Insulate the roof: flakes, panels or wool

Hello.

We will be building a single-family house in 2016. Our budget is tight. We have 300k€ available including a buffer for 160 sqm (without outdoor facilities, no basement, no carport). Currently, our architects are preparing the tenders for the individual trades. As evident from the subject line, we now have to decide soon on the insulation of the roof. For the thermal insulation certificate according to the Energy Saving Ordinance 2014, 24 cm of mineral wool 035 was calculated for the roof. However, our architects recommend using blown insulation instead. This is said to be better especially for summer thermal protection. Since some of our rooms are very tall and will extend up to under the roof, this argument could indeed be important. However, we have concerns regarding the higher costs of blown insulation and also fear that a blown insulation might possibly sag downwards (gable roof) and then leave a gap at the ridge of the roof.

What do you think? Are there any experiences regarding costs and "compression" of blown insulation?

Thanks and regards.

Really no experience with [Flockendämmung] in the roof?

Thanks and regards.

This works if you know the entire roof structure, then you can forget about the underlay [Unterspannbahn] (because it’s supposed to be cheap). And on the room side, precautions must also be taken so that the whole mess does not bulge. Then flakes have a WLG of 0.39 or 0.40 somewhere, depending on approval. This means that improvements must also be made.

Although it doesn’t quite belong to the topic, I still have a few questions about your financial leeway. Are the 300K€ planned for the house and land, or just for the house? Are the 160m² calculated with or without the walls?

This doesn’t quite belong to the topic. But I still have a few questions about your financial scope. Are the €300K planned for the house and land, or just for the house? Are the 160 m² calculated with or without the walls?

The €300K is only for the house. The 160 m² is living space (758 m³ enclosed space). We already own the land.

3000 euros for 200 sqm open blown.....