ᐅ Is it better to estimate using KfW55 standards or the Energy Saving Regulation?
Created on: 24 Nov 2020 08:07
H
HausNebauBW160H
HausNebauBW16024 Nov 2020 08:07Hello,
we are planning a single-family house in southern Germany (Stuttgart area).
It is planned to have about 155m2 (1670 sq ft) of living space and be fully basemented, with the note that a basement room of approximately 50m2 (538 sq ft) should be heated.
Our question now is whether it is worth going through the bureaucratic and financial effort to obtain a KFW55 subsidy.
The basic specifications of the house according to the building description:
2 full floors with a hipped roof
Gas heating with solar thermal system for domestic hot water heating (unfortunately, I have no data regarding the area and output of the collectors)
Wall construction on ground floor and upper floor made of insulated bricks (U-value = 0.17 < 0.2 W/(m² K))
Basement insulation: 8cm (3 inches) Styrodur (extruded polystyrene)
Central ventilation system with 95% heat recovery
Windows currently have a Uw-value of 0.95 (>0.9 W/(m² K)), total window area about 57m2 (613 sq ft), total of 19 windows (excluding basement windows and one roof window)
Roof window (only an access hatch to get onto the roof) currently Uw = 1.2 (>1.0 W/(m² K))
Underfloor heating everywhere (except the heated basement room, which has two radiators)
What I find critical is that the general contractor (GC) is not very keen on building to KFW55 standards, as according to him it prolongs the construction time, involves more bureaucracy, and he would also be subject to external inspections.
We have to find an energy consultant ourselves. The ones contacted are not available until mid-January. Our offer from the GC is valid only until mid-December.
The elements to improve compared to current standards are: windows and roof window.
Probably the basement insulation and possibly the ceiling insulation to the attic (I could not find any information about this in the building description) also need improvement.
According to statements from other builders, the heated basement is also problematic – would it be possible, in order to meet the KFW subsidy requirements, to only install heating pipes in the basement floor now and keep the option open to add radiators later?
Now the question:
What would you do? Try to achieve KFW55 to get the subsidy of approximately €18,000 or build the house without it?
Thank you very much in advance for reading and for your opinions!
we are planning a single-family house in southern Germany (Stuttgart area).
It is planned to have about 155m2 (1670 sq ft) of living space and be fully basemented, with the note that a basement room of approximately 50m2 (538 sq ft) should be heated.
Our question now is whether it is worth going through the bureaucratic and financial effort to obtain a KFW55 subsidy.
The basic specifications of the house according to the building description:
2 full floors with a hipped roof
Gas heating with solar thermal system for domestic hot water heating (unfortunately, I have no data regarding the area and output of the collectors)
Wall construction on ground floor and upper floor made of insulated bricks (U-value = 0.17 < 0.2 W/(m² K))
Basement insulation: 8cm (3 inches) Styrodur (extruded polystyrene)
Central ventilation system with 95% heat recovery
Windows currently have a Uw-value of 0.95 (>0.9 W/(m² K)), total window area about 57m2 (613 sq ft), total of 19 windows (excluding basement windows and one roof window)
Roof window (only an access hatch to get onto the roof) currently Uw = 1.2 (>1.0 W/(m² K))
Underfloor heating everywhere (except the heated basement room, which has two radiators)
What I find critical is that the general contractor (GC) is not very keen on building to KFW55 standards, as according to him it prolongs the construction time, involves more bureaucracy, and he would also be subject to external inspections.
We have to find an energy consultant ourselves. The ones contacted are not available until mid-January. Our offer from the GC is valid only until mid-December.
The elements to improve compared to current standards are: windows and roof window.
Probably the basement insulation and possibly the ceiling insulation to the attic (I could not find any information about this in the building description) also need improvement.
According to statements from other builders, the heated basement is also problematic – would it be possible, in order to meet the KFW subsidy requirements, to only install heating pipes in the basement floor now and keep the option open to add radiators later?
Now the question:
What would you do? Try to achieve KFW55 to get the subsidy of approximately €18,000 or build the house without it?
Thank you very much in advance for reading and for your opinions!
P
pagoni202024 Nov 2020 08:22The consumer advice center offers a very good telephone information service on the topic of energy consulting. I initially contacted them, and it was really helpful. They might be able to assist you quite well. In principle, achieving KfW55 standards should be feasible.
We are building a single-family house with a basement and two full floors, aiming for KfW 55 standard. The additional cost for the measures needed to achieve KfW 55 is around €8,000. We received offers ranging from €7,000 to €9,500 from different general contractors.
This effectively leaves you with about €10,000. If you compare this with the interest rate on the KfW loan (0.95%) versus the interest rate you would get from a bank without KfW 55 (around 0.80%, maybe?), you would still have more than enough left—though the difference probably isn’t very significant.
Besides, you get a better insulated house and potentially save on heating costs. For me, building without KfW 55 wouldn’t even be an option.
This effectively leaves you with about €10,000. If you compare this with the interest rate on the KfW loan (0.95%) versus the interest rate you would get from a bank without KfW 55 (around 0.80%, maybe?), you would still have more than enough left—though the difference probably isn’t very significant.
Besides, you get a better insulated house and potentially save on heating costs. For me, building without KfW 55 wouldn’t even be an option.
I would also consider the KfW program, provided that the shorter KfW term in the financing does not cause issues with the monthly payments and the other loan conditions are not significantly better without KfW. The additional effort for KfW55 is definitely manageable, especially since a condensing boiler with solar thermal system and a ventilation unit are already planned.
Even without KfW: investing some effort into controlling avoidable thermal bridges and energy weak spots during construction is, in my experience, well worth the time for a trouble-free living experience later on. In these areas, the contractor sometimes prefers the simpler solution without detailed pre-planning, which can occasionally lead to less optimal energy performance – after all, it all ends up hidden beneath the attractive wall paint.
If underfloor heating is planned for the entire house, I would avoid installing a radiator in the basement if possible (this can require a mixing valve for two temperature levels, resulting in a more complex overall system).
Even without KfW: investing some effort into controlling avoidable thermal bridges and energy weak spots during construction is, in my experience, well worth the time for a trouble-free living experience later on. In these areas, the contractor sometimes prefers the simpler solution without detailed pre-planning, which can occasionally lead to less optimal energy performance – after all, it all ends up hidden beneath the attractive wall paint.
If underfloor heating is planned for the entire house, I would avoid installing a radiator in the basement if possible (this can require a mixing valve for two temperature levels, resulting in a more complex overall system).
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