What is blown thermal insulation?

Blown thermal insulation is the cheapest and most effective solution for saving energy. Approximately 30-35% of heat loss or cold input in a house is produced by the walls, but thanks to this technique your home will gain in efficiency and comfort forever, since it does not need maintenance.

How is it installed?

Without building works

Blown thermal insulation is a very simple intervention. It can be carried out through the outside of the façade, or on the inside (without the need for scaffolding). It does not require planning permission.

Air chamber

This is the gap that separates the inside brick wall from the outside wall. If your house was built between 1960 and 2006, it is most likely to have a cavity.

Speed

A flat can be insulated in one day. The insulating material is injected through small holes in the wall, filling the cavity. It provides homogeneous insulation while preventing draughts - and it also insulates acoustically!

Advantages of thermal insulation with Iberdrola

Heat and cold escape from your home without you realising it, take the plunge and turn your house into an efficient home.

Ahorro

Savings on your bill

Consume less energy and reduce your gas or electricity bill by up to 30%.

Gestiona Energia

Peace of mind

Installation without building works in one day. No maintenance, no associated costs.

Ahorro

Comfort

More comfort at home, both in winter and summer. Reduces noise from outside.

Luz Verde

Easy payments

You can finance the installation of insulation according to your needs.

Thermal insulation calculator

1/4 Type of home

Next: Size of home

1. Select home type

Flat

Terraced house

Semi-detached house

Detached house

2/4 Size of home

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2. Select the size of your home

Choose the area that is closest to its actual size.

2/4 Size of home

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2. Select the size of your home

Choose home type that best suits the characteristics of your home.

2/4 Size of home

Siguiente: Wall cavity size and finishes:

2. Select the size of your home

Choose home type that best suits the characteristics of your home.

2/4 Size of home

Siguiente: Wall cavity size and finishes:

2. Select the size of your home

Choose home type that best suits the characteristics of your home.

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

3/4 Wall cavity size and finishes:

Next: Summary and personal details

3. Does your house have an air chamber?

4/4 Summary and personal details

4. Your recommended thermal insulation

Ask for a quote and start saving

One of our qualified technicians will visit your home to provide you with a custom quote

Type of home: terraced

Surface area: Up to m2

cm air chamber cm

€(1)

Request quote

(1) The reduced VAT rate of 10% applies to natural persons in private homes (not for professional or business purposes) and residents' associations

4/4 Summary and personal details

4. We have other solutions for you

Blown-in thermal insulation requires an air gap, but thanks to our Smart solutions you can also achieve an efficient home and save on your bill. Find out which one is best for you:

Smart Home

Smart Home

Control your home from your mobile, control heating, turn lights on and off.

Find out more
Smart-clima

Smart Clima

Turn on and off and control temperature in your home, wherever you are. It?s much easier now.

Find out more

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Calculate again

€/month incl. VAT in 12 interest-free payments

Estimated price for

m linear meters of exterior façade insultarion, height of 2.5m and 20% of wall cavities. Volume of wall cavity to be filled approximately

m3.Estimated reduction of heating and cooling consumption of 15% for homes constructed before 1980, and of 10% for homes constructed between 1980 y 2006

m3.Estimated reduction of heating and cooling consumption of 20% for homes constructed before 1980, and of 15% for homes constructed between 1980 y 2006

Do you want to benefit from Energy Savings Certificates?

Join the change, at Iberdrola we help you to be more efficient with your energy and maximise your savings.

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Any questions?

Here are some of the most frequently asked questions

Thermal insulation
Blown
thermal insulation
Price and savings
Customised

Aislamiento térmico

Thermal insulation consists of controlling heat transmission from a building, insulating it from the outside temperature or from other parts of the building to minimise heat loss in winter and gains in the summertime.
Thermal insulation is the main, cheapest and most effective energy-saving measure. What's more, most thermal insulation provides effective sound insulation, keeping bothersome noise out of the building.

Because 40 % of the energy consumed by Spanish households is used for heating and cooling.
There are numerous simple ways of insulating the home which can significantly reduce the amount of heat wasted and keeping gas and electricity bills lower (for heating and air conditioning).
Any renovations and modernisation carried out on the home are a superb occasion for analysing energy efficiency and insulation: you'll gain in comfort, lower your bills and emissions and add to the value of your home.
Spain has set itself an objective within the National Integrated Energy and Climate Plan (PNIEC) to upgrade 1.2 million homes by 2030.

The roof, walls, windows, doors and floors are the main areas where warm air escapes and cold air gets in.
Although there is no "one-size-fits-all" solution, generally speaking, houses lose warmth as follows:
  • from 30 % to 35 % through walls and thermal bridges
  • Around 25 % through the roof and terraces
  • up to 25 % through doors, windows, seals, and cracks
  • Between 7 % and 15 % through the floor, depending the type of home
That's why insulating your walls and roof is the quickest and most efficient way of reducing energy consumption in the home.zonas conviene aislar

There are three main methods for improving thermal insulation of walls and roofs:
  • From the outside, it's the most efficient way to reduce energy demand, with the External Thermal Insulation Composite System (ETICS) or ventilated façade. The drawback is that the project must tackle the entire building, it can take several weeks, and it is the most expensive solution.
  • Insulation can be installed on the inside (lining), with multiple solutions existing on the market. The drawback is that it reduces the amount of living space in the home and does not deal with thermal bridges.
  • In the middle: a very quick, economical and effective technique is insulation injecting insulating material into the air chambers of walls and roofs, provided that the dwelling has double partition walls (double-leaf façades, façades with air chambers) or a false ceiling. The drawback is that it can only be used if there is an air chamber. Like the facing shell method, it does not resolve the thermal bridge issue.
You can also improve openings, improving insulation of exterior doors and windows. There are many ways to improve insulation with windows, installing double glazing in metal-framed windows, with or without thermal bridge breaking, or triple glazed windows with low emissions treatments and PVC frames with excellent thermal efficiency. Depending on the climate, the orientation of the gap and your budget, you will always find a solution that will improve the energy efficiency of the home.

The first noticeable change in the home is comfort. It will stay warmer for longer in winter and cooler in summer. In winter, I will notice that the walls are not as cold as they used to be before I installed the insulation and that my home will feel far more comfortable. I will notice less difference in the temperatures between different parts of the rooms.
The heating/cooling system will start up less frequently, and I will notice fewer temperature variations. This will mean lower heating/cooling bills.
Improved insulation helps to prevent draughts, moisture and mould, improving living conditions and health.

Blown thermal insulation

If the home has double partition walls (double leaf façades, façades with air cavity) or false ceilings, insulation by blowing insulating material into these cavities is a quick, economical and effective technique.
The insulating material is blown into the air cavity, filling the entire cavity and providing homogeneous insulation while stopping draughts. And it also provides sound insulation!

The solution has been used for more than 30 years and is used widely in countries with a continental climate. In the United Kingdom, more than 10 million homes have been fitted with blown cavity wall insulation. Different materials are used depending on the type of chamber and home. We can advise you on which material is most suitable for your home.

Holes are made in the brick or in the partition wall and the insulation material is blown through. The holes are then carefully sealed so that there is no sign of the operation. Holes are made all over the façade so that the insulation covers the entire wall. The insulation completely fills the air gap, leaving a layer of insulation that not only insulates but also prevents outside air from coming through the air gap.

It can be done from either the outside or the inside. In the case of flats, it is done through the inside to avoid using scaffolding and supporting structures.

If you want to install blown cavity wall insulation in your home, you need to find out if there is an air cavity in your walls.
If your home was built after 1960 and before 2006, it most likely has air cavities. If it was built after 1979, it probably has some insulation, although it is probably insufficient.
If the wall sounds hollow when you bang on it, or if when you go close to the socket (without touching it) you notice air currents, then you have air cavities.
In any case, an Iberdrola partner can come to your home to see if there is an air cavity and measure its thickness to provide you with an estimate for blown cavity wall insulation.

No. It's a simple process. It takes just hours or a day to insulate a flat. In the case of a detached house, it can take one or two days to insulate.
The operation can be carried out from the inside or the outside, provided that there is a common electricity supply for the blower. In the case of tiled rooms, it is preferable to insulate from the outside to avoid perforating the tiles.
There is no requirement for a building permit and additional equipment is only needed in the case of high buildings. In such cases, if the building residents' association agrees, the cost of additional measures is offset with the economy of scale of making the improvement jointly.

The benefits of thermal insulation continue throughout the life of the building. It needs no maintenance and there are therefore no additional costs.
Different materials are used in blown cavity wall insulation, but they all have properties or treatments that mean they require no maintenance. Thermal insulation will reduce the demand for energy in the home, which will put a smile on your face when you see your fuel bills are lower, year after year. The planet will thank you, too. What's more, it will improve your quality of life and provide sound insulation.

Iberdrola recommends glass mineral wool as the best choice for insulation, due to its superior thermal properties and durability compared to other materials.
Glass mineral
wool		 Polyurethane Rock wool Cellulose EPS
Thermal properties
Excellent
Excellent (Conductivity 0,034w/m2k)
 Excellent
Excellent (Conductivity 0,034w/m2k)
 Good
Good (Conductivity 0,038w/m2k)
 Good
Good (Conductivity 0,040w/m2k)
 Excellent
Excellent (Conductivity 0,035w/m2k)
Fire resistance
Excellent
Flame-resistant (Euroclass A1)
 Low
Inflammable (Euroclass E)
 Excellent
Flame-resistant (Euroclass A1)
 Medium
Fire resistant (Euroclass B2)
 Medium
Fire resistant (Euroclass B2)
Water absorption
Excellent
Waster resistant
 Excellent
Waster resistant
 Excellent
Waster resistant
 Deficient
Does not resist water
 Excellent
Waster resistant
Durability
Excellent
Long-lasting (Settlement S1)
 Medium
Losses quality
 Excellent
Long-lasting (Settlement S1)
 Medium
Losses quality(Settlement S3)
 Excellent
Long-lasting (Settlement S1)
Drilling
Excellent
Nozzle (From 16)
 Excellent
Nozzle (From 16)
 Low
Nozzle (Usually 38)
 Low
Nozzle (Usually 38)
 Excellent
Nozzle (From 16)
Sound insulation
Bien
Good isolation
 Deficient
Does not isolate
 Bien
Good isolation
 Bien
Good isolation
 Deficient
Does not isolate
Thermal properties
Glass mineral wool Excellent
Excellent (Conductivity 0,034w/m2k)
Polyurethane Excellent
Excellent (Conductivity 0,034w/m2k)
Rock wool Bien
Good (Conductivity 0,038w/m2k)
Cellulose Bien
Good (Conductivity 0,040w/m2k)
EPS Excellent
Excellent (Conductivity 0,035w/m2k)
Fire resistance
Glass mineral wool Excellent
Flame-resistant (Euroclass A1)
Polyurethane Low
Inflammable (Euroclass E)
Rock wool Excellent
Flame-resistant (Euroclass A1)
Cellulose Medium
Fire resistant (Euroclass B2)
EPS Medium
Fire resistant (Euroclass B2)
Water absorption
Glass mineral wool Excellent
Waster resistant
Polyurethane Excellent
Waster resistant
Rock wool Excellent
Waster resistant
Cellulose Excellent
Waster resistant
EPS Excellent
Waster resistant
Durability
Glass mineral wool Excellent
Long-lasting (Settlement S1)
Polyurethane Medium
Losses quality
Rock wool Excellent
Long-lasting (Settlement S1)
Cellulose Medium
Losses quality(Settlement S3)
EPS Excellent
Long-lasting (Settlement S1)
Drilling
Glass mineral wool Excellent
Nozzle (From 16)
Polyurethane Excellent
Nozzle (From 16)
Rock wool Low
Nozzle (Usually 38)
Cellulose Low
Nozzle (Usually 38)
EPS Excellent
Nozzle (From 16)
Sound insulation
Glass mineral wool Bien
Good isolation
Polyurethane Deficient
Does not isolate
Rock wool Bien
Good isolation
Cellulose Bien
Good isolation
EPS Deficient
Does not isolate
Excellent Excellent Good Good Medium Medium Low Low Deficient Deficient

Price and savings

No. It is the most economical option for reducing the need for heat and cold in a home.
It costs between around €800 and €1500 to insulate a flat. A detached home from €1200 to €2,500 or even more in the case of a large property.
The thicker the chamber, the more insulating material is needed to fill it and the greater your savings on heating and air conditioning.
It's the ideal solution if you have air chambers and gives you the best return on each euro invested in insulation.

Each home is unique. For this reason, a home visit is necessary to inspect the cavity to check the condition, feasibility of the installation and potential for improvement.
All our estimates are made to measure and after a technician's visit, since it is impossible to assess from a distance and even more so taking into account the enormous variability inherent in architecture.
The surface area of the house to be insulated tells me how “big” the shelter to be placed will be, and the size of the cavity how “thick” that shelter will be.

To ease the initial outlay, Iberdrola has agreements with lenders that will allow you to finance it. That means you can pay for your installation while you save on your bills

The amount will depend on the size of your home, the type of heating and the thickness of the cavity. In the case of a home with a gas boiler with an annual consumption of €550, saving 20% of the gas used for heating will reduce the annual bill by around €90 and prevent the emission of 240 kg of Co2 every year. If you have an oil-fired or LNG boiler, the emissions avoided will be higher.
The more you spend on heating your home, the bigger the potential savings and reduction of emissions.
If you also decide to upgrade your heating system, you can choose something less powerful, which will be kinder to the environment and make more savings.

Customised

If you have a false ceiling it can almost always be insulated. If you have air conditioning through ducts with the return without ducting, it should not be insulated. In all other cases, yes.
The larger the space above the false ceiling, the greater potential for gains there will be. We will also have to use more material to fill it, but the additional improvement will be worth the increased cost.

If the space is very large, more than 20cm, it may not be filled completely since the improvement will already be very significant without needing to fill it completely.
If the false ceiling is inclined (attic areas) it is necessary to fill it completely regardless of the space since it is the only way to guarantee that the placement of the material is correct.

These are one of the main points where heat escapes in winter and where heat enters in summer. Our technicians will advise you during the visit, but in almost all cases it should be the first point to improve.
If we have given you a quote for the façade and roof and you are not sure to what extent you wish to contract, the technician will advise you, but the general recommendation will be that we start the insulation with the roof (false ceiling or roof as the case may be).
The house may not start with the roof, but at Aislamiento Smart we do start improving efficiency from the top!

No. The glass mineral wool provides an acoustic improvement, but against airborne noises (voices in the street, cars), not against noises that are transmitted through the structure.

Usually not. The most common construction methods do not allow this. Only in exceptional cases, when we have documentation and know that it is feasible, do we isolate the party walls.

No. You can request a quote and then decide whether one, two, three, eight or all of them take up the offer. The decision will be individual and depending on the number contracted, the efficiency gain in the installation process is transferred in the form of a better price to the customers.

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