Our property maintenance guide answers this one in a single FAQ line: a good maintenance partner provides both PPM and reactive maintenance, and uses data from reactive jobs to refine the PPM schedule. That’s the correct answer, but it raises the question most property managers and landlords actually want answered — how much of each, and how do you decide?
Because “PPM vs reactive maintenance” isn’t really a contest between two strategies. Every building runs on some mix of both, whether that mix is deliberate or accidental. The buildings that run expensively are usually the ones where nobody ever decided the ratio on purpose.
What PPM Actually Covers
Proactive Preventive Maintenance is scheduled servicing and inspection carried out before anything has gone wrong — boilers, electrics, air conditioning, fire and gas systems, drainage, and the general fabric of the building. The defining feature isn’t that it’s “nice to have”; a meaningful chunk of it is legally required. Gas safety checks, EICR electrical testing, and fire system servicing all run on statutory cycles regardless of whether a building owner would otherwise prioritise them.
The rest of PPM is judgement rather than law: how often a boiler gets serviced beyond its minimum requirement, how frequently air handling units get cleaned, whether drainage gets jetted annually or only when it backs up. This is where the real cost-control decisions sit, because over-servicing wastes budget just as surely as under-servicing invites failure.
What Reactive Maintenance Actually Covers
Reactive Maintenance is the 7am phone call. A burst pipe, the lights out in reception, heating down in January, a leak after a storm. It’s maintenance that responds to something that has already broken, and no building — however well maintained — ever eliminates it entirely. Fittings fail, storms happen, tenants misuse equipment, and parts reach the end of their working life on their own schedule rather than yours.
The mistake isn’t having reactive maintenance in the mix. It’s running a building on reactive maintenance alone, which is almost always the most expensive way to operate a property once you account for emergency call-out rates, unplanned downtime, and the knock-on damage a fault causes by the time anyone notices it.
Why “Which One?” Is the Wrong Question
Framed as a choice, PPM and reactive maintenance look like alternatives. In practice, they’re a feedback loop. PPM reduces how often reactive callouts happen and how severe they are when they do. Reactive callouts, in turn, tell you where your PPM schedule is wrong — a system that keeps generating emergency callouts despite being “serviced annually” is telling you the interval, the scope, or the contractor isn’t right, not that the building is simply unlucky.
A maintenance strategy that only tracks one side of this loop is flying half-blind. Pure PPM without reviewing reactive data keeps servicing systems on a fixed schedule regardless of how they’re actually performing. Pure reactive maintenance, with no PPM at all, guarantees you’ll always be paying emergency rates for problems that could have been caught cheaply in advance.
Finding the Right Ratio for Your Building
There’s no universal split that works for every property — the right balance depends on a handful of genuine variables:
Building age and construction. As we’ve noted before, Bristol’s commercial stock in particular is a mixed bag — a single portfolio can span lath-and-plaster ceilings and lime mortar through to modern curtain walling and PV arrays, each with completely different failure patterns and servicing needs. Older or more varied building fabric generally needs a heavier PPM weighting simply because the range of things that can go wrong is wider, and some of those failure modes (damp in lime-mortar walls, for instance) are far more expensive to fix reactively than to catch early.
Criticality of the system. Not every system deserves the same servicing intensity. Fire safety, gas, lifts, and core heating in an occupied building are the systems where reactive-only maintenance is genuinely risky — to compliance, to safety, and to the building’s ability to function at all. Lower-stakes fixtures, where a fault is an inconvenience rather than a risk, can often run on a lighter PPM cycle backed by responsive reactive cover, without the same downside.
Occupancy and use. A building that’s occupied and trading every day — a shop, a restaurant, an office in daily use — has far less tolerance for unplanned downtime than a lightly used or vacant unit. Our work with hospitality clients is a good example of this in practice: a kitchen extraction fault or a fridge failure on a Saturday night doesn’t just cost the repair, it costs the night’s covers. That’s why we generally push hospitality clients toward heavier PPM on the systems that would close a kitchen, paired with fast-response reactive cover for everything else — an approach we’ve written about in more detail in preparing a pub for its busiest season.
Budget shape, not just budget size. PPM spreads cost predictably across the year. Reactive spend is, by definition, unpredictable — which makes it harder to budget for even when the total annual spend ends up similar. Clients who prefer smoother, more forecastable maintenance costs generally benefit from shifting weight toward PPM even where the raw pound-for-pound cost looks similar.
Using Reactive Data Properly
The most overlooked part of getting this balance right isn’t the initial PPM schedule — it’s what happens to the reactive job history afterward. Every emergency callout is a data point: which system, how often, what the underlying cause was, whether it was a one-off or the third time this year. Reviewed properly, that history tells you exactly where your current PPM schedule is too light, and just as usefully, where it’s heavier than it needs to be.
This is the ongoing-partnership model we run for long-term clients like our work at Wapping Wharf, where reactive maintenance and compliance testing sit alongside planned works as part of a single relationship rather than separate, disconnected contracts — the kind of setup that lets a maintenance schedule actually improve over time instead of staying static year after year.
Getting the Balance Right for Your Building
There’s no shortcut to the right PPM-to-reactive ratio beyond understanding your specific building, its systems, and how it’s actually used day to day — which is exactly why we start every maintenance relationship with an assessment rather than a standard package. Mobius delivers both PPM and reactive maintenance for commercial and domestic clients across Bristol and the South West through our FM & MEP team, covering electrical, plumbing, HVAC, gas, renewables and refrigeration, alongside the wider general building work many of our maintenance clients also rely on us for.
If you’re not sure whether your current maintenance mix is working for your building or against your budget, our full property maintenance guide is the place to start, or you can get in touch directly and we’ll talk through what the right balance looks like for your specific building.