What Ongoing Costs Should You Budget After a BDA/DAS Is Installed?

Budget roughly 2 to 3 percent of the installed system cost per year for maintenance, plus separate lines for battery replacement, the annual coverage re-test and any radio licence fees. That 2 to 3 percent is a US industry rule of thumb for active DAS, not a Singapore quotation, so treat it as a planning placeholder until you hold a maintenance quote. The costs that surprise building owners are rarely the maintenance contract itself; they are the battery change every few years and the re-test that follows any change to the building.

What does a BDA/DAS maintenance contract usually cover?

A maintenance contract normally covers a scheduled inspection visit, a check of the head-end or BDA alarms, a look at connectors and antennas in accessible areas, and a call-out arrangement for faults. One US source puts routine maintenance at US$1,000 to US$5,000 a year and remote monitoring at US$500 to US$2,000 a year, with maintenance plans typically 2 to 3 percent of system cost annually. I would not carry those dollar figures into a Singapore budget; ask the installer for a Singapore-dollar quote and see what response time it commits to.

Passive systems cost less to maintain than active ones. A passive DAS with a single BDA has few things that can fail, while a fibre-fed active DAS has remote units on every floor, each with its own power supply and alarm.

How often do the batteries need replacing?

Plan on replacing sealed lead-acid backup batteries every three to five years, and sooner in a hot plant room. Those are typical service-life figures; confirm the interval against the battery datasheet and the operating temperature of your riser or head-end room. Battery capacity is sized to carry the system through a mains failure for the hours your specification requires, as covered in the battery backup hours article, so a degraded battery is a silent failure: the system looks healthy until the day the mains drop.

What does an annual re-test involve, and who pays?

An annual or periodic re-test repeats a sample of the original grid survey readings and checks both downlink and uplink levels, alarm reporting and battery condition against the acceptance criteria. Cost scales with floor area and floor count, because the surveyor walks the same grid. Responsibility for commissioning and re-testing sits with whoever holds the obligation in your lease, tender or licence conditions, which I cover in the re-test frequency and responsibility article. Confirm the frequency your insurer, consultant or authority actually requires rather than assuming it.

Which other recurring costs get missed?

Four items turn up repeatedly:

• Radio licence fees, if the repeater or BDA transmits on an assigned frequency (verify current fees and tiers with IMDA)

• Remote monitoring or SIM subscription for alarm reporting

• Component replacement: amplifiers, power supplies, fans, and connectors that corrode in damp risers

• Re-tuning and re-testing after fit-out, partitions, or a change of radio fleet or channel plan

The last one matters most. A tenant fit-out that adds dense partitions or metallised glazing can eat into the fade margin on a floor, and the design assumptions no longer match the building.

How should you set the annual budget?

Take the installed system cost, apply 2 to 3 percent as a placeholder for maintenance, then add the re-test as a separate line, a sinking fund for battery replacement spread across the three to five year interval, and licence fees. Replace the placeholder with the maintenance quote at tender stage and write the response time into the contract. Ask each bidder to price years one to five, not just year one, so the comparison is on whole-life cost rather than purchase price.

Related questions

Is the maintenance contract mandatory? Not as a rule of its own. But a coverage obligation, a lease clause or an insurer's requirement can make periodic servicing and re-testing effectively mandatory, so check what applies to your building.

Do passive DAS systems have lower running costs than active ones? Generally yes, because there are fewer powered components to monitor and replace. The trade-off is that passive systems lose more power in cable and splitters, which limits how far they scale.

Should I budget for the head-end to be replaced? Plan for it around the ten to fifteen year mark as a rough guide, depending on manufacturer support and whether you change radio technology. Verify against the vendor's end-of-life notices.

How Suneast supports a DAS after handover

Suneast designs, installs and supports in-building radio coverage systems for Singapore buildings. Proposals state the downlink and uplink margins, so a later re-test is measured against a known baseline. For ongoing support, Suneast can provide scheduled inspection, battery and component replacement and re-testing; speak to us for a priced multi-year maintenance schedule alongside the installation quote.