Splitting the Bill When One Works From Home and Uses More Electricity

The bill started rising and nobody wanted to say it

There's a conversation that has become surprisingly common since remote work stopped being an exception and settled in as a stable arrangement for a significant share of skilled jobs in Spain. A couple lives together in an 80-square-metre flat. One of the two works from home four or five days a week; the other goes to the office every day. The bimonthly electricity bill arrives on a Friday afternoon, up compared to the same period the year before, and above the average electricity inflation. The exact figure isn't what matters; what matters is the feeling, slight but present, in one of the two members, that they're paying for consumption they benefit from less.

Put in generic but plausible numbers, a person working from home means an added consumption of between 15 and 25 kWh a month above the household's baseline, depending on the season, the flat's insulation, the computer, the use of an external monitor, whether heating or air conditioning is needed during office hours, and whether the person has lunch at home, which adds an open fridge, microwave, oven, or hob. In winter, with electric heating, that differential can shoot up to 50 or 70 additional kWh a month, which in bill terms, at the average regulated price in 2026, amounts to between 8 and 25 additional euros a month.

In other words: we're not talking about a joke. Splitting that bill 50/50 means the person who heads out to the office every day is unwittingly subsidising a non-negligible share of the indirect labour cost of the one who works from home.

Why a strict 50/50 breaks down as soon as usage diverges

The "everything 50/50" model works reasonably well when the two people use the flat symmetrically: they head out to the office in the morning, come back in the afternoon, have dinner together, watch a series, and go to bed. In that flat, almost all the electricity consumption is shared or clearly attributable to the household. The heating goes on when both are there; the fridge is always on and benefits both equally; the washing machine is used per household, not per person.

The problem appears when usage diverges. One is at home from 9 to 6 with the external monitor on, the heating at a reasonable minimum, the laptop running, a desk lamp lit, occasionally a small heater under the desk, and the fridge opened a couple more times a day. The other person, during those same hours, is out of the house generating zero consumption at home and, paradoxically, generating consumption at their company, where they don't pay for the electricity.

The 50/50 isn't fair in this scenario. Nor is it unfair if the two people consciously accept it as part of a broader arrangement (because it's assumed that working from home brings other things to the household, like less public transport, more meals at home, the ability to receive parcels, and so on). What is clearly unfair is never having discussed it and one of the two parties thinking about it in silence.

Three sensible (and honest) ways to split it

1. The 50/50 with qualitative compensation

This is the option many couples adopt without formulating it: the 50/50 split of the electricity bill is maintained, but the person working from home takes on other household chores or expenses to compensate. For example, they do most of the shopping because they're at home, receive the parcels, manage the flat's upkeep, and the other accepts that this management load is worth the energy differential.

It works if both agree and, above all, if both put it into words. The problem is that it's rarely put into words, and then the one working from home tends to feel they already do a lot for the household's logistics, and the one going to the office tends to feel they're paying for more electricity than they consume. Both feelings can coexist without either being false.

2. The split proportional to household use

More analytical and less emotionally charged. You estimate what percentage of the flat's usage time corresponds to each member. If one is at home 12 hours a day (including sleep and morning and afternoon hours) and the other 14 hours a day (because they work from home), the split would be roughly 46-54 instead of 50-50.

The difference seems small, and in fact it is for a monthly bill: on a 90-euro monthly bill, the split changes by 3 or 4 euros. The argument in favour isn't so much the money as the sense of consistency: each pays proportionally to their use. The argument against is that it's mathematically imprecise, because not all hours consume the same (the hours with a screen and light on aren't the sleeping hours), and refining the calculation further is disproportionate to the amount at stake.

3. The remote worker's surcharge

The cleanest option arithmetically is to estimate the additional consumption associated with working from home and charge it exclusively to the remote worker. The figure is estimated conservatively: for example, 0.5 kWh per hour of the working day at home (computer + lighting + thermal load), which with 8 hours a day and 22 working days a month is roughly 88 additional kWh a month, which at the average regulated price in 2026 comes to around 18 to 25 euros a month.

That amount is borne 100% by the one who works from home, and the rest of the bill is split 50/50. It's transparent, easy to explain, easy to defend, and frees the other person from any silent resentment.

The interesting part is that this figure, in many modern countries and companies, is considered a compensation the employer should pay the remote worker for the costs associated with remote work. In Spain, collective agreements and remote-work regulation contemplate compensations, although their actual application is uneven. An informed couple can consider whether the remote worker's surcharge should be passed on to their company, not to their spouse.

The seasonal factor people underestimate

The consumption differential between working from home and not isn't linear over the course of the year. In spring and autumn, with mild temperatures and abundant natural light, the remote-work surcharge can be modest: 5 or 8 euros a month. In winter with electric heating, or at the height of summer with air conditioning on throughout the working day, the surcharge multiplies by two or three.

Ignoring this seasonality leads to recurring arguments in the extreme months. A serious couple's agreement on splitting the electricity in an asymmetric remote-work scenario should contemplate two different figures: one for mild months and another for extreme months. Or, alternatively, a surcharge proportional to actual electricity consumption, which adjusts on its own when the bill goes up.

How to log it without turning the kitchen into a spreadsheet

The most fragile part of any agreement of this kind isn't defining it, but maintaining it. A couple can sit down one Sunday, define a surcharge of 20 euros a month for the warm months and 35 for the cold ones, and apply it religiously the first two months. By the fourth month, someone forgets to note it. By the sixth month, nobody knows whether it's being applied or not anymore, and the conversation starts over.

A decent system should let you log the unequal split of the electricity bill stably, distinguish the remote-work surcharge from the rest of the common consumption, adjust it automatically every two months, and it distributes the cents by largest remainder, not by truncation, so that nobody always pays the rounding. ControlarGastos does exactly that: the couple logs the bill as a household expense, assigns the surcharge to the person who works from home as an individual expense, and the balance reflects reality without having to remember figures from memory.

Conclusion: what's really being discussed when the electricity is discussed

The conversation about who pays the electricity when one works from home is almost never just about the electricity. It is, at bottom, a conversation about how two people who share their life acknowledge that their working realities are starting to separate, and about whether that separation translates into different economic burdens that deserve to be named. A healthy couple can have that conversation and resolve it in an afternoon. A couple who avoids it, and keeps the 50/50 out of inertia, is letting a small financial resentment build up, bill after bill, until it shows up in an argument about something completely different. It's cheaper to talk about it when the difference is 15 euros a month than when it's turned into a diffuse sense of unfairness nobody can quite trace the source of anymore.