SFG20: what the standard actually says, and how to use it

What SFG20 is, in plain terms

Ask three contractors what maintenance your air handling unit needs and you may get three different answers, three different frequencies and three prices that cannot be compared. SFG20 exists to fix that problem. Published by BESA, the Building Engineering Services Association, it is a library of standardised maintenance task schedules covering building engineering services — thousands of schedules across more than 110 asset classes.

Its real function is translation. Maintenance obligations are scattered across statute, approved codes of practice, manufacturer requirements and industry guidance, in language written for lawyers and engineers rather than for the person planning next year's spend. SFG20 turns that into a specific list: this asset, these tasks, at this frequency, taking this long, by someone with this skillset, because of this legislation.

That last element is the one people overlook. Each schedule carries a legislation reference, so when a task is on the list you can see what drives it. That turns a maintenance schedule from a contractor's opinion into an auditable position.

The colour coding, and why it decides your budget

SFG20 classifies every task by criticality, and this is the single most useful thing in the standard for a building owner:

• Red — statutory / legal. Tasks required to comply with legislation. These are not optional and not negotiable in a value-engineering exercise.
• Pink — mandatory / business critical. Tasks required by your sector or organisation, added when a regime is tailored. Common in healthcare, food production and regulated environments.
• Amber — optimal. Function-critical work and industry best practice. Skipping it will not put you in breach of the law, but it is where reliability and efficiency actually come from.
• Green — discretionary. Non-critical maintenance. This is the genuine flex in a budget.

The practical consequence: when a maintenance budget is under pressure, the colours tell you where you can cut without creating a compliance exposure. Cutting green tasks is a business decision. Cutting red tasks is a breach. Most organisations that get into difficulty have cut without knowing which was which, because their schedule did not distinguish them.

How this applies to HVAC plant specifically

For the plant we work on, the red tasks are largely driven by regimes we cover elsewhere on this site.

F-Gas leak checking on refrigerant-bearing plant — air conditioning, VRF, chillers, heat pumps — at intervals set by charge in tonnes of CO₂ equivalent, with the 5, 50 and 500 tonne thresholds. Statutory, with record-keeping duties on the operator. See AC servicing and F-Gas.

ACOP L8 Legionella control on wet systems — cooling towers, evaporative condensers, and the water side of chilled-water and hot-water systems. Statutory, and the one most often forgotten on a building that has an evaporative cooling tower nobody thinks of as "HVAC". See chillers and chilled water.

TR19 ductwork hygiene, which carries both a fire-safety and an indoor-air-quality dimension — and in kitchen extract systems is directly a fire-risk control. See restaurant and kitchen ventilation.

Alongside those sit the amber tasks that keep plant working: filter changes, coil cleaning, condensate management, belt and bearing checks, controls verification. None of them are legally mandated in themselves, and all of them are why a well-maintained system uses less energy and fails less often.

One duty worth flagging because it sits outside the usual maintenance schedule: the TM44 air conditioning inspection, required at least every five years for AC above 12 kW effective rated output under the Energy Performance of Buildings Regulations. It is carried out by an accredited energy assessor, not by your maintenance contractor, so a fully SFG20-compliant maintenance regime does not discharge it. Details on our servicing and TM44 page.

Using SFG20 to check what you are actually buying

Most commercial maintenance contracts claim to be "SFG20 compliant". The phrase is doing very little work on its own, because SFG20 is a library — the question is which schedules from it have been applied to your building, at what frequency, and what has been left out.

Questions worth asking a contractor or a bidder:

• Which schedules have you applied to my asset list? This requires an asset register. If nobody has surveyed and listed the plant, the schedule cannot be right, because it is not derived from what is actually in the building.
• Which tasks are red, and are all of them included? A quote that omits statutory tasks to hit a price is the cheapest quote for a reason.
• Where have frequencies been reduced from the SFG20 default, and why? Reduction can be legitimate — SFG20 frequencies are a baseline that can be tuned to actual condition and criticality — but it should be a documented decision, not a silent one.
• What is excluded? Consumables, refrigerant, reactive callouts and out-of-hours attendance are the usual exclusions, and they are where contracts that look similar diverge sharply in real cost.

A defensible regime has three parts: an accurate asset register, the schedules mapped to it, and a record of what was actually done and when. The third is what you produce if an enforcing authority, an insurer or a warranty provider asks — and a contract that delivers the first two but not the third leaves you exposed at exactly the wrong moment.

Where SFG20 fits alongside everything else

It is worth being clear about the hierarchy, because these get conflated. Legislation sets what you must do. Approved codes of practice such as L8 set out how to comply. Manufacturer requirements set what keeps the warranty valid — and these can be more demanding than SFG20, in which case they win. SFG20 collates all of that into practical task schedules. Your contract is what you have actually bought.

Gaps open up between those layers. The most common: a maintenance regime built to SFG20 defaults that does not meet a manufacturer's more onerous warranty conditions, so a warranty claim is refused years later on a technicality. Worth checking the warranty terms against the schedule when equipment is specified rather than when something fails.

Getting started if you have no formal regime

Plenty of buildings run on inherited arrangements nobody has reviewed. A sensible order of work:

First, build an asset register — what plant exists, where it is, make and model, age, duty, and refrigerant type and charge where relevant. This is unglamorous and it is the foundation for everything else; every subsequent decision is guesswork without it.

Second, identify the statutory tasks that apply to those assets, and check whether they are currently being done and evidenced. This is where most buildings find their real exposure, and it is usually in the plant nobody considers — a cooling tower, a comms room split, a kitchen extract run.

Third, set frequencies against criticality and environment. A condenser in a clean office car park and one behind a fryer extract do not need the same interval, and applying a single blanket frequency across an estate overspends in one place while under-maintaining in another.

Fourth, decide what to do about amber and green tasks with an explicit view on risk and budget, rather than by default.

We build maintenance regimes on this basis across mixed commercial estates — see maintenance and PPM, and the planned versus reactive maintenance guide for the cost argument. Where the building's energy use is the concern as much as its compliance, a commercial energy audit is a useful companion exercise.

Frequently asked questions

What is SFG20?

SFG20 is the industry standard library of building maintenance task schedules, published by BESA (the Building Engineering Services Association). It covers thousands of schedules across more than 110 asset classes, and each schedule sets out the task, its frequency, expected duration, the skillset required, the relevant legislation reference and a criticality rating.

Is SFG20 a legal requirement?

No. SFG20 is an industry standard, not legislation. Its value is that it maps to legislation — tasks coloured red are those driven by statutory requirements, so the standard gives you a structured, auditable way to demonstrate which parts of your maintenance regime are legally required and which are discretionary.

What do the SFG20 colours mean?

Red is statutory or legal, pink is mandatory or business critical (added when a regime is tailored to a sector or organisation), amber is optimal — function critical and industry best practice — and green is discretionary non-critical maintenance. The colours tell you where a budget has genuine flex and where cutting creates a compliance exposure.

My contractor says they are "SFG20 compliant" — is that enough?

Not on its own. SFG20 is a library, so the meaningful questions are which schedules have been applied to your specific asset list, at what frequencies, whether every red task is included, and what is excluded. Without an accurate asset register underneath it, a schedule cannot be correct because it is not derived from the plant you actually have.

Does an SFG20 regime cover my TM44 obligation?

No. A TM44 air conditioning inspection must be carried out by an accredited energy assessor and lodged on the register, and it is a separate exercise from routine maintenance. A building can have a fully compliant SFG20-based regime and still be in breach of the TM44 duty, which applies above 12 kW effective rated output.

We build and deliver SFG20-based maintenance regimes for commercial HVAC across the UK. See maintenance and PPM for whole-building contracts, AC servicing and TM44 for the air conditioning duties specifically, and the F-Gas guide for refrigerant compliance. Or request a quote.