In order To understand the significant savings benefit which is achieved by insulating a building (roof and walls), in houses with thermal insulation and especially in new buildings which are constructed according to the KENAK specifications, less than 3-5 litres of heating oil per square metre per year is required, while older and uninsulated buildings require 25 litres on average. Some buildings even need 60 litres per square metre per year.
External insulation significantly reduces heating (oil and gas) costs in winter and air conditioning (electricity) costs in summer. The main points of heat loss occur in the walls.
The building sector is particularly energy-intensive, accounting for 30% of the country's energy consumption. A large part of the energy consumption is due to the fact that most buildings in our country have zero to no thermal insulation.
In this context, energy saving in buildings can be an important energy source, and efforts of the international community have been focused in this direction.
Referring to the geographical area of Greece, where the increase in the temperature of the urban environment has dramatically altered the energy needs of urban buildings, especially during the summer period, the scope margin for energy savings in buildings through thermal protection of the building envelope is very large.
Thermal insulation of buildings is no longer a luxury, but a prerequisite under Directive 2002/91/EC of the European Parliament and of the Council on the energy performance of buildings.