Energy efficiency at home It's not just a trend; it's a pressing need in a world where saving energy, reducing monthly expenses, and improving interior comfort have become priorities. Thermal insulation, when well-chosen and properly installed, is the key to achieving a home that's warmer in winter, cooler in summer, and much more sustainable. If you've ever wondered how you can improve the well-being of your home while also helping to protect the environment, here is the most relevant and detailed information on insulation materials in modern construction.
Throughout this guide, we'll thoroughly explain the types of materials available, how they work, their advantages and disadvantages, the regulatory aspects to consider, and everything you need to know before choosing, installing, or renewing insulation for your home. We assure you that after reading this article, you'll have a comprehensive view of the current situation and will be able to make informed decisions. You will optimize your investment in comfort, savings and sustainability.
Why is thermal insulation so important in a home?
Thermal insulation plays a fundamental role in the construction and renovation of modern homes. Its main purpose is to reduce heat transfer between the interior and exterior of the home., helping to maintain a constant and pleasant interior temperature, regardless of whether it is freezing cold or stifling hot outside.
Thanks to a good choice of insulating materials, it is achieved reduce heat loss in winter and overheating in summer. This translates into less dependence on heating and cooling systems. In addition, a well-insulated home is not only more comfortable, but also contributes to reducing CO₂ emissions associated with energy production, which has a direct impact on environmental sustainability.
But insulation does not only serve an energy function. Reduces the transmission of outside noise, protects against moisture, prevents the growth of mold, improves the health of residents, and can even increase the market value of the home by improving its energy efficiency rating.
How does a thermal insulation material work?
La The key to an effective insulator lies in its low thermal conductivity, that is, in its ability to slow the passage of heat through it. The lower this value, the better the performance of the material and the greater the energy savings for the home.
To measure the effectiveness of a material, two concepts are used:
- Thermal conductivity (λ): Indicates how easily the material allows heat to pass through. The lower the temperature, the better.
- Thermal resistance (R): Reflects the ability to resist the passage of heat. It increases as the thickness of the material increases, and conductivity decreases.
In practice, proper insulation is achieved by combining the right material, the correct thickness, and professional installation that avoids thermal bridges and faulty joints.
Regulations and rules on thermal insulation in Spain and Europe
The construction sector in Spain is subject to demanding regulations. aimed at promoting energy efficiency and reducing emissions. The European Directive 2010/31/EU and the constant development of the Technical Building Code (CTE) They establish the minimum insulation standards that buildings must meet. The main regulatory frameworks include:
- Regulation of Thermal Installations in Buildings (RITE) – Royal Decree 1027/2007, updated by Royal Decree 178/2021: Regulates the design and maintenance of thermal installations, promoting the use of materials with high energy efficiency and low environmental impact, including natural insulators.
- UNE-EN 13501-1 Standard: Classifies the fire behavior of insulating materials, a particularly critical issue in Spain, where fire safety in homes and buildings is a priority.
- Technical Building Code (CTE): Establishes the minimum insulation requirements by climatic zone, type of building and other construction characteristics.
These regulations require the use of products that are not only thermally efficient, but also sustainable, safe and with low polluting emissionsFurthermore, a home that meets these standards is eligible for aid, subsidies, and market revaluation.
Types of Insulation Materials: A Comprehensive and Updated Guide
There are many insulating technologies and materials on the market, each with specific properties, applications, advantages, and limitations. There is no universal "perfect insulator", but a variety of options that best suit the project characteristics, climate, budget and regulatory requirements.
Below is a detailed review of all the systems most commonly used in new construction and renovation projects:
synthetic insulation
Synthetic materials come mainly from petroleum derivatives and plastics. Their greatest advantage is their thermal efficiency, lightness and moisture resistanceSome of the most common are:
- Expanded polystyrene (EPS): Widely used due to its low cost, easy handling, and good insulation capacity. It is usually available in sheets, panels, or in bulk for injection into air chambers. Suitable for walls, floors, facades and roofs. Lightweight, rot-resistant, and water-resistant, it can be flammable if not added with flame-retardant additives and releases toxic gases when burned.
- Extruded polystyrene (XPS): Similar to EPS but with a closed-cell structure. Waterproof, more resistant to compression, and with lower water absorption. Ideal for roofs, floors and areas susceptible to moisture. Also flammable unless treated with special additives.
- Polyurethane (PUR/PIR): It stands out for its extraordinary insulating capacity (high R-value in a thin layer) and excellent resistance to moisture. Available in rigid panels, sandwich panels, sprayed or injected foam, and even custom-shaped pieces. It is used in facades, floors, ceilings, and chambers. You can be flammable if not treated. and releases toxic gases when burning, although new variants improve fire safety.
- Reflective insulators: Formed by layers of polyethylene bubbles and aluminum sheets, They work mainly by reflecting radiation. Recommended more in mild or warm climates.
Its advantages include durability, versatility, and ease of assembly. However, Its fossil origin means a greater environmental footprint than other options., so if you are looking for maximum sustainability you should consider alternative materials.
Mineral wools and inorganic fibers
Mineral wools are probably the most widely used group for both thermal and acoustic insulation in homes. They are manufactured from volcanic rocks (rock wool), sand (glass wool) or recycled minerals, producing filaments that can be arranged in mats, panels, batts, or sandwich panels. Its strengths:
- Rock woolExcellent fire resistance (it's non-combustible, class A1), very thermally efficient, and has excellent acoustic insulation. It's used in walls, roofs, raised floors, and facades, both in new construction and renovations. Resistant to moisture and mold.
- Glass woolLighter, with better sound insulation than rock wool, and highly resistant to moisture. Also fireproof. It's equally used in all types of enclosures.
- Fiberglass: Widely used in roll form, blankets, or blown into air chambers, due to its low conductivity and ease of installation. It is an inexpensive and versatile material, although it can cause irritation during handling and requires protective equipment.
Mineral wools and inorganic fibers Not only do they insulate from heat and cold, but they also dampen noise, are recyclable and do not generate toxic gases.. In addition, they do not decompose or lose properties over time when installed correctly.
Natural and ecological insulators
The rise of sustainable construction has boosted the use of 100% natural, recyclable, and low-carbon insulation. They're perfect for those seeking environmentally friendly materials and a healthier interior:
- Cork: Perfect thermal and acoustic insulation, moisture-resistant, and virtually everlasting. Available in panels, chips, or granules. Fully recyclable and renewable.
- CelluloseMade from recycled paper treated with boron salts to prevent pests and fire. It is blown into chambers or used as a blanket, offering high insulation capacity and good moisture control.
- Linen and hemp: Low environmental impact, versatile, breathable and biodegradable plant fibers.
- Sheep wool: Ideal for humid climates, it improves its insulating capacity when moistened and is completely natural and renewable.
- Clay, perlite and vermiculite: Expandable minerals that provide fire-resistant capacity, suitable for filling and reinforcement in walls and floors.
Eco-friendly insulation combines efficiency, breathability, and environmental friendliness, although it can be more expensive initially than synthetic insulation.
Sandwich panels and composite materials
The sandwich panels They consist of two outer layers of steel, wood, or plaster enclosing an insulating core of polyurethane, mineral wool, or other materials. They are common in renovations, facades, industrial roofs, and modular homes.
They grant Great structural rigidity, quick installation and improved thermal and acoustic performance, although they depend on the insulating material of their core to achieve greater performance.
Reflective insulation and innovative solutions
In recent years, advanced materials have emerged that reinterpret traditional insulation:
- AirgelWith its extremely low density and unparalleled insulating capacity, it's used in the aerospace industry and is gradually being used in construction. For now, its high price limits its residential use.
- Reflective aluminum insulatorsThey combine several layers to maximize resistance to radiant heat. They are common in warm climates or as a complement to other systems.
- Thermally insulating acrylic paints: Liquid solutions to improve the thermal performance of walls and ceilings without any additional work, although their effectiveness is more limited and they serve as a complement.
Main applications of insulating materials in housing
Insulation can be installed in virtually all elements of the home's envelope. The areas where the greatest gains in comfort and energy savings are achieved are:
- Facades (exterior, interior or in air chambers)
- Roofs and coverings
- Floors and floors
- Windows and openings (although here the glazing and carpentry are more important, supported by sealants and blinds)
Although most heat gain/loss occurs through the façade and roof, other aspects, such as thermal bridges or joints between construction elements, should not be overlooked.
Key attributes for choosing the best insulation material
Deciding which insulation is best for your home should be based on a combination of factors. It's not just about choosing the cheapest or the one with the highest R-value, but rather about considering all relevant elements. Key factors include:
- Climate zone and locationIn cold climates, materials with high thermal resistance are required, while in hot or humid climates, materials that block radiation or are waterproof are more important.
- Type of constructionOlder houses, apartments, penthouses, or single-family homes all have different insulation needs and installation methods.
- Budget availableInitial price, long-term savings, and durability are key. Some materials may be more expensive but last many years or require less maintenance.
- Space available to install: Sometimes it is interesting to use a material with high insulating value and a thin layer so as not to lose useful space.
- Environmental impact: Recycled, recyclable, or natural options for those who prioritize health and sustainability.
- Easy installation: If you're going to hire professionals or plan to do it yourself, there are systems that are simpler and faster than others.
- Fire resistance: Essential issue for home security, considering the European classification and Spanish regulations.
- Resistance to moisture and mold: Essential in basements, attics or homes in humid areas.
- Acoustic propertiesNot all insulators provide noise insulation; mineral wool, for example, is also excellent in this area.
In addition, it is important to take into account the local building regulations and standards, which may impose minimums or recommend certain products for each area and building type.
Advantages of thermal insulation: much more than energy savings
Investing in a quality insulation system will allow you to enjoy benefits that go far beyond simple savings on the energy bill. The reduction of heat transmission generates a greater interior comfort, improve the Energy Efficiency and promotes a healthier and more sustainable life.
- Thermal comfort: Indoor temperatures will be much more stable and pleasant throughout the year.
- Economic savingsThanks to the reduction in energy consumption, the investment pays for itself in just a few years.
- Sustainability and emissions reductionLower energy consumption means less CO₂ in the atmosphere and greater environmental commitment.
- Increase in the value of housingA well-insulated property obtains better energy ratings and is more attractive on the market.
- Zero maintenance:Good insulation, properly installed, requires virtually no maintenance for decades.
- Health and well-being: Goodbye to damp, drafts, mold, and annoying outside noises.
Behavior of insulating materials against fire and humidity
Another essential criterion when selecting the insulating material is its fire behavior and ability to resist moisture. Reaction to fire is classified, according to UNE-EN 13501-1, as follows:
- Class A1 and A2: Non-combustible (rock wool, glass wool, laminated plaster)
- Class B, C, D, E and F: Descending fire behavior, with F being the lowest resistance
Rock wool and mineral wool stand out especially, since They can withstand high temperatures without spreading fire or releasing toxic gases.Plastic materials such as EPS, XPS, and polyurethane can be flammable and release dense smoke unless specially treated. Cellulose treated with boron salts also improves its fire resistance.
Regarding humidity, it is advisable to use impermeable and non-absorbent materials in basements, flat roofs, or wet areas. Extruded polystyrene (XPS) and polyurethane are especially suitable for humid environmentsNatural products tend to be more breathable, which helps regulate moisture and prevent mold growth.
Installation Options and Methods: How are Different Insulations Installed?
La correct installation The quality of insulation materials is just as important as the choice of the material itself. Poor installation, with thermal bridges or inadequate sealing of joints, can significantly reduce the effectiveness and lifespan of the insulation. The most common installation methods include:
- Rigid panels and sheets: They are placed on facades, floors and roofs. Easy to install and very versatile.
- Flexible blankets and rollsIdeal for interior walls, ceilings, and floors. They can be adapted to irregular shapes.
- Blown-in fluff: It consists of blowing loose material (wool, cellulose, EPS beads) into air chambers or false ceilings.
- Sprayed foam: Polyurethane or cellulose can be applied by spraying, creating a continuous, seamless layer.
- SATE Systems (External Thermal Insulation System): One of the most effective solutions for façade rehabilitation, it combines panels (usually EPS) adhered and coated with mortar.
- Cladding with laminated plaster: Plasterboard panels installed indoors with insulating panels, eliminating thermal bridges and improving habitability.
- Reflective insulators: They are installed in ceilings, false ceilings and roofs, especially in areas exposed to direct solar radiation.
Remember that a Professional installation and a preliminary study of air chambers, thermal bridges and orientation They are vital to maximise the performance of the insulation and ensure a long-lasting result.
Maintenance and updating of thermal insulation
Maintaining quality insulation requires minimal care, although it is advisable to perform Periodics inspections to detect dampness, deterioration, or material shifting due to subsequent work or leaks. In older or renovated homes, Upgrading insulation can significantly improve comfort and energy efficiencyTechnology is constantly evolving, so it's important to stay informed about new solutions available.
Combination of materials for an optimal result
A growing trend is the combination of different insulators to take advantage of their benefitsFor example, using rock wool for acoustic and thermal insulation in walls, along with XPS panels in floors, or using synthetic materials outdoors and natural materials indoors to regulate humidity and improve air quality. It is also advisable to include vapor barriers in sensitive areas to prevent condensation and prolong the life of the system.
Special applications: insulation in unique spaces
In addition to common areas, insulation is essential in spaces such as garages, basements, attics, pitched roofs and cold storage rooms. Selecting materials that can withstand moisture, temperature changes, and fire exposure is crucial and must be tailored to the specific needs of each space.
In garages and basements, waterproof and compression-resistant insulation is recommended, while in attics and roofs, lightweight materials with high insulation capacity and good radiant heat resistance are preferred.
Innovations and sustainability: the future of insulation
The insulation materials sector is evolving rapidly, driven by product demand. more efficient, ecological and with less environmental impactCurrently, the following stand out:
- Carbon-neutral polyurethane foams, much more respectful of the environment.
- Recycled and recyclable materials, such as cellulose, flax, wood fiber and cutting.
- Combined systems with reflective and natural barriers, which maximize performance in all scenarios.
- Smart panels and paintings, capable of adapting their behavior according to ambient temperature and humidity.
Moreover, the digitalization and home automation They allow you to monitor and optimize your home's energy use, complementing the performance of insulation and promoting more responsible and efficient consumption.
Common mistakes and tips before insulating your home
Before proceeding with the installation or renovation of insulation, keep these tips in mind to avoid common mistakes and ensure an effective result:
- Do not underestimate the prior study of the walls and air chambersIt is essential to identify thermal bridges and plan tasks correctly.
- Correct any thermal bridges before installing insulation to prevent heat loss.
- Consult with professionals specialized in insulationEvery home has its own unique characteristics that require customized solutions.
- Don't just look to reduce costs on materials: Poor execution can negate the benefits of the system.
- Check the compatibility of the insulation material with local regulations.
Frequently asked questions about thermal insulation
How much does good insulation really save?
Professional insulation can reduce energy consumption by up to 30%. of a home. Investments in insulation for facades and roofs are amortized in less than five years in most cases.
What material is best for areas with high humidity?
For humid environments, it is advisable to opt for XPS, sprayed polyurethane or sandwich panels with a waterproof core. Indoors, natural materials help regulate humidity and prevent mold.
How is the effectiveness of an insulator measured?
Mainly, because of its R-value y thermal conductivity (λ)A high R-value and a low λ indicate better insulating capacity, complemented by thickness and proper installation.
Can insulation be installed in an existing home?
Yes, there are various methods, from air injection into chambers to interior cladding or ETICS systems on façades. A prior study is essential to adapt the project to existing structures.
The starting point for an efficient and healthy home
Updating or installing good insulation in your home is essential for achieving a more comfortable, economical, and sustainable home. The wide range of existing solutions allows the investment to be adapted to each need and climatic environment.Consulting with professionals, comparing features, and taking into account local regulations will facilitate a wise and lasting choice.
Investing in insulation not only provides protection against the cold and heat, but also improves quality of life, helps reduce costs, and contributes to the fight against climate change. With the information provided here, you have the tools to take the step toward a more efficient and healthy home.
