The real value of slim insulation

In an urban environment, space is limited. Architects, developers and investors are constantly looking for ways to increase property returns. Insulating the building envelope plays a crucial role in reducing energy needs, but it can also contribute significantly to increasing financial returns, according to recent research by Kingspan Insulation.

This is not the first time Kingspan Insulation has commissioned research into the true value of lean insulation. "In 2017, research firm Develop Inc. investigated for us whether the higher initial construction costs when applying our Kooltherm K108 Cavity board, as an alternative to glass wool insulation, were recouped through the higher resale value (extra m2 GO x GLA price)," said Dennis van Lit, Specification Manager at Kingspan Insulation and responsible for the business development team in the Netherlands. "In 2018, that study was repeated with a focus on the private rental sector. Both studies showed that the extra investment on construction costs was more than recouped through higher sales value or higher rental income." 

Renewed research: costs versus revenues

The crux of the Kooltherm K108 Cavity Board lies in its reduced thickness. If we assume fixed external dimensions, then with our cavity board a slimmer cavity construction is sufficient," explains Van Lit. "With a lambda value of 0.018 W/m.K, the Kooltherm K108 Cavity Board is the thermally best performing board in the rigid foam insulation board market. Compared to a glass wool insulation board that has a lambda value of 0.032 W/m.K, the application of the Kooltherm K108 results in a slimmer cavity construction for the same external dimensions. This results in more usable area, which in turn represents higher commercial value." Both construction costs and sales and rental income have increased in recent years. Reason for Kingspan Insulation to commission the study again and draw new conclusions from it.

More interior space

The reference for the study of the true value of slim insulation is an apartment complex with thirty apartments, spread over six floors (five storeys) where the values currently in force according to the Building Code were used, i.e. for the facade an Rc value of 4.5. Van Lit: "The extra square meters of user area realized (as a result of the slimmer cavity construction) by using the Kooltherm K108 Cavity Board instead of glass wool insulation is approximately 37 m2. Applying our rigid foam insulation board results in higher construction costs, both directly and indirectly. Directly, because Kooltherm is simply more expensive than glass wool insulation. Indirectly, because the gain from the additional square meters of occupant area translates into higher interior finishing costs. After all, there are more interior walls, more ceilings and floors to finish. On balance, the difference in additional building costs between using Kooltherm versus glass wool in this reference project is about 15,000 euros. The question then is what does that 37 m2 of additional interior space and thus as additional income yield? What is the Return on Investment anno 2020?"

Absolute lower limit

"We only talk about the commercial value now, but the results of the research are also very important in terms of energy. The Kooltherm 108 Cavity Board is a super slim board that achieves very high thermal performance. This is important not only for now, but also for the future. The values in the study apply according to the Building Regulations, so for the facade an Rc value of 4.5. With the entry of BENG, the value will be slightly increased. But we consider that to be the lower limit," Van Lit said. "We always advise doing more than the minimum necessary to further reduce the energy requirement and also to guarantee the indoor climate and comfort. You will further see that those BENG standards are going to be tightened up in the near future and the limit values will be further reduced. If you then continue to work with traditional materials, those insulation packages will become thicker and less lucrative. With this material you can really build future-proof."

Planet Passionate

"Kingspan has already been working on a Net Zero Energy Program since 2011 to power our business with renewable energy and also supports the development of a global clean energy infrastructure," says Van Lit. "With our latest program Planet Passionate, we are setting ourselves even more ambitious goals for the next decade in terms of energy, carbon and water reduction while improving the circularity of our products." If you would like to read in detail the results of the study "The real value of lean insulation," download the white paper "The real value of lean insulation" at  www.kingspan.com/nl/aanvraag-whitepaper .