Utilities sub-metering measures each tenant’s electricity, water, gas or heat behind a single supply meter. One utility invoice to the estate is then split into tenant-level bills. The utility recognises one customer and one meter at the boundary. Everything after that point is a contractual construct. Its legal weight rests on two things: whether the sub-meter is a verified instrument, and whether the lease says what happens to the difference.
What utilities sub-metering actually is
An industrial estate is normally one connection point. The distribution company installs its own meter at the boundary, bills the estate as a single customer, and has no contractual relationship with the individual occupiers behind it. Sub-metering is what the landlord builds on top: a meter per unit, sometimes one per plant item, and a read that turns one invoice into several.
The distinction that matters is between a meter that produces an invoice and a meter that produces information. The first is a billing instrument and carries legal consequences; the second is a check meter, useful for spotting a leak or an overnight base load, and nothing more. Estates routinely install the second and then bill from it, which works until the first tenant disputes a reading.
Sub-metering also decides what a service charge can honestly contain. A cost that is measured per unit does not belong in an apportioned pot; a cost that cannot be measured per unit does not belong on a sub-meter invoice. Estates that never draw that line end up charging some tenants twice: once through the meter and once through the estate share.
What Slovak law asks of a meter that produces an invoice
Metrology is the part of this that occupiers usually discover late. Under the Act on metrology, an instrument used to settle a payment is a designated measuring instrument, and a designated measuring instrument has to be verified. Verification is not a one-off event at installation: it expires, and the decree on measuring instruments and metrological control sets how long it lasts for each type.
Two of those periods are worth carrying in your head. A heat meter has a verification validity of four years. Water meters for cold and hot water have five years for instruments installed from 1 August 2019. The periods for electricity meters sit in the same annex of the same decree. The consequence is the same in each case. A sub-meter whose verification has lapsed is still measuring. It is no longer producing a number the payer must accept.
That is the question to ask before a lease is signed, not after a dispute. Which sub-meters serve this unit, when was each last verified, when does that verification expire, and who bears the cost and the downtime of the replacement. On a five year lease with five year water meters, the answer decides whether a renewal cycle falls inside your term.
Why water behaves differently from electricity
Water carries an extra layer. Under the Act on public water mains and public sewers the utility measures supply with its own meter. Where discharge into the public sewer is not separately metered, the volume discharged is deemed equal to the volume taken, plus water from other sources. An estate therefore pays for sewerage on a figure it never measured.
Two things follow for an occupier. First, a process that consumes water rather than discharging it is mispriced by default. So is one that discharges water it never took from the mains. Only a designated meter and a written agreement will correct either. Second, the sewerage half of the bill is derived, not read, which means a sub-metering key that splits supply correctly can still split discharge incorrectly.
Electricity has the opposite problem: it is easy to measure and easy to forget. Estate lighting, gatehouse, pumps, barriers, and increasingly charging points and cooling plant, all draw power that no unit meter sees. Those loads are legitimate estate costs, but only if the lease says so and the apportionment key is stated.
The residual difference, and who ends up paying it
Add up the sub-meters on any estate and the total will not match the supply meter. The gap has ordinary causes: distribution losses, common-area loads, unmetered plant, meters read on different days, and the tolerance of the instruments themselves. It is not evidence of anything, and it never reaches zero.
What matters is what the lease does with it. Three arrangements are in circulation. The gap is treated as a common-area cost and apportioned by floor area, which is defensible if the common loads really are shared. The gap is grossed up onto the metered consumptions in proportion, which is defensible if the losses are physical. Or the lease is silent, in which case whoever writes the statement decides, every year, without having to explain the method.
A workable clause therefore names five things. Which meters serve the unit and where they sit. Who reads them and on what date. How a failed or lapsed meter is estimated in the meantime. How the residual difference is allocated. And what right the tenant has to attend a read or to commission an independent verification. A clause that names only the first is the common case and the reason reconciliations turn into arguments.
Sub-metering and the cost lines that are growing
The stakes are rising because the loads are. Cooling plant, high-volume fans, battery storage and vehicle charging all arrived on estates that were metered for lighting and a forklift charger. Why the cooling arrived at all, and what Slovak law does to a shift once a hall passes twenty-five degrees, we work through in our post on warehouse heat. Each of them is large, each is seasonal or peaky, and each can be installed by one occupier while the meter that records it serves everybody.
That is the case to catch before it becomes a precedent. If plant serves a single unit, it belongs behind that unit’s sub-meter, and the installation consent should say so in the same sentence that permits the work. If it serves the estate, it belongs in the service charge with a named key. A third arrangement must not happen. One occupier installs the plant, the estate meter records it, and the bill is split by floor area to neighbours who installed nothing.
Sub-metering is also the quiet condition behind most green-lease drafting. A commitment to reduce consumption, share data or split the benefit of an efficiency measure is unenforceable without a meter that both parties accept. The clause and the instrument have to be negotiated together, and the instrument is the harder half.
Frequently Asked Questions
Does a landlord need a licence to resell electricity to tenants?
Reselling energy is a regulated activity in Slovakia. The answer turns on how the estate is wired, whether a local distribution system exists, and whether supply is being sold or costs recharged. That is a question for the specific set-up, and it should be settled before the first invoice.
Can a tenant refuse to pay a bill from an unverified sub-meter?
An instrument used to settle a payment is supposed to be a verified designated measuring instrument. Where the verification has lapsed the reading is not automatically void. But the party relying on it loses the presumption that the number is correct, and the burden of showing the consumption shifts back.
Who pays for replacing a sub-meter when its verification expires?
Whoever the lease says. In the absence of a clause the argument runs between ordinary maintenance, which the tenant typically bears, and keeping the premises fit for use, which the landlord typically bears. Naming the party and the cost in the schedule is a two-line job at heads of terms and an expensive one afterwards.
Should sub-metered costs sit inside or outside the service charge?
Outside, as a separate metered recharge, whenever the consumption is genuinely attributable to one unit. Mixing measured and apportioned costs in one pot makes a reconciliation impossible to check. The tenant cannot see which half of the figure a reading is meant to support.
How often should a read actually happen?
Often enough that an error is recoverable. Annual reads make every dispute a twelve-month dispute. Monthly reads, or automated readings with a monthly statement, keep a faulty meter or a misallocated load inside a period that can still be corrected without a credit note.
Working through a metering schedule, or a statement that mixes read and apportioned costs? Send it to us. We will tell you which lines are measured, which are estimated and which are neither.