Why insulate the walls

The opaque vertical structures which delimit most buildings bear the greatest responsibility for thermal exchanges between the inside and the outside.

It is estimated that when restructuring, thermally insulating the external walls alone allows achieving energy savings of 20-25% in the case of single-family buildings, and of 30-35% for condos.

In passive buildings and in those with a very low energy consumption (Nearly Zero Energy Buildings) the opaque outside walls are characterised by very low thermal transmittance values, ranging between 0,10 e 0,20 W/mK^2.

 

These values can be obtained through various building methods and by placing the insulating layer:

• inside the cavity
• on the inner side of the walls
• on the outer side of the walls

 

The advantages of external insulation

Insulating externally produces performance, operational and economic advantages:

• applying a continuous layer of insulation eliminates heat bridges
• insulation protects structures from large temperature changes thereby ensuring a longer life
• the structural mass, concentrated inside, allows taking advantage of its thermal inertia: the walls cool down and heat up more slowly
• constructing single-wall buildings with an external insulation is cost effective compared with double masonry wall solutions

When restructuring, insulation from the outside has further advantages:

• the intervention does not reduce the internal dimensions of the housing
• it can be achieved without compromising the fitness of buildings and with the least inconvenience for the inhabitants
• management of the site, outside the buildings, is easier and less invasive
• it improves sound insulation
• the real estate obtains an energy and aesthetic re-qualification upgrade, and the intervention can be organised in order to coincide with facade maintenance works