How much does a BMS upgrade cost in London?

Nobody can quote a controls upgrade from a floor area. The cost of a BMS retrofit is driven by point count, access and how much of the existing field wiring can be kept.

That said, budgets are still needed before surveys are funded, so here is how the numbers are usually built up.

The five things that move the price

• Point count, taken from a real panel survey rather than the original drawings
• How much field wiring, sensors and actuators can be reused instead of replaced
• Access windows, since night and weekend possessions carry a labour premium
• Whether the supervisor and head end are being replaced at the same time
• Commissioning and witnessing scope, including any client or consultant sign off

Why per point figures mislead

A per point rate can look reassuring until you notice it excludes strategy migration, graphics, cabling remedials and out of hours working. Two quotes with the same rate can differ by a third once those are priced properly.

Ask every tenderer to break out panel works, field works, software, commissioning and access separately. Comparable structure beats a single headline number.

Where the savings actually are

Phasing an upgrade across financial years, reusing serviceable field equipment and combining controls work with planned plant replacement usually saves more than negotiating on rates. So does a proper survey, because the biggest overspends come from discoveries made after the order is placed.