In autumn and winter, heating expenses make up a major part of the expenses for apartment owners.
There are several ways of reducing these costs. For example, in buildings where a renovated heating system has been equipped with automatic devices, the temperature of the water used for heating can be regulated by a thermostat. By turning down the temperature during night-time, many housing associations can achieve savings up to 25% of the heating expenses.

Energy audits show that rebuilding the heating system has the highest rate of return out of all the renovation investments made by the housing associations. The payback period is about 6 or 7 years and energy savings are about 15-20 per cent. In the case where an old heating system is replaced, the energy savings can be even greater (even as high as 50% of the original figure).

In order to choose the best materials for replacing the heating system one should consult an engineer or another specialist. Even though most of the materials on the market today fulfil the requirements, companies that sell or install the materials will tend to make recommendations based on their own interests.

A heating system consists of three parts:
1. the (manual or automatic) heating station, possibly with a heat pump
2. hot water pipes – a one- or two-pipe system
3. heaters (which are usually the radiators)

Each component can be viewed as an independent element, but the operation of each depends on the others. When one of them is renovated, the parameters for the whole system must be taken into account.