Domestic hot water weighs heavily on an energy bill, especially since the surge in energy costs. According to ADEME, collective hot water production alone accounts for 16 to 45% of a home's total energy consumption. Whether you own an apartment in a co-ownership building or a detached house, the choice of system has a lasting impact on comfort, budget and the property's value. This article reviews the options and trade-offs to consider before deciding.
To equip or replace a hot water tank, specialist distributors such as Cedeo offer a full range of appliances, from the electric storage tank to the thermodynamic water heater. Before comparing models, you first need to understand what distinguishes collective production from individual production, because the decision-making logic is not the same.
In a co-ownership building, hot water can be produced in two ways. With collective production, a central boiler room heats the water for the entire building, then distributes it to each home via a recirculation loop kept in permanent circulation. With individual production, each apartment has its own equipment (electric tank, thermodynamic unit or gas water heater).
Collective production has a structural drawback: a significant share of the energy is lost in the distribution loop, even when well insulated. The user does not directly control their consumption, which provides no incentive to save. This is one of the reasons why collective installations consume more on average than equivalent individual solutions.
Collective hot water appeals through the pooling of upkeep and maintenance costs. But it requires a fair allocation of charges, calculated from individual hot water meters that are now mandatory and progressively remotely readable (general deadline of 1 January 2027).
More and more co-ownerships are considering full individualisation, that is, removing collective production in favour of equipment specific to each home. This approach sharply reduces shared charges and makes each occupant accountable, but it requires a vote at a general meeting, often by a reinforced majority, as well as a check of the electrical power available on the rising columns. Before any project, it is therefore better to have the operation precisely costed.
In a detached house, the owner freely chooses their system, without the constraint of a meeting. Three solutions dominate today.
For a rural owner with space and good exposure, thermodynamic or solar solutions make full sense, provided the appliance is correctly sized according to the number of occupants.
Choosing a domestic hot water system rests on a few key parameters: the number of occupants and actual needs, the nature of the property (a constrained apartment or a free-standing house), the investment budget compared with the expected savings, and the energy available on site. A home occupied year-round does not call for the same answer as a second home, where an instantaneous system or a small-capacity tank is often enough.
In all cases, the right reflex is to compare the overall cost — purchase, installation and consumption over the appliance's lifespan — rather than the purchase price alone. Equipment that is a little more expensive but economical pays for itself quickly against the lasting rise in energy costs.
Co-ownership and detached houses do not follow the same logic: the former arbitrates between collective pooling and individualisation voted at a meeting, the latter offers complete freedom of choice. In both cases, domestic hot water deserves a considered decision, because it commits comfort and budget for many years. To take the plunge, it is better to rely on equipment suited to your real needs and, if necessary, on the advice of a specialist distributor.
