24/02/2022

Sika solutions enable heat losses in buildings to be greatly deminished. As an integrated supplier of construction chemicals, the company offers sustainable solutions for roofing systems, facades, floor coatings, interior finishing, sealing of doors and windows, or waterproofing of basements. With Sika’s light-reflective roofing systems alone, energy consumption can be reduced by up to 15%. In addition, green roofs by Sika can provide a valuable habitat for plants, insects, and birds, serve as a place of water storage for the controlled release of water in the event of heavy rainfall, and reduce the so-called “heat-island effect”. In all phases of the building life cycle – during construction, operation, and refurbishment – Sika products help to reduce the carbon footprint.

Eric Lempereur
"With our comprehensive and sustainable approach, Sika is perfectly positioned to act as an enabler for the shift towards more sustainable building envelopes." Eric Lempereur, Head of Corporate Target Market Building Finishing
Eric Lempereur, the demand for energy-efficient building envelopes is increasing. How important is the building envelope for the sustainability of a building?

The basic function of a building envelope is to protect the building from the climatic elements and to ensure the durability of the building structure. In addition to this, the building envelope also, in part, determines the energy consumption of a building. In general, about 25% of the heat loss of a building is considered to stem from the roof, 35% from the walls, 25% from the doors and the windows, and the rest from the ground and other elements. This shows that protecting the facade and the roof is very important in terms of improving the energy efficiency of a building. In Europe, it is estimated that more than 75% of today’s building stock is not sufficiently energy efficient. In order to achieve the climate and energy targets set by the EU, more than 35 million houses  will need to revamp their energy consumption profiles.

Heat Loss of a Building

25%

of the heat loss of a building is considered to stem from the roof.

35%

heat loss of a building is coming from the walls.

25%

of the heat loss is from doors and windows.

What does it take for a building envelope to be energy-efficient?

The envelope needs to thermally insulate the building and reduce the heat transfer between the inside and the outside. At the same time, there are other technical and functional requirements: the walls need to breathe for a healthy indoor living environment and at the same time provide a weatherproof shell. This means that the envelope needs to be considered in its entirety. The connections between the different components of the envelope, such as the windows, doors, roof, and facade, are also important as air draft is a key factor for energy savings. They all need to be able to work together as a functional system.


Sika is driving this field forward and offering system solutions. You yourself are an expert on the facade systems. What do these solutions look like?

When it comes to facades, Sika has been developing systems that are referred to as EIFS or ETICS. These acronyms refer to external wall insulation systems that assemble insulation boards with basecoats, adhesives, and decorative and protective finish renders. It is a multilayered approach that connects the functional requirements, such as the insulation and breathability, with the finish and look of the facade. Sika can offer a wide range of solutions for newly constructed buildings and for building renovation, including systems based on bio-sourced material with insulation properties or colored and textured decorative renders.

Facade built with Sika envelope system
Facade built with Sika envelope system
How does Sika ensure sustainable and efficient results in other parts of the building envelope?

Sika of course also offers solutions for the other components of the building envelope, such as sealing and protection materials around the windows and doors with water and air-tight barriers membranes or foams. Sika is also a roofing specialist with a broad offering of sustainable solutions including systems for green or light-reflective roofs. With our comprehensive and sustainable approach, Sika is perfectly positioned to act as an enabler for the shift towards more sustainable building envelopes. 


The greening of roofs and facades is one trend in building envelopes. What other trends and developments are happening in this area?

There is a trend towards zero-emission houses, also called passive houses. There is a general trend to develop new systems that are based on bio-sourced materials, and that can be used for the building envelopes. For example, we developed facade insulation systems with boards or mortars that can incorporate hemp or wood fibers. 

How are building owners and architects dealing with energy-efficient building envelopes? How great is the awareness of this topic?

Awareness has been growing extensively and is already very high among construction stakeholders. There are a high number of certificates, labels, and standards that reflect this when it comes to the construction of new buildings. The challenge is greater in the renovation sector. There is a huge amount of building stock to renovate, especially in “old Europe”. We will continue to focus on developing tailored solutions for renovation and this so-called deep retrofitting of the existing building stock.

What will the energy-efficient building envelope of the future look like? Which direction is the development taking?

The building envelope must be considered in its entirety. It doesn’t just have to reduce energy consumption; sustainability is also about ensuring durability and providing long-lasting solutions for your roof or facade. We are developing finish renders that protect the building from factors like dirt, air pollution, algae, or fungi and that are especially durable. And we are also working on reducing the environmental footprint of the materials used in our mortars formulations by integrating Supplementary Cementitious Materials with a lower CO2 footprint and recycled components. It is a complex and multidimensional topic and Sika is at the forefront of this technological development. The higher the complexity  – the more opportunities we see.