Is new construction possible without solar and without a heat pump?

That's certainly true. I’ve also thought that from a financial perspective, it’s probably almost better to simply build according to the Energy Saving Ordinance without meeting the KFW standards. Financially, we wouldn’t be dependent on a KfW loan or any subsidy. We don’t have to build as cheaply as possible, but I also don’t want to spend money "unnecessarily" or "senselessly." I want it to be nice and comfortable, though. For us, that definitely includes a fireplace. And I would find a ventilation system very practical. Although I am at home almost all day, we still hardly ever open a window (except the patio door in summer and one window tilted open every night in the bedroom). And we suffer a lot from hay fever (I almost all year round) and the kids will probably get it too :-(. And I imagine that significantly fewer bugs come into the house if I keep the windows nicely closed.

You are not imagining the thing with the critters... less dirt and dust and all the other stuff that flies around gets into the house... the controlled residential ventilation filters everything out... But you urgently need to get out of the habit of leaving the windows tilted open...

Everything is possible. We are also building -new-. We initially wanted KFW70 with geothermal heat. but it was all a bit too expensive for us. now we are building without KFW (24 cm wall) and using a gas boiler. in addition, 2 collectors will be placed on the roof for hot water preparation. furthermore, there is a fireplace in our living room. that is enough. ;o)

Hi,
We are currently building a single-family house of approximately 145 sqm and have achieved KFW70 without a heat pump and without solar.
Relevant for this was the gas heating with underfloor heating and a ventilation system with heat recovery. Due to cost reasons, we decided on the decentralized ventilation system Lunos e2 with heat recovery.
We also placed value on a monolithic exterior wall, therefore Wienerberger Poroton T9 bricks with perlite filling (36.5 cm) were used for the exterior walls.

Hi, So we are currently building a single-family house of about 145 sqm and have achieved KFW70 without a heat pump and without solar. Relevant for this were the gas heating with underfloor heating and a ventilation system with heat recovery. We decided on the decentralized ventilation system from Lunos e2 with heat recovery because of the costs. We also placed value on a monolithic outer wall, therefore the Wienerberger Poroton T9 bricks with perlite filling (36.5 cm) were used for the outer walls.

Hello VillaMoTo,

I would be interested in more precise figures regarding insulation and technology - we are considering something similar but are not reaching KFW 70 with T8 bricks and a similar house size.

Regards, Kaz

Yeah, I don't know... it's all on Energieeinsparverordnung-online, you don't even have to search long... I took about 30 seconds...

I have a central ventilation system and I think you shouldn't build a new house according to the Energy Saving Ordinance standard without one... and also not with a decentralized system but ONLY with a central system, if you have the option...

No one can keep up the ventilation intervals if they're not home all the time... besides, a lot of energy is lost through window ventilation... and you have fresh filtered air in the house, that should help you allergy sufferers... however, the air will get very dry in winter, so you have to consider whether to use an enthalpy exchanger or possibly humidify the air in another way.

Why do you have to ventilate when you're not at home?
Moisture only occurs when you're home through breathing / showering / cooking...

More energy is lost operating a ventilation system than through simple window ventilation.

A ventilation system is and remains purely a matter of comfort; even energy recovery cannot compensate for the operational losses.