ERAflat retains characteristic end walls

It looks like the floors are running through again

Typical of the 504-unit ERAflat at Schermerhoek in Capelle aan den IJssel are the horizontal bands on the end walls. Even after the large-scale renovation of this flat, the characteristic floor bands visually reappear.

The huge concrete apartment is being dramatically improved and made more sustainable. This and other ERA flats were built in the 1960s and 1970s, when the housing shortage was very high. At that time, contractor J.P. van Eesteren invented the tunnel casting method, a revolutionary new system for faster construction. The system was given the name Van Eesteren Rationale Approach (ERA). In recent years, a thorough renovation of the dozens of ERA flats has begun, making the homes much more energy efficient and comfortable. 

Thirteenth flat

On the outside, this included insulating and finishing the end walls of the Schermerhoek apartment block. From the first floor, IJsselmonde applied a new shell by means of a facade insulation system and then finished it with mineral facade strips from Sto. The two-meter-high plinth consists of storerooms and was not insulated because it does not add any energy value. As a result, the original facade remains visible there. 

According to Jacco Oostenbrug of IJsselmonde, the 14-centimeter thick insulation package is now a regular insulation thickness. The flat at Schermerhoek is the thirteenth ERAflats the company is tackling for Team ERAflats, a joint venture of ERA Contour and Smits Vastgoedzorg.

Boring? "Definitely not," says Oostenbrug. "It remains fun. Every end façade is a challenge, and big projects like this one we can handle well. We still get happy with the result we put down."

Scaffolding above water

Before that happens, IJsselmonde will take care of the additional scaffolding and examine the condition of the cavity wall anchors. The anchors connect the brick outer cavity wall to the inner cavity wall and thus stabilize the outer wall. Oostenbrug: "Those anchors can rust quite a bit, and it may even be the case that too few anchors were installed in the past. That can cause dangerous situations." In this apartment building, anchors had to be added first before the facade insulation could be installed. So structurally, the end wall was also completely renovated.

It was a lot more difficult to build scaffolding on the side where the end wall borders the water. "A substructure had to be built in the water for that, so that we could put the scaffolding on it," explains Dirk Jan van der Poel, business manager at IJsselmonde. "We've been busy with the contractor's construction team coming up with a plan for that and having a steel work floor designed by the structural engineer." The fourteen-story high scaffolding will then be placed on top of that. Not surprisingly, a great deal of coordination is required. IJsselmonde had additional scaffolding drawings made to prepare the construction as well as possible. 

Visible floor bands

Characteristic of the ERAflats are the horizontal, light bands in the end walls. These are the concrete floors that have been poured through to the outside. They make the fourteen floors highly visible from the outside. "But energetically the bands are not so beneficial. They easily pull the outside temperature inside," explains Niels Kempen of Sto Isoned. Still, the municipality wanted to see the tires on the end walls. Kempen: "That's why 30-centimeter-wide mock strips of Sto Deco sheet material were installed. These insulate well and you remove the thermal bridge as a result." The strips were glued to the facade insulation system, after which the facade strips were applied above and below the strips. In this way, the floors appear to continue and the existing appearance of the apartment building is changed as little as possible. 

Hooked up early

"That the bands of the storey floors on the end walls would be visible again after the renovation was a wish from the Schermerhoek project team," says Teun Heuvelman, work planner at ERA Contour. "And also that the color of the bands and façade strips had to be close to the original colors. We gave those wishes to A3 architects." Mineral façade strips have also been used in the renovations of other ERA flats. Heuvelman explains, "Mineral façade strips are light, can be applied quickly and they have improved considerably over the years aesthetically." 

Heuvelman is pleased with the result of the end walls. "IJsselmonde is a party we have known for some time. With this project, they got involved early on. That is certainly beneficial, because IJsselmonde itself makes the drawings and calculations of the scaffolding and has also contributed ideas about the supporting structure." 

Fire line

The special thing about the construction of this apartment on Schermerhoek is that the escape stairwells are on the outside of the end wall. Those stairwells also had to be included. "A laborious head," says Van der Poel. "You have to go around the corner and onto the balcony to be able to take those pieces of facade with you properly as well. Also, the fire line, which is normally inside, is on the outside of this apartment building. We therefore worked neatly around it with the insulation package."

So a lot of meters were made in a short time. Van der Poel: "That is also what we are known for: putting in such large heads quickly and professionally. Every end wall is a challenge. And then when the scaffolding is gone, it looks super cool again. And so tight!"