B
Bulla20006 Sep 2010 10:06Hello.
We have now received several quotes for our planned single-family house (BT). Two of them are based on thin exterior walls with external thermal insulation composite systems (ETICS), while two want to build the shell using Wienerberger T10 bricks with a thickness of 36.5cm (14.4 inches). I definitely prefer a thick wall without plastic-based materials.
Therefore, I favor a monolithic construction method. The current quote includes the Wienerberger T10 brick. Over the weekend, I looked through Wienerberger brochures, especially about the T9 with the V-Plus system, and also read about it online.
The thermal insulation values are clearly better (between T10 and T9). What kind of additional cost can I expect for this? The house will be about 9x9m (29.5x29.5 feet) with a basement, ground floor, and attic. An approximate figure would be sufficient.
Is the extra cost worth it? I would rather skip a "nice-to-have" feature like a chimney flue and instead invest in the exterior masonry if the budget allows.
We have now received several quotes for our planned single-family house (BT). Two of them are based on thin exterior walls with external thermal insulation composite systems (ETICS), while two want to build the shell using Wienerberger T10 bricks with a thickness of 36.5cm (14.4 inches). I definitely prefer a thick wall without plastic-based materials.
Therefore, I favor a monolithic construction method. The current quote includes the Wienerberger T10 brick. Over the weekend, I looked through Wienerberger brochures, especially about the T9 with the V-Plus system, and also read about it online.
The thermal insulation values are clearly better (between T10 and T9). What kind of additional cost can I expect for this? The house will be about 9x9m (29.5x29.5 feet) with a basement, ground floor, and attic. An approximate figure would be sufficient.
Is the extra cost worth it? I would rather skip a "nice-to-have" feature like a chimney flue and instead invest in the exterior masonry if the budget allows.
B
Bauexperte6 Sep 2010 10:56Hello,
As a point of reference: we build with aerated concrete PP2-035, lambda 0.090 W/(mK) – without external thermal insulation composite system (ETICS/EIFS) – and achieve a blower door test value of 0.7/h (the blower door test measures the airtightness of a building or apartment).
The most important limit values for residential buildings are: a value below 3/h is required, for example, by ÖNORM and should definitely be met in any house construction. For buildings with ventilation systems, an nL50 value below 1.5/h is mandatory (otherwise too much air leaks through joints, reducing the effectiveness of the ventilation system). For passive houses, the threshold is set even lower, with a maximum value of 0.6/h.
With the achieved value of 0.7/h, the homeowner – if no ventilation system is installed – must ventilate frequently and regularly, as the single-family house is very airtight.
You will – most likely – achieve this value with the T9 as well.
Kind regards
Bulla2000 schrieb:
…The thermal insulation values are now significantly better (between T10 and T9). What price increase should I expect for that? The house will be about 9x9m (30x30 feet) in size with a basement, ground floor, and upper floor. An approximate figure would be sufficient… Is the extra cost worth it? I would rather skip a "nice-to-have" feature like the chimney flue and invest in the exterior wall construction if it’s financially feasible.
As a point of reference: we build with aerated concrete PP2-035, lambda 0.090 W/(mK) – without external thermal insulation composite system (ETICS/EIFS) – and achieve a blower door test value of 0.7/h (the blower door test measures the airtightness of a building or apartment).
The most important limit values for residential buildings are: a value below 3/h is required, for example, by ÖNORM and should definitely be met in any house construction. For buildings with ventilation systems, an nL50 value below 1.5/h is mandatory (otherwise too much air leaks through joints, reducing the effectiveness of the ventilation system). For passive houses, the threshold is set even lower, with a maximum value of 0.6/h.
With the achieved value of 0.7/h, the homeowner – if no ventilation system is installed – must ventilate frequently and regularly, as the single-family house is very airtight.
You will – most likely – achieve this value with the T9 as well.
Kind regards
B
Bulla20006 Sep 2010 12:12I know the advantages, thanks Bauexperte. I just wanted your opinion on whether it’s better to invest the money in a T9 brick instead of a T10. A pure brick wall without artificial insulation is also better for diffusion, right?
B
Bauexperte9 Sep 2010 11:52Hello,
Well, in a way, both are right because you can’t reach KfW70 efficiency with the brick alone; besides the triple glazing, a certain share of renewable energy is also required => the annual primary energy demand must only be 70% of the energy demand of a comparable new building.
Kind regards
Bulla2000 schrieb:
The other competitor just said that with the T10 at 36.5cm (14 inches) you would never achieve a KfW70. My other favorite builder says the T10 is still the most cost-effective brick for a KfW70 house.
Well, in a way, both are right because you can’t reach KfW70 efficiency with the brick alone; besides the triple glazing, a certain share of renewable energy is also required => the annual primary energy demand must only be 70% of the energy demand of a comparable new building.
Kind regards
B
Bulla20009 Sep 2010 13:32Sure. For example, besides the insulation between rafters, D. also included a 25cm (10 inches) thick insulation below the rafters (U-value 0.19) in the offer. Additionally, the foundation slab in the basement, the ground floor, and basement walls will be fully insulated, of course. The new AI house control system will be installed, meaning an air-source heat pump with controlled mechanical ventilation, with a performance coefficient of 1:4.3. Solar is not worth it as an extra option. Standard windows have a Ug value of 0.5 (Climatop glass, frames Thyssen-Inoutic series: Prestige 176.6 C).
I just want to be sure, because you often read that if the construction is monolithic, then a 36.5cm (14 inches) thick wall does not meet the KfW 70 standard. However, the T10 data sheet explicitly states a thermal conductivity of 0.10 and suitability for the 2009 Energy Saving Ordinance and KfW efficiency houses.
In any case, this needs to be included in the contract.
How was it regarding the KfW funding? The builder prepares an energy calculation, which must be submitted to the KfW along with the loan application via my savings bank. Then, at the end, when the house is completed, a certified person (probably the builder as well?) must confirm that the KfW limits have been met... right?
I just want to be sure, because you often read that if the construction is monolithic, then a 36.5cm (14 inches) thick wall does not meet the KfW 70 standard. However, the T10 data sheet explicitly states a thermal conductivity of 0.10 and suitability for the 2009 Energy Saving Ordinance and KfW efficiency houses.
In any case, this needs to be included in the contract.
How was it regarding the KfW funding? The builder prepares an energy calculation, which must be submitted to the KfW along with the loan application via my savings bank. Then, at the end, when the house is completed, a certified person (probably the builder as well?) must confirm that the KfW limits have been met... right?
B
Bulla20009 Sep 2010 15:15I have now seen shocking figures: with a T10 block at 36.5cm (14.4 inches) thickness, you will never meet the 2009 Energy Saving Ordinance standard, let alone KfW70.
With the T9 block, you just barely meet the 2009 Energy Saving Ordinance.
So why does company D. use this block if they know I want to achieve KfW70 standard?
To me, this means either thinner walls with added plastic insulation on the outside or building a cavity (double) wall. Both options are significantly more expensive and therefore unaffordable. Is building a house off the table...?
With the T9 block, you just barely meet the 2009 Energy Saving Ordinance.
So why does company D. use this block if they know I want to achieve KfW70 standard?
To me, this means either thinner walls with added plastic insulation on the outside or building a cavity (double) wall. Both options are significantly more expensive and therefore unaffordable. Is building a house off the table...?
Similar topics