In Vlaardingen, Netherlands, a unique deep retrofit pilot project is taking place: the 2nd Skin project . But what is 2nd Skin? Onno de Wal, Director of BIK bouw, answers that question.
What is the principle behind 2nd Skin?
Onno de Wal: The name is pretty self-explanatory. We add a second skin to a building’s envelope. This additional envelope is a smart solution to solve the energy efficiency issues of aging buildings. 2nd Skin is very flexible as it is based on the Sto Therm Classic technology. By using this product, we are flexible when it comes to dimensions, insultation value and aesthetic finish. It also opens great possibilities for the architects to imagine new shapes to design. Last but not least, Sto Therm Classic is light, which allows us to add very few weight on the existing structure. The new frames constrain three-layer insulation glass. It also comes with solar panels on the roof for the building to switch toward green energies.
What are the benefits of using 2nd Skin rather than a “standard” thermal renovation process?
Onno de Wal: First it’s quick, only 2 to 3 days, and the residents can stay at home during the process, as only a few steps of the renovation process require to work indoor. Second, this is a very affordable investment: the housing expenses for residents won’t go up. Partner TU Delft and Client Waterweg Wonen will monitor the energy usage of the building to help tenants to regulate and keep their energy bill as low as possible. Third benefit: it’s highly replicable to many buildings, enabling a massified renovation of housings in the Netherlands. The Vlaardingen pilot project is meant to demonstrate that replicability, technically and financially. Fourth benefit: 2nd skin flexibility leaves the possibility for future works on the building (extension, new openings…)
Is the massification of renovation the challenge that inspired 2nd Skin?
Onno de Wal: Yes, most definitely. Our motto could be “Simplify and scale up”. It’s a huge challenge in the Netherlands, as it is in many European countries. For this pilot project we focused on one of the 5 types of Dutch housings: stacked houses. No solution currently exists to transition this type of housings toward energy efficiency… until now! There are around 500,000 housings like that in the Netherlands, which adds to the challenge. But we need to move forward in massifying renovation if we want to reach the EU goal of all existing buildings renovated by 2050. And ultimately we can imagine spin-offs of 2nd skin solutions for other types of housings.
And where is the pilot project at now?
Onno de Wal: The Vlaardingen project is a cooperation of several partners: Waterweg Wonen Housing Cooperation owns the housings to be renovated, BIK bouw, Provincie Utrecht, TU Delft, TU Munchen, Sto Isoned, Itho Daalderop and Kingspan came up with the 2nd Skin concept, and BTA supports the development. This pilot project covers 12 homes to be refurbished to become Zero Energy buildings. While the buildings are unique, they are designed the same way and use a circulating heat system for heating. From measures on one building we can extrapolate data for the 11 others to achieve thermal comfort for all of them. Tenants have been involved from the very start of the pilot – are very enthusiastic and co-operative.
How does BTA support this project?
Onno de Wal: Climate-KIC BTA opened up its network and ‘de-risked’ the innovation. That speeded things up. But what really gave 2nd Skin wings was that Climate-KIC ‘pushed’ the start-up over its own borders of comfort which helped the team of 2nd Skin to find a way into the market. They will be of great help when we get to scale up to the whole country and even beyond.