The demonstration at the Schöck booth at the 21st International Passivhaus conference was graphic: One end of the concrete slab was refrigerated to the point that there was frost on it, condensed out of the air; the other side was warm to the touch. In between: a Schöck thermal break that separates the inside concrete from the outside.
The Schöck Isokorb® type CM is a load bearing thermal insulation element for cantilever concrete slabs such as balconies. The element transfers bending moment stress and shear forces. The integrated hanging and perimeter tensile reinforcement, fitted as standard, saves the unnecessary and costly use of extra stirrups or hooped mat.
We first showed them on TreeHugger almost a decade ago and asked then, why are these not required? It is such a huge cause of heat loss, of uncomfortable floors, of cracking ceilings, of mold. A Schöck representative told me at the time:
The customer wants hardwood flooring and a granite kitchen counter and for that they pay. No one is interested in the R-value for windows or the balcony. As long as the energy prices are so low in North America and the clients buy what the market provides, it is doubtful that there will be a change in thinking about energy efficiency.
Clearly nothing has changed. They are still not required in North America. They cannot even convince us with ice cream.
There are lots of different versions beside the concrete to concrete connector. I really like this one, which lets architects clip a steel and wood balcony onto a concrete building.
It’s crazy, that building codes would insist on insulation in walls yet permit these radiator fin balconies to just carry heat in and out of the building. If developers want balconies on their buildings they should have to build them properly.