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Thermal billing

Thermal meter on  radiator

This is a question relevant mainly to Italy and so needs a few words of explanation for any international reader.

Apartment blocks in Italy are for the most part built with centralised heating systems, by which a large central boiler of several hundred kilowatts thermal power provides hot water to all the apartments in the building.

Until recently the annual running costs (mainly fuel costs) associated with the heating system were shared between owners based on the floor area of their respective properties. There were a number of advantages to this solution (for example it's simple), but the main disadvantage was/is that there is no incentive for individual owners to reduce fuel consumption, for example by lowering the thermostat, by switching the heating off when they are absent, or by installing double glazed windows.

Recent legislation in Lombardy therefore introduced the requirement for all apartment blocks to introduce thermal billing systems which allow heating system costs to be shared between households based on actual fuel use by single properties. There are a number of ways that this can be achieved, either by placing thermal meters on all the radiators in an apartment, (which when calibrated allow the power output and hence the energy use over a period of time to be determined), or by directly measuring the temperature difference and the flow rate of hot water to and from an apartment.

However the regional building code (DGR della Regione Lombardia IX/2601 del 30/11/2011) also requires that any billing system should also take account of the exposition of the single apartments. This since the heating requirements of any property depend not only on factors which can be modified by the owner (for example thermostat temperature) but also on other factors over which the home owner has no direct control (such as the orientation of the external walls of the apartment).

Also it must be remembered that most existing apartments were purchased before the requirement for Energy Performance Certificates was introduced. So home owners had no chance of choosing the more efficient property within the apartment block. Thus the new legal requirement to introduce thermal billing on existing properties risks placing those home owners with apartments unduly exposed (for example with ceilings facing the unheated attic) at a discrete disadvantage with respect to homes surrounded on all sides by heated apartments.

Unfortunately a significant proportion of thermal billings systems are being installed which only take account of the size and the power of the radiators located in each apartment with which make no reference to the question of thermal dispersion from the apartment. Billing in this way does not conform to building codes and could be contested should some owners feel they are paying more than their fair share of fuel costs.

Aldar designs thermal billing systems according to the DGR della Regione Lombardia IX/2601 del 30/11/2011in line with the UNI 10200 standard.

This fact sheet explains in detail the actions required to develop a thermal billing system in line with statuary requirements.

To obtain a quote, call 327 597 8957 or write to

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