More than ever, we are aware of the importance of restoring the equilibrium between the preservation of cultural heritage, a comprehensive approach to energy conservation and a healthy living environment.

looking back on 2000 years of insulation

The Romans invented window glass to keep out the cold and let in the light. Until the 1973 oil crisis, windows in residential properties were fitted with single-glazing solutions. After all, these houses and the windows were still standing centuries after their construction, the living environment they provided was healthy and their architecture was worth preserving. Since then, however, new insulating solutions have been applied to windows every ten to 15 years, replacing them almost as quickly with more and thicker insulating solutions without earning back the energy and money invested into them. The problem with all this waste is that we are continuing – in the meantime – to generate CO2 emissions. We have lost sight of the original goal, moving further and further away from a natural and healthy living environment.


Ever since the oil crisis in the 1970s, government and industry have worked to promote the energy label and convince us to purchase increasingly thick and complicated insulation solutions (e.g. double-glazing, high performance glass, Triplex glass, wall insulation, roof insulation, floor insulation, sealing and mechanical or electronic ventilation technologies).
While campaigns have advocated choosing the best insulating glazing and thick insulation solutions as a means of reducing CO2 emissions and complying with energy label standards, they overlook the need to strike a balance between the needs of the original building and our health.

dangers of overinsulation

Overinsulation can result in dampness issues and the growth of mould. Moreover, it has been demonstrated that a qualitatively poor indoor environment can be harmful to the structural aspects of buildings and the health of its users. According to research conducted by the Dutch Ministry of Housing, Spatial Planning and the Environment (VROM), ‘the effects range from feelings of anxiety to serious conditions, including asthma and cancer’. In addition, the structural failure of cultural heritage is occurring more and more frequently due to the excessive use of insulation, and overinsulation is indeed proving uneconomic.

insulation in equilibrium

While Van Ruysdael advocates the use of insulation, it is well aware that this must be done in a natural way and in a manner that is in balance with the existing environment. In order to maintain a healthy indoor environment, the glass needs to be the coldest surface of any building’s structure. Van Ruysdael glass achieves this while ensuring at the same time that more of the heat is retained indoors. Insulation in equilibrium: achieving maximum performance with minimum intervention in respect of cultural preservation and heat retention, health and the environment. 

cultural preservation

One of the biggest challenges we currently face is making existing buildings sustainable, while also preserving them and their beauty. In maintaining the original window, Van Ruysdael provides precisely the right glass features that will allow the value of the typical architectural styles so common in our country to continue to appreciate in value. Moreover, it reinforces the original window design. This is how we maintain the beauty of original windows for the long term.

healthy living environment

A healthy living environment is our aim, not just for the benefit of the political world and the economy, but primarily to benefit ourselves. Van Ruysdael wants to create an improved living environment for the greatest possible number of people by conceiving well‑considered solutions that promote natural ventilation and a healthy indoor environment.


The amount of energy involved in implementing Van Ruysdael’s 'insulation in equilibrium' concept exceeds by many times the energy that has to be invested in existing standard insulation solutions. Insulation in equilibrium entails saving energy and preserving what is good.
Van Ruysdael glass lasts many times longer than standard double glazing. 
Van Ruysdael aims for its products to have the same life span as the buildings/windows and ensures that no unnecessary materials are used in the process. This is how we work together to create a sustainable environment that goes to the very heart of what it means to be sustainable.


The return achieved by the Van Ruysdael 'insulation in equilibrium' concept far exceeds the investment needed. An investment in Van Ruysdael glass and fitting materials is low, particularly with regard to the unrivalled technical and aesthetic performance and long life span of these products. The original architecture is preserved and unique attributes are added, which is why a building will increase in value.

insulation in equilibrium | Van Ruysdael