Flexible NOM concept based on second facade skin

The rollout of this innovative concept, 2nd skin, is an important reason for BIK bouw to join the Stroomversnelling sustainability initiative. "With 2nd skin, the client is completely unburdened, including proactive resident guidance," say project coordinators Tamara Verkleij and Jelske Sterkman of BIK bouw.

BIK stands for Building in Chain Cooperation: developments are not started and designed on a traditional basis, but with better products and concepts. "Among other things, this has led to the development of 2nd skin, a sustainability concept we developed with Climate Kic, TU Delft and chain partners including Sto and Itho Daalderop, starting from the Trias Energetica," says Verkleij.

2nd skin is carried out in occupied condition. The houses to be made more sustainable will have a new, well-insulated facade on the outside with built-in modules for ventilation, heating and cooling. "That facade connects to the existing facade, like a second skin," says Dr. K. K., the company's CEO. The product is ideally designed for the NOM renovation of porch apartments. "Basically, 2nd skin is suitable for all underlying facade materializations, usually a masonry facade. A second skin is mounted on the existing facade, composed of insulation material and decorative plaster or stone strips. The existing window frames are used as set frames."

Four variants

In this way, an Rc value of 4.5 to 6 (facade and roof) is achieved. The concept has four variants. 'Premium' involves preservation in steps (low investment with high energy savings/C0₂-savings: 45%), 'Hybrid' is a low-gas package combined with a boiler, heat pump and PVT panels (C0₂-savings: 63%) and 'All Electric' is completely gasless and features both PV and PVT panels (C0₂-savings: 93%). The last variant is 2nd skin 'Zero Energy' and involves generation based on Zero-in-the-Meter. In this variant, the NOM Keur of Stroomversnelling can be obtained. This then also allows the Energy Performance Fee (EPV) to be applied: landlords can charge tenants for NOM performance.

On-site customization

Guidance toward the residents of the homes is an integral part of the concept. Sterkman: "We involve residents in the process and work with regular partners from initiative to management. We set up a model home and provide complete resident guidance; we call this the 'customer journey'. With this we relieve the client - often a housing corporation, sometimes an association of owners, from start to finish. Due to scale and modular thinking, we can offer proven products more cheaply. The components are fully worked out in our reference details and technical description, as well as in our VABI software and the multi-year maintenance plan (MJOP). 2nd skin was developed as a low-maintenance concept." However, implementation and guidance are customized processes in co-creatorship: 2nd skin is not a ready-made product, but customization on site with fixed components. "And good resident guidance is an important condition in social sustainability projects to achieve 70% support."

The first realized project under the name 2nd skin concerns 12 porch apartments on the Soendalaan in Vlaardingen for housing corporation Waterweg Wonen. The different variants have been extended in steps to 'Zero Energy'. The 2nd skin ensures good insulation and airtightness. In the new window frames comes three-layer insulating glass. The roof is covered with solar panels. After making the building more sustainable, it will no longer have a gas connection. Instead, a multi-heat pump system will provide heating and hot water. Sterkman: "We are now scaling up with several projects, including 134 homes on the Burgemeester Pruissingel in Vlaardingen. 2nd skin is a concept that is constantly evolving, both technically and for residents and clients."