sections — preliminaries, measured work, and so on. Add your markup and VAT, in rands, and you have a priced bill. When it's ready, freeze a snapshot to lock that version, then export.
Keeping rates current
Because rates live in one place, keeping them current is a single job: update a recipe or a component rate in the library, and every Condition that uses it re-prices. That's the payoff of separating what you measured (the take-off) from what it costs (the assemblies) — you can re-rate a whole project without touching a single measurement.
New to the pricing side? Start with The ASAQS bill of quantities, explained, or see how measuring feeds it in How to do a take-off from a PDF drawing.