Hello,
We are starting to get really frustrated... every builder tells us something different...
We want to build a 130sqm (1,399 sq ft) KfW 70 house with the living room facing south, and we are unsure whether to choose gas or an air source heat pump. Some providers, at almost the same price level, offer us air source heat pumps and claim that the annual costs are significantly (30%) lower compared to gas, while others doubt this.
We understand that insulation with gas/solar systems is usually better because an air source heat pump boosts efficiency more towards KfW 70 standards compared to gas/solar, which might argue in favor of gas. An air source heat pump might fail somewhat sooner, and in case of problems, you can usually get quick and competent local support with gas. With air source heat pumps, there could be more difficulties. Additionally, the noise of air source heat pumps (in our case about 3 meters (10 feet) from the neighbor) is not insignificant. Some say that sooner or later, everyone ends up having issues with neighbors for this reason.
We are interested in air source heat pumps with storage tanks from these providers: Vaillant, Mitsubishi Zubadan, and Rotex.
What we are really curious about is the annual cost for heating and hot water with both systems.
We live near Kassel.
What should we choose, and what would be cost-effective TODAY? What is your opinion on Vaillant?
Regards
Gigi
We are starting to get really frustrated... every builder tells us something different...
We want to build a 130sqm (1,399 sq ft) KfW 70 house with the living room facing south, and we are unsure whether to choose gas or an air source heat pump. Some providers, at almost the same price level, offer us air source heat pumps and claim that the annual costs are significantly (30%) lower compared to gas, while others doubt this.
We understand that insulation with gas/solar systems is usually better because an air source heat pump boosts efficiency more towards KfW 70 standards compared to gas/solar, which might argue in favor of gas. An air source heat pump might fail somewhat sooner, and in case of problems, you can usually get quick and competent local support with gas. With air source heat pumps, there could be more difficulties. Additionally, the noise of air source heat pumps (in our case about 3 meters (10 feet) from the neighbor) is not insignificant. Some say that sooner or later, everyone ends up having issues with neighbors for this reason.
We are interested in air source heat pumps with storage tanks from these providers: Vaillant, Mitsubishi Zubadan, and Rotex.
What we are really curious about is the annual cost for heating and hot water with both systems.
We live near Kassel.
What should we choose, and what would be cost-effective TODAY? What is your opinion on Vaillant?
Regards
Gigi
Not at all. Only a malicious neighbor who requests an inspection, but I dare say that neither the building authority nor the environmental agency will act on their own, because initially everyone assumes the citizen is innocent, unless an on-site inspection or justified suspicion suggests otherwise. Karsten
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R.Hotzenplotz30 Mar 2018 20:09From the wording of the legal text, I really can’t tell what the solar system is required to do and what it is not.
Regardless of how likely it is that one will be inspected or not, I want to build a house that complies with the law. If I wanted to build a non-compliant house, I would just install a gas heating system and leave out the solar panels. But the solar panels are only being installed because of the legal requirements. And I find it completely pointless to install them if they might be done in a way that is not compliant. Or am I misunderstanding this?
Regardless of how likely it is that one will be inspected or not, I want to build a house that complies with the law. If I wanted to build a non-compliant house, I would just install a gas heating system and leave out the solar panels. But the solar panels are only being installed because of the legal requirements. And I find it completely pointless to install them if they might be done in a way that is not compliant. Or am I misunderstanding this?
You must comply with your building permit, which includes the energy calculation and the associated materials to be used. If you build differently, the range of penalties can go from fines to a demolition order. However, the latter would certainly not be due to an incorrect solar panel.
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R.Hotzenplotz30 Mar 2018 20:20The general contractor does not provide any calculations. The architect once sent me the heating load calculation and, according to his own report, got into trouble with his superiors because an energy consultant found a suspected error in it, which I then passed on.
In principle, I am convinced that building with a general contractor was the right choice; however, when it comes to heating and building services, you definitely face the drawbacks of this model.
In principle, I am convinced that building with a general contractor was the right choice; however, when it comes to heating and building services, you definitely face the drawbacks of this model.
He should not withhold that from you. This is part of the approval documents. Are you the client, or is it a developer project? If you are the client, you are also responsible for ensuring construction follows the approved plans. In my calculation, which I don’t need to fully understand, it specifies exactly what U-value the panes and windows must have, how many square meters of solar panels need to be installed on the roof to meet the required share of renewable energy, how the masonry must be executed, and so on. I need to know this, and I have also paid for it.
Only if you are aware of this—and since you likely build differently for mainly aesthetic reasons—does it get more problematic. However, getting caught is still rather unlikely. Karsten
Only if you are aware of this—and since you likely build differently for mainly aesthetic reasons—does it get more problematic. However, getting caught is still rather unlikely. Karsten