Electrical bill of quantities from the drawing

Avenler calculates an itemised bill of quantities from the saved electrical drawing: device counts per catalogue item, cable and conduit lengths from the 3D length of the cable routes, with connection reserve and allowance, and the devices of the distribution boards. It warns about missing items, and schedules and a quotation are produced from the take-off.

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What does the bill of quantities calculate?

An electrical bill of quantities lists how much material is needed to build the plan. Avenler calculates it from the project's saved drawing, so you do not have to count devices and cable lengths by hand. The take-off contains:

• Device counts per catalogue item: the device's overriding item, otherwise the symbol's default item.
• Cable route lengths per item: the 3D length between the bend points (at ends connected to a device, including the height difference between the device and the end), plus a connection reserve per connected end (250 mm by default), plus the rise of floor links (staircases, risers), and finally an allowance (10% by default, only on items measured in metres).
• Chasing: the horizontal length of cable routes running in a chase, without allowance, if the rules include an item for it.
• Distribution boards: the enclosure and its devices, broken down by board.
• Cable by cross-sectional area: as separate items.

How does a drawing element become an item?

The take-off rules assign catalogue items to drawing elements: which item belongs to which symbol and which cable route kind (conduit or cable, system, refined by type and diameter, for cables number of cores × cross-sectional area). This is also where you set the chasing item, the allowance percentage and the connection reserve in mm. The default item, which can be overridden per device, is set on the Symbols page.

The items come from the catalogue: item number, text, unit, material unit price and standard labour time. You can import it from a CSV or XLSX file or add your own items; the shared items are managed by the administrator, and your own item with the same item number overrides the shared one.

How can you check the result?

For each line, the Breakdown shows what makes up the total (floor, source, circuit). Warnings such as “no catalogue item” point to where the fix is needed, so a missing item does not go unnoticed. Quantities are rounded to two decimals and counts to whole numbers; the calculation runs on the server, in a single place, so the take-off and the bill of materials and quotation made from it show the same values.

Schedules from the take-off

The project's Schedules menu item gives three tables from the saved drawing: the cable schedule (for each cable route the type, number of cores × cross-sectional area, the ends, the net and the order length, with totals and a floor filter), the circuit schedule (per board, “for the board door”: protection, RCD, phase, rooms) and the bill of materials. Each can be downloaded as XLSX or CSV and printed with the common title block. An electrical installation quotation can also be made from the take-off.

What it cannot do, and what to watch out for

The take-off is calculated from the saved drawing, so the drawing must be saved before the take-off, and it only sees what is on the drawing: anything not drawn does not make it onto the list. The cable length is the length of the drawn cable route; it does not replace measuring on site. A drawing element must belong to a catalogue item, otherwise the program warns you. Sizing, checks and room minimums are indicative; they do not replace the professional responsibility of the electrical designer.

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