Access Control System Design & Door Schedule Calculator (Excel)

This Excel workbook is a working aid for access-control / ACS projects. It helps an ELV designer or estimator keep a per-door schedule and turn it into device totals, controller count, central power-supply and battery sizing, cable lengths and a linked bill of quantities.

On the Inputs sheet you enter project details and the system assumptions: 12 or 24 V, doors per controller, spare controller capacity, standby hours, battery size, PSU rating, headroom, charger allowance and cable slack. Editable current libraries list typical standby and active milliamp figures for readers, locks and REX devices, at the selected system voltage.

The Door Schedule records, for each door, the location, door type, entry and optional exit reader, lock type, REX, number of door contacts, power source and one-way cable run. Currents are looked up from the libraries. A power-source rule includes or excludes reader and lock loads from the central PSU and battery totals (Central PSU, PoE, Lock PSU separate, or Local PSU).

The Design Summary totals doors, readers (by type), locks (by type), REX devices and door contacts; sizes controllers with ROUNDUP(doors × (1 + spare) ÷ doors per controller); calculates required battery Ah (standby current × hours × safety factor), parallel banks and total batteries; sizes the central PSU with headroom and a peak-load check; and reports slack-adjusted cable lengths for reader, lock, REX, door-contact and controller comms cables. The BoQ sheet links those quantities, lets you type unit rates, and calculates line amounts, category subtotals, contingency, tax and a grand total. Spare rows are provided for site-specific items.

Yellow cells are inputs; blue cells are formulas. No macros. Works in Microsoft Excel, LibreOffice Calc, Google Sheets and WPS. Sample data and rates for a fourteen-door office example are placeholders only and are not price advice. This is a working aid, not a certified design. Confirm currents, cable size, PSU and battery selection, fire-alarm lock release and any life-safety interlock against the project brief, local codes and manufacturer specifications.

Prepared by Chen Yu, an ELV / intelligent-building engineer with 25+ years of design, BoQ and commissioning experience.