Hello,
we received a quote for a single-family house built according to the Energy Saving Ordinance from a builder, who offers the following exterior wall construction:
- 17.5 cm (7 inches) aerated concrete
- Mineral fiber insulation mat with a minimum thickness of 14 cm (5.5 inches) according to the thermal protection certificate (thermal conductivity 0.035 W/mK)
- 11.5 cm (4.5 inches) facing brick
What is the evaluation of these materials regarding thermal insulation and soundproofing?
Are there quality differences in this construction as well?
For an additional cost of €2,000, the following upgrades are available:
- 140 mm (5.5 inches) cavity insulation with a thermal conductivity of 0.035 W/mK in the facing brickwork
- 180 mm (7 inches) mineral wool insulation with a thermal conductivity of 0.035 W/mK in the rafter area
- 240 mm (9.5 inches) mineral wool insulation with a thermal conductivity of 0.035 W/mK in the collar beam area
- 100 mm (4 inches) polystyrene rigid foam insulation with a thermal conductivity of 0.035 W/mK under the ground floor screed
With a solar system for domestic hot water preparation, which costs almost €7,000, KfW 70 standard could be achieved.
What do you think about this?
Is the standard specification sufficient, and is the upgrade worth the additional cost?
we received a quote for a single-family house built according to the Energy Saving Ordinance from a builder, who offers the following exterior wall construction:
- 17.5 cm (7 inches) aerated concrete
- Mineral fiber insulation mat with a minimum thickness of 14 cm (5.5 inches) according to the thermal protection certificate (thermal conductivity 0.035 W/mK)
- 11.5 cm (4.5 inches) facing brick
What is the evaluation of these materials regarding thermal insulation and soundproofing?
Are there quality differences in this construction as well?
For an additional cost of €2,000, the following upgrades are available:
- 140 mm (5.5 inches) cavity insulation with a thermal conductivity of 0.035 W/mK in the facing brickwork
- 180 mm (7 inches) mineral wool insulation with a thermal conductivity of 0.035 W/mK in the rafter area
- 240 mm (9.5 inches) mineral wool insulation with a thermal conductivity of 0.035 W/mK in the collar beam area
- 100 mm (4 inches) polystyrene rigid foam insulation with a thermal conductivity of 0.035 W/mK under the ground floor screed
With a solar system for domestic hot water preparation, which costs almost €7,000, KfW 70 standard could be achieved.
What do you think about this?
Is the standard specification sufficient, and is the upgrade worth the additional cost?
I have now received an offer from another builder:
Instead of 17.5cm (7 inches) aerated concrete, they use a porous clay brick with the same thickness of 17.5cm (7 inches). Otherwise, the wall structure is the same. The standard features include underfloor heating, triple glazing (U-value = 0.7), and a solar thermal system. KfW 70 efficiency is guaranteed—without any additional cost! Strip foundations are poured up to 20cm (8 inches) above ground level, with 10cm (4 inches) of gravel or sand placed under the base slab. Is this common practice and does it make sense?
In the first offer, the underfloor heating adds nearly €7,500, and KfW 70 with solar costs almost another €8,000. The foundation there only has a 5cm (2 inches) lean concrete blinding layer. The total prices of both builders don’t differ much; the first offer includes more electrical outlets and higher/more expensive tiles, but only double glazing with a U-value of 1.1.
What do you think about these two offers?
Instead of 17.5cm (7 inches) aerated concrete, they use a porous clay brick with the same thickness of 17.5cm (7 inches). Otherwise, the wall structure is the same. The standard features include underfloor heating, triple glazing (U-value = 0.7), and a solar thermal system. KfW 70 efficiency is guaranteed—without any additional cost! Strip foundations are poured up to 20cm (8 inches) above ground level, with 10cm (4 inches) of gravel or sand placed under the base slab. Is this common practice and does it make sense?
In the first offer, the underfloor heating adds nearly €7,500, and KfW 70 with solar costs almost another €8,000. The foundation there only has a 5cm (2 inches) lean concrete blinding layer. The total prices of both builders don’t differ much; the first offer includes more electrical outlets and higher/more expensive tiles, but only double glazing with a U-value of 1.1.
What do you think about these two offers?
I don’t know which type of Poroton brick Helma uses, and the sales representative either couldn’t or wouldn’t tell me.
With a 17.5cm (7 inch) brick combined with insulation and a facing brick, does aerated concrete even make sense?
Is there enough sound insulation? How is it inside the rooms then?
I’m really uncertain which material I should prefer.
The fact is, I unfortunately have to build with a facing brick...
With a 17.5cm (7 inch) brick combined with insulation and a facing brick, does aerated concrete even make sense?
Is there enough sound insulation? How is it inside the rooms then?
I’m really uncertain which material I should prefer.
The fact is, I unfortunately have to build with a facing brick...
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