When we are about to renovate a house we immediately think about energy efficiency and the resulting savings in bills. Renovate home and home systems is an important investment that can on the first brake for the high cost of estimates, but we must think about the savings in the bill that every year we will have to understand what is the real return on investment, also we must not neglect the aspect of revaluation of the property.

Transforming a house from class G to class A, or even just B, also after the renovation your property will enjoy a real estate revaluation and will also increase the rental value, if you want to make it profitable.

But what are the solutions to improve energy efficiency in the home?
There are two main roads: the purely construction and the plant engineering one. Obviously, acting on all aspects in an integrated way allows to reach a house with high energy efficiency, but sometimes we have to make choices dictated by the budget or just postpone some interventions for a few years.

The building interventions to increase energy performance are those that work on the envelope of the house, so in particular:

Coat or blowing the walls

For the insulation of the outer walls, we can say here that the coat has a significantly higher cost than blowing, but what is blowing? There is a category of houses, typically those with exposed brick built between the 60s and 70s, built with the technique of the internal cavity. This is because in that period of construction it was thought that a wall with still air trapped inside the walls would help to improve living comfort, actually today we know that it is a thermal sieve!

But the cavity construction technique helps us today in the right choice to make to insulate the walls of the house. For all houses built without a cavity we will have to act by putting the coat, which we certainly consider the solution of choice and the first thing to do for the efficiency of the house; for houses with a cavity, however, we can choose to insufflate, or “blow” into the cavity of the insulating material that will create a sort of inner coat.

Roof insulation

However, the insulation of vertical walls should be completed with roof insulation, first of all because if you focus only on vertical walls, you will then have a thermal imbalance in the attic rooms. In addition, it is convenient to carry out all the work together because for the coat or blowing work the scaffolding will already be present.

The costs for insulating the roof of the house vary depending on the intervention and the type of roof. If the roof is made of wood and the structure is in good condition it can be maintained, otherwise it will have to be completely rebuilt.

There is a wide range of types of insulating, ventilated, micro-ventilated, non-ventilated roof package; here Wood ventilation casing and here text ventilated vs non-ventilated roof you will find a good link to the topic.

We suggest the ventilated package because in this case a ventilating air chamber is created that allows the air to pass through and not to cool or overheat the underlying structure depending on the season.

Different the case in which the roof structure is made of concrete: you will keep the structure and you will not need special adjustments, so we consider only the cost of roof insulation. In addition, for all solutions we will still have to consider the costs of sheet metal, which are too variable depending on the specific case.

Replacement of glass and fixtures

The windows and doors are the most vulnerable part of the envelope of our house, from the windows and doors most of the heat energy stored in the house comes out and, conversely, they let the cold or heat pass from the outside depending on the season. Therefore, the replacement of windows and doors cannot be ignored when we approach the energy requalification of our property.

When replacing our windows, we will have to consider the thermal inertia of the two main components, that of the windows and doors and that of the glass which, when added together, will give the total thermal inertia of the window components.

The choice of the type of windows and doors to be purchased can be challenging, because there is a wide variety of types of windows and doors, cost ranges and various pros and cons. We have wooden frames, PVC frames, aluminium frames, or hybrid systems (such as wood-aluminium or PVC-aluminium frames) and for each of these types there are various performance categories that have a great impact on the quality/price ratio.

Let’s not forget that a new window and door with high performance is watertight, this will mean that there will be a strong reduction of both thermal and noise, on the other hand there will have to be a controlled mechanical ventilation system that prevents the formation of mold and ventilates the rooms correctly.

It is clear from the proposals identified above that the solution to be adopted is extremely subjective, may depend on the budget, but also on aesthetic issues and the value we want to give our property.