A flow reading on its own tells you almost nothing. 950 L/min at the sprinkler valve set might be excellent, or it might be half of what the system was designed to deliver. Whether a test passes depends on what it’s compared against, and in AS 1851 that reference point is called baseline data.
Baseline data is one of the most misunderstood parts of the standard. Some contractors think a building without it can’t be serviced; some owners have been told they need to recreate every commissioning record the building ever had. Neither is right. The 2012 edition, as amended, is narrower and more practical than its reputation.
This guide explains what baseline data is, which systems it actually applies to, where to find it, what AS 1851-2012 requires when it’s missing, how to re-establish it using the method Building Commission NSW publishes, and how to turn the whole exercise into legitimate, billable work.
What AS 1851 means by baseline data
Baseline data is the set of data needed at the time a system or equipment is installed to establish the performance benchmark of its approved design. It is what the system was designed and commissioned to do: the yardstick every later routine service result is measured against.
Clause 1.8 of AS 1851-2012 limits it tightly. Baseline data is only what was required by the approved design and is needed to verify a routine service activity result. It isn’t a requirement to hold every drawing and document the building ever produced.
That is a short list. Detection, occupant warning, extinguishers, hose reels and passive fire aren’t tested against flow and pressure baselines in this sense. Their routine service results are pass or fail against the activity itself.
Why it matters
- It shows degradation. Pipework corrodes and scales, valves partially close, pumps wear and water supplies change. Comparing each year’s results with the design benchmark is how you find out a system has quietly lost performance.
- It proves water supply adequacy. Annual flow and pressure testing only means something if you know what flow and pressure the system needs.
- It supports the annual statement. In NSW, further approved design documentation helps verify the performance of fire safety measures when the Annual Fire Safety Statement is prepared, even beyond what AS 1851 strictly requires.
- Regulators expect effort. ACT Fire & Rescue’s guideline acknowledges baseline data isn’t consistently available, but expects owners and maintenance providers to make “concerted efforts to compile this data where required”.
What baseline data looks like for each system
| System | Typical baseline values | Where it’s usually found |
|---|---|---|
| Sprinkler systems | Design flow and pressure required at the installation control valve, and the water supply performance the design relied on | The block plan and hydraulic data at the valve set; the hydraulic design and commissioning certificates |
| Hydrant systems | Design flow and pressure at the hydrants, and the water supply the design relied on | The hydrant block plan; hydraulic design and commissioning records |
| Fire pumpsets | The pump’s rated duty point (flow and pressure), its performance curve, and its set start pressures | The pump data plate, the manufacturer’s performance curve, and the commissioning test sheet |
| Mechanical services | The performance values the approved design sets for the relevant fire-mode features | Mechanical services commissioning reports and the approved design documentation |
Start with the schedule and the approved design
Because baseline data is tied to the approved design, the first question isn’t “what readings do we have?” but “what was this system approved to do, and under which standard?”
- In NSW, the fire safety schedule lists each essential fire safety measure and its standard of performance. It’s prepared by a registered certifier or the council, and it forms the basis of the Annual Fire Safety Statement.
- In the ACT, ACT Fire & Rescue’s guideline says the fire safety schedule must specify each fire protection system, its design standard and its installation date.
- The design standard and installation date tell you which regulations, codes and standards applied to the approved design, and therefore which baseline data AS 1851 can actually require.
If the schedule itself is missing or wrong, that’s a bigger problem than baseline data, and it isn’t yours to solve. Building Commission NSW’s guide says contractors are often the first to notice, and should explain to owners why it matters, but a fire safety contractor shouldn’t draft a fire safety schedule unless they’re also a certifier or fire safety engineer. Your role is to identify the measures you can observe on site. In NSW, councils can correct or re-issue a schedule under section 80A of the Environmental Planning and Assessment (Development Certification and Fire Safety) Regulation 2021.
Where to look for it
- Block plans. In NSW these have been required on hydrant systems since 1994 and on sprinkler systems since the 1970s, and they carry the key hydraulic information.
- Data plates on valve sets and pumps.
- Hydraulic design certificates, commissioning certificates and test sheets.
- As-built drawings and operation and maintenance manuals.
- The fire safety schedule, which states the performance standard for each measure.
- The previous contractor’s logbooks and records. Ask the owner for them, not just for the last report.
- Council, certifier or original installer files. The owner may be able to get documents that aren’t on site.
When you take over a site, ask for this in writing before the first service. Building Commission NSW’s guide says that where block plans are missing, incomplete or wrong, the contractor should first contact the owner to find out whether the information is held off site.
What AS 1851 requires when it’s missing
This is the part that trips people up. The amended 2012 edition is clear that missing baseline data doesn’t stop the service:
- Irrespective of whether baseline data is available, the routine service activity is carried out and the result recorded and reported.
- Where required baseline data is available, the result is verified against it.
- Where required baseline data is unavailable, its unavailability is recorded and reported as a non-conformance.
Building Commission NSW puts it plainly: AS 1851-2012 requires “very minimal baseline data”, and missing data usually results in non-critical defects or non-conformances, not critical defects. A non-conformance is reported to the owner within one week. It isn’t a reason to walk away from the building, and it isn’t a reason to fail every test.
Re-establishing flow and pressure data: the NSW method
Building Commission NSW’s guide includes an appendix on re-establishing flow and pressure requirements where block plans are missing or wrong. In outline:
- Gather everything you can from site (see the list below).
- Forward the information to an accredited or registered hydraulic designer for review.
- The designer develops a draft block plan and attends site to verify the information it’s based on.
- Once confirmed, keep a copy for your records, make sure the owner has a copy, install an engraved or etched copy where the relevant standard requires one, and make sure the block plan states it was prepared by a registered or accredited hydraulic designer.
The information to gather includes:
- The exact street address, and the town main connection including the stop valve location.
- The size and type of pipes used on site.
- The booster and backflow location, type and size.
- Alarm valve size, number, location and year of installation.
- Water supply proving test results, with each water supply tested independently in accordance with AS 1851.
- Tank size and infill flow rate, where relevant.
- The reduced level of the system valves and of the highest sprinkler head or hydrant valve.
- The location and size of any pressure reducing valves, with incoming and reduced pressures.
- All available pump data from the on-site fixed fire pumpsets.
- Minimum and maximum pressure and the maximum permitted flow, from the local water supply authority.
- The hazard classification of the sprinkler system.
- A copy of the fire safety schedule.
A test result isn’t design data
One trap is worth calling out. The flow and pressure you measure today tell you how the system performs now. They don’t tell you what the approved design required. Adopting today’s reading as the new “baseline” can quietly lock in a system that’s already degraded, and every future test will pass against a benchmark that was never right.
That’s why the NSW method routes the work through a hydraulic designer. Your job is to gather accurate site information and test results; establishing what the system is supposed to deliver is a design question.
A worked scenario
An illustrative example. You take over a 1990s commercial office building with a sprinkler system, a hydrant system and a diesel hydrant pumpset. The previous contractor’s reports show annual flow results but never compare them with anything. There’s no block plan at the valve set, and the pump’s data plate is legible but there’s no performance curve on site.
- Carry out every routine service activity as scheduled and record the results, including the annual flow tests.
- Record the missing baseline data as a non-conformance for each affected system, and report it to the owner within one week.
- Ask the owner, in writing, whether block plans, hydraulic design certificates or commissioning records are held off site, whether by the strata or facilities manager, the original installer or the certifier.
- Photograph the pump data plate and request the performance curve from the manufacturer or supplier using the model and serial number.
- If nothing turns up, quote a baseline capture: water supply proving tests, pump data, the site information the NSW method lists, and a hydraulic designer’s review and block plan.
- Once the designer confirms the design parameters, record them against each asset, install the block plan, and close the non-conformance.
- From the next annual test, compare every result with the confirmed baseline and with the previous year’s.
None of that stops the building being serviced in the meantime, and every step leaves a record the owner can use.
Turning it into paid work
Baseline recovery takes real time, and it’s outside a routine service contract. Treat it as the separate piece of work it is:
- Quote a baseline capture visit as its own line: site survey, water supply proving tests, pump data collection and report.
- Pass through hydraulic designer fees, or quote them clearly as a separate item.
- Include the block plan redraw and any engraved plate as distinct deliverables.
- Explain the value to the owner: it closes a recorded non-conformance, strengthens the annual statement and makes every future test meaningful.
- Start with the highest-value, highest-risk sites: sprinkler and hydrant systems with pumpsets.
Explaining it to the owner
Owners hear “baseline data” as jargon and “non-conformance” as a fault. A short, plain explanation usually does the job:
- Your system was designed to deliver a certain flow and pressure, and we test what it delivers every year.
- We don’t have the original design figures to compare against, so we can tell you what it does now, but not whether that’s what it should do.
- That missing information is recorded as a non-conformance under AS 1851. The system still works, and it’s still being serviced.
- Re-establishing the figures is a one-off piece of work. After that, every test tells you whether the system is holding its performance or losing it.
Building Commission NSW makes the owner’s case for you: it describes these records as forming part of the building asset, and says managing them well helps owners manage the cost of their maintenance obligations.
Keeping it once you have it
- Store baseline values against the asset permanently, not attached to a single job that disappears into the archive.
- Make them visible to the technician in the field at the moment they take the comparison reading.
- Keep the source documents (block plan, data plate photos, certificates) with the site.
- Hand them over if the contract changes hands. Baseline data belongs to the building, not the contractor.
- Update them when the system is modified. An alteration that changes the fire safety schedule can change the benchmark.
Common mistakes
- Refusing to test because baseline data is missing, instead of testing and recording a non-conformance.
- Failing every result on a building without baseline data.
- Treating a current test result as the design baseline.
- Chasing baseline data for systems AS 1851 doesn’t require it for.
- Doing baseline recovery for free, inside a routine service price.
- Keeping the data in a technician’s head or ute, rather than against the asset.
Frequently asked questions
Can I service a building that has no baseline data?
Yes. Carry out the routine service, record the result, and record and report the missing baseline data as a non-conformance.
Which systems need baseline data?
Under AS 1851-2012 it’s the flow and pressure performance data for sprinkler systems, hydrant systems, fire pumpsets and some mechanical service features, and only what the approved design required.
Is missing baseline data a critical defect?
Usually not. Building Commission NSW notes that missing data typically results in non-critical defects or non-conformances.
Who should re-establish it?
Gather the site information and test data yourself, then have an accredited or registered hydraulic designer confirm the design requirements and prepare the block plan.
Who pays for it?
The owner. It’s work on their building, outside routine service. Quote it separately and explain what it gives them.
Does the ACT require baseline data?
ACT Fire & Rescue acknowledges that baseline data isn’t consistently available, but expects building owners and maintenance providers to make concerted efforts to compile it where it’s required.
Sources and further reading
- Good practice guide for the inspection, testing, maintenance and repair of fire protection systems in NSW buildings, Building Commission NSW (January 2026)
- Responsibilities of building owners under AS 1851-2012, Building Commission NSW
- FSG-05 Maintenance of fire protection systems and equipment, ACT Fire & Rescue (August 2023)