Hello forum, I hope you can help me.
We are planning a roof renovation with an external rafter insulation; insulation boards will be installed from the outside up to the roof ridge.
Our attic is heated, but the loft space above is not, and it is hardly accessible, so it does not make sense to convert it. When we moved in five years ago, I already insulated the collar beam layer with about 200mm (8 inches) of mineral wool and completely relaid all boarding myself. At that time, the electrician also replaced all wiring in the crawl space.
Our energy consultant applied in time for a loan from the KfW bank as funding for individual measures, and we now have a quote from a timber construction company, which also showed us a reference project, so everything seemed fine.
After reviewing the contractor’s offer, our energy consultant informed us that insulation of the loft area is missing. The KfW bank requires that in the case of an unheated loft space, it must also be insulated to a U-value of 0.14.
However, insulating this area would mean rerouting cables in the loft, removing the floor covering again, and it would really cost money while providing almost no energy benefit. The room there is just over 1.60m (5 feet 3 inches) high.
The energy consultant could not provide a written reference for this requirement, only pointing to a sentence in the application: “Pitched roofs and related collar beam layers.” Unfortunately, the KfW bank’s technical data sheets do not clarify this further.
We contacted the KfW bank by phone but did not receive a clear, binding answer. One KfW representative jokingly suggested that if we installed a radiator up there, we wouldn’t have to insulate... Of course, if an inspection takes place, the KfW inspector will probably find that equally funny and could cancel our loan.
I can understand the need to insulate the collar beam layer if the space is entirely unheated and uninsulated. That’s why we did it ourselves after all, but this requirement in our case is complete nonsense.
The energy consultant naturally prefers to take the safe route, and the carpenter seems cautious about commenting.
I would be glad to hear about your experiences and views on this topic. We are a bit desperate; we are happy to have secured the favorable loan terms but are struggling with this requirement.
We are planning a roof renovation with an external rafter insulation; insulation boards will be installed from the outside up to the roof ridge.
Our attic is heated, but the loft space above is not, and it is hardly accessible, so it does not make sense to convert it. When we moved in five years ago, I already insulated the collar beam layer with about 200mm (8 inches) of mineral wool and completely relaid all boarding myself. At that time, the electrician also replaced all wiring in the crawl space.
Our energy consultant applied in time for a loan from the KfW bank as funding for individual measures, and we now have a quote from a timber construction company, which also showed us a reference project, so everything seemed fine.
After reviewing the contractor’s offer, our energy consultant informed us that insulation of the loft area is missing. The KfW bank requires that in the case of an unheated loft space, it must also be insulated to a U-value of 0.14.
However, insulating this area would mean rerouting cables in the loft, removing the floor covering again, and it would really cost money while providing almost no energy benefit. The room there is just over 1.60m (5 feet 3 inches) high.
The energy consultant could not provide a written reference for this requirement, only pointing to a sentence in the application: “Pitched roofs and related collar beam layers.” Unfortunately, the KfW bank’s technical data sheets do not clarify this further.
We contacted the KfW bank by phone but did not receive a clear, binding answer. One KfW representative jokingly suggested that if we installed a radiator up there, we wouldn’t have to insulate... Of course, if an inspection takes place, the KfW inspector will probably find that equally funny and could cancel our loan.
I can understand the need to insulate the collar beam layer if the space is entirely unheated and uninsulated. That’s why we did it ourselves after all, but this requirement in our case is complete nonsense.
The energy consultant naturally prefers to take the safe route, and the carpenter seems cautious about commenting.
I would be glad to hear about your experiences and views on this topic. We are a bit desperate; we are happy to have secured the favorable loan terms but are struggling with this requirement.
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