Bungalow half 8m² KfW70 without ventilation / basement, Y-Tong

We would like to purchase and have built a newly constructed, fully planned half of a bungalow without a basement with a hip roof.

Please excuse any incorrectly spelled or named technical terms – we are just laypeople.

After quite a bit of reading, we are now in the "phase of uncertainty," surely familiar to many here ;-)

Therefore, a few pieces of information about the project:

Hip roof bungalow half

- Building foundation made of glass foam gravel with reinforcement, compacted, concrete, base slab moisture-proof covered (is this certainly the slab?)

- 6 cm insulation layer, 6 cm floating screed

- Exterior shell 36.5 cm aerated lightweight concrete in system blocks or units Y-Tong plan blocks W-PPW 2-040, MSH steel profile 120/80/5 as support in the bathroom (ceiling) window area – what for?

- Double reinforcement with mesh and scratch plaster on the outside

- Windows UW=1.0, triple glazing

- All rooms have windows (living kitchen, utility room, bedroom, bathroom)

- Room height approx. 2.5 m, house height up to the ridge 6.11 m

- District heating (underfloor heating in all rooms)

- Attic accessible via hatch, insulation between rafters in the roof

- Usable floor area 114 m² (footprint 88 m²)

These are the general pieces of information. More gladly upon request.

Through this forum, I came across passive/active ventilation (and of course KfW 70 because of the subsidy ;-)

Now the question about active/passive ventilation. Is this necessary under these conditions? We are employed and do not always have the opportunity to ventilate additionally at midday. We would of course prefer to invest the money for the ventilation system, which was not offered/discussed, into the list of special requests.

A thermal insulation certificate with details of our house type and even the house number, according to the Energy Saving Ordinance 2009 (KfW 70 standard) and energy certificate, is included in the building description, and the values are difficult for me to understand. Energy certificate information ("free ventilation"), valid until 2021, is included.

Can anyone help or share their opinion on this?

We look forward to your response in advance

Heiko and Martina

My opinion: building a house nowadays without [Kontrollierte-Wohnraumlüftung] is grossly negligent and a false economy. But you can read plenty about that here in the forum. At bosy-online, there is more to read about it.

Hello ypg,

Thanks for your opinion. While browsing I found a much-discussed topic :cool:. I think most people would buy a controlled residential ventilation system as a precaution, but like most, would rather invest the money in "visible" extra costs :o

Since the bungalow with 88m² living space is not very large and consists of only 2 rooms + utility room and bathroom, maybe the installation of 2 pieces (?) Viessmann Vivovent 200-d could be a cost-reducing alternative? The living kitchen is about 45m².

Possibly also in combination with window folding ventilators (?). What do you think about that?

Thanks in advance

Heiko

Attached is the proposed allocation

So window slot ventilators are the most ridiculous invention of all time... I build a window as airtight as possible with God knows what U-value... spend tons of money to make sure it's airtight and then let holes be cut into the rubber seal or into the frame???

So something must be wrong with the logic, right?

You need:

Utility room: exhaust air
Bathroom: exhaust air
Kitchen: exhaust air

Living room: supply air
Bedroom: supply air

So at least 5 units,

you have to calculate what is cheaper... since you only have 88 sqm you don't need a huge system either, a compact central unit with 180 cubic meters would be enough.

...since you only have 88 sqm, you don't need a huge system either; a compact central unit with 180 cbm would be sufficient.

Thanks for the tip.

We also have a walkable attic accessible via retractable ladder in the order. If we place the system on the floor and drill a hole in each ceiling, we could easily clean the unit, since the pipes "lie around" on the floor.

Or maybe that's not allowed (attic receives insulation between rafters):confused:? Or does such a ventilation system still require a water supply/drain :confused:

Thanks in advance:)
Heiko