ISO-BLOCO ONE - the first multi-function joint sealing tape certified suitable for passive energy houses

During the International Passive Energy House Conference in Darmstadt/Germany, a joint sealing tape was awarded the “certified passive energy house component” certificate in the category “Airtight systems/window connection” for the first time. The product from ISO-Chemie was convincing throughout the test procedure, and is the only joint sealing tape so far to receive the renowned award from the Passive Energy House Institute Dr. Feist Darmstadt (PHI).

As an independent body, the PHI tests and certifies products with a view to their suitability for use in passive energy houses. Products that are awarded the “component suitable for passive energy houses” certificate have been tested in accordance with standard criteria, are comparable in terms of key values and have excellent energy efficiency. The use of certified passive energy house components such as ISO-BLOCO ONE help make the planning of buildings easier and contribute significantly to guaranteeing the perfect function of a passive energy house and maintaining it long-term.


After the IN FRONT OF WALL INSTALLATION SYSTEM ISO-TOP WINFRAMER, the multi-function joint sealing tape ISO-BLOCO ONE is another product from the ISO³-WINDOW SEALING SYSTEM from ISO-Chemie to be recognised by the PHI as a “certified passive energy house component” in the window connection category. The multi-function joint sealing tape, which has been successful on the market for years, has received the notable award for good reason. ISO-BLOCO ONE stands out on account of its excellent functional characteristics and is the only sealing tape to fully meet the high demands of the PHI so far.




ISO-BLOCO ONE is an “all-in-one tape” that combines all the requirements of EnEV- and RAL-conform fitting in a single product. This makes it particularly suitable for the reliable, straightforward and time-saving sealing of window and door connections. The intelligent joint sealing tape works according to the 3-level principle of the RAL “installation guide”. On the outside, the BG 1 and BG R-tested multi-function joint sealing tape guarantees above-average resistance to driving rain with more than 1,000 Pa. The middle layer has a thermal and sound insulating effect, and on the inside the tape has a revolutionary low a-value of practically zero, making it 100% airtight and vapour-resistant – an aspect that is particularly important in passive energy houses. The excellent airtightness values contribute to reducing the convective heat losses, scoring points on the building energy assessment and returns excellent results in the blower-door test. This was one of the factors resulting in the product’s “certified passive energy house component” award in the category “Airtight systems/window connection”.


Compared with other multi-function joint sealing tapes, ISO-BLOCO ONE also stands out thanks to its extremely favourable sd-value gradient of 50:1. Such a large vapour diffusion gradient permits efficient transportation  of humidity to the outside and faster drying of the joints, in line with the “inside tighter than outside” principle of the “Installation guide for the installation of windows and doors” published by the the RAL quality association “Joint sealing components and systems”.


In addition to the passive energy house certificate, the multi-function joint sealing tape ISO-BLOCO ONE has received a host of other important awards such as the RAL quality mark “Joint sealing components and systems”. The RAL quality mark guarantees outstanding, durable quality and the planning reliability related to this, because products that have been awarded the RAL quality mark must prove during regular external and internal audits that they have a consistent quality that goes far beyond the requirements of the German industrial standard DIN.


In addition, ISO-BLOCO ONE was confirmed as “very low-emission” and thus bears the GEV EMICODE® mark. This premium classification by the Association for the Control of Emissions in Products for Flooring Installation, Adhesives and Building Materials e.V. (GEV) means maximum possible protection against ambient air contamination. Both users and clients are guaranteed that the product does not emit hazardous substances into the ambient air and does not represent any risk to health.


Overall, these outstanding product characteristics make the energy-efficient multi-function joint sealing tape ISO-BLOCO ONE second to none on the market, and completely justify the passive energy house certificate.


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