Creating Assemblies

An assembly is the most powerful tool in the library — once built, it produces a fresh, accurate rate every time it’s applied, using whatever current prices your products have.

When you need an assembly

You need an assembly any time a single product doesn’t capture the full cost of one unit of work. Examples:

• Brick wall per m² — needs bricks, mortar, ties, bricklayer hours, labourer hours, scaffold allowance.
• Excavation per m³ — needs excavator hours, banksman hours, disposal cost.
• Painted wall per m² — needs primer, two coats of paint, painter hours, masking allowance.

If the line is just “deliver 1 m³ of concrete”, you don’t need an assembly — a direct product price is fine.

Creating one

1. Go to Rate Library → Assemblies.
2. Click + New Assembly.
3. Fill in:
   • Name — describe the output, not the recipe. “150 mm Reinforced Slab”, not “Concrete + rebar mix”.
   • Trade — used for filtering and AI suggestions later. Pick the trade that does this work.
   • Output UOM — the unit one assembly produces. For a slab it’s m². For pipework it’s m. For a door installation it’s each. This is what the rate will be per when you apply it.
4. Save to open the assembly editor.

Adding components

For each line in the recipe, click + Add Component:

1. Pick a product from the library. Use the search — you can search by name, category, or supplier.
2. Quantity expression — how much of this product is needed per output unit. Examples for a slab assembly (output UOM = m²):
   • 0.15 — a flat 0.15 m³ of concrete per m² (assumes 150 mm slab).
   • {thickness} — references a variable so the same assembly works for any thickness. Type { in the expression field to open the variable picker.
   • 12 — 12 kg of rebar per m² (a constant).
   • 0.05 — 0.05 hours of carpenter time per m².
   • 0.15 * (1 + {waste_factor}) — material with waste added in.
3. Click Add. The component appears in the list with its computed contribution to the rate.

The assembly’s total unit rate appears at the top and updates live as you add, edit, or remove components.

Real example

150 mm Reinforced Slab (per m²)

= 0.15 m³ concrete + 12 kg rebar + 0.05 hr formwork-carpenter + 0.08 hr labourer + 5% waste

Each line is one component. The output UOM is m². When you apply this in a takeoff group with 240 m² measured, you get 240 × unit rate as the line total.

Related

• Variables — make one assembly cover many cases.
• Tips and pitfalls — naming, waste factors, deletion rules.
• Applying in the rate builder