Hello everyone,
I just registered here because I have a topic that is very important to me. If this topic is in the wrong forum, I kindly ask the moderator to move it if necessary.
We are planning to build this year and are currently (hopefully) at the end of the planning phase. The house will be built according to the 2012 energy saving ordinance.
We are planning a house with around 170-190 sqm (1,830-2,045 sq ft) of living space, which will have a basement built partially above ground into a hillside. Besides two smaller rooms and a utility room, the basement includes a double garage. The house will be heated with geothermal energy in the future.
Right now, we are refining the budget, which has gotten somewhat out of control (10% deviation from the target). We have already made some contributions ourselves, cut items, and reduced the size.
Our builder recently suggested reconsidering the planned KfW 70 standard because the additional investments would only pay off in the very long term (30 to 50 years).
Some background: Whether we keep or abandon the KfW 70 standard, the house will definitely have a geothermal heating system, as well as the planned bricks (thickness and lambda value) required for the KfW standard.
The following (cut) items are under discussion:
- The roof insulation will be done with 180 mm (7 inches) instead of 220 mm (9 inches) thickness (same lambda value 0.35) – 220 mm is actually necessary given the size of the house
- The cladding of the reinforced concrete parts will be reduced by about 2 cm (0.8 inches) of polystyrene
- A different insulation for the floor slab will be used (the new insulation has a worse lambda value)
These changes would reduce construction costs by 8,000 Euros but would mean losing the KfW 70 standard.
Still, I hesitate to give up the KfW 70 standard for the following reasons:
My questions to you are:
Thank you very much for your feedback.
f-pNo
I just registered here because I have a topic that is very important to me. If this topic is in the wrong forum, I kindly ask the moderator to move it if necessary.
We are planning to build this year and are currently (hopefully) at the end of the planning phase. The house will be built according to the 2012 energy saving ordinance.
We are planning a house with around 170-190 sqm (1,830-2,045 sq ft) of living space, which will have a basement built partially above ground into a hillside. Besides two smaller rooms and a utility room, the basement includes a double garage. The house will be heated with geothermal energy in the future.
Right now, we are refining the budget, which has gotten somewhat out of control (10% deviation from the target). We have already made some contributions ourselves, cut items, and reduced the size.
Our builder recently suggested reconsidering the planned KfW 70 standard because the additional investments would only pay off in the very long term (30 to 50 years).
Some background: Whether we keep or abandon the KfW 70 standard, the house will definitely have a geothermal heating system, as well as the planned bricks (thickness and lambda value) required for the KfW standard.
The following (cut) items are under discussion:
- The roof insulation will be done with 180 mm (7 inches) instead of 220 mm (9 inches) thickness (same lambda value 0.35) – 220 mm is actually necessary given the size of the house
- The cladding of the reinforced concrete parts will be reduced by about 2 cm (0.8 inches) of polystyrene
- A different insulation for the floor slab will be used (the new insulation has a worse lambda value)
These changes would reduce construction costs by 8,000 Euros but would mean losing the KfW 70 standard.
Still, I hesitate to give up the KfW 70 standard for the following reasons:
- I cannot estimate how much energy can actually be saved by keeping the measures under discussion (is the claim of paying off within up to 50 years accurate?)
- The KfW financing is about 1% cheaper than a normal loan with a 10-year fixed interest rate – meaning for 50,000 Euros, you save around 4,500 Euros in interest over 10 years
- Giving up the KfW 70 standard might reduce the potential resale value
My questions to you are:
- What do you think about this?
- If I decide to go with KfW 70: Are the stated 50 years (or possibly 30 years) for the measures to pay off realistic?
Thank you very much for your feedback.
f-pNo
F
Fabiorella26 Jun 2013 08:19f-pNo schrieb:
Since the house’s final design (dimensions, square meters, etc.) was not confirmed until last weekend and changes were still being made, the corresponding calculation could not be carried out yet. From my perspective, this is understandable—you need to know whether to calculate the heating demand for 190 or (now probably final) 170 sqm (1830 sq ft).
The preliminary design of the house will now go to the structural engineer for the “final review.” After that, the heating/energy demand calculation will be performed.
Then it should also be clear which measures will actually be implemented or not, and what effect this will have. Just for understanding:
You now have 20 sqm (215 sq ft) less; that should also be noticeable in the cost plan, right?
Regards