Controlled residential ventilation with heat recovery is not a must..??! Please help

I have now looked around for hours and am still at the beginning! But I'll start from the beginning: We are planning a new build, 155 sqm, Kfw 70, air-water heat pump and fireplace for the cold days. 4 people...(anything missing)

So far, we always thought that ventilation was a MUST. We got some offers and ventilation was always included. Our newest architect (one who finally convinced us!) proposed a controlled residential ventilation system with heat recovery in his calculation. But he made it very clear, NOT A MUST! If you ventilate properly. Costs: €10,000! We heard that for the first time...(embarrassed)

For us, €10,000 is a lot of money! We have not been good ventilators/residents so far, especially in winter. But we never had mold (probably because of the 100-year-old house).

Can someone help us or give tips on how to get to the right result. Who helps with such questions...energy consultant?

Are there other systems/ventilation types that are cheaper and still make sense?

Many thanks!

Hello,

We are planning a new building, 155 sqm, KfW 70, air-to-water heat pump and fireplace for the cold days. 4 people... (anything missing)
... Our newest architect (one who finally convinced us!), in his calculation, suggested a controlled residential ventilation system with heat recovery. But he made it very clear, NOT A MUST! If you ventilate properly. Cost: €10,000! That was the first time we heard that... (embarrassed)

A controlled residential ventilation system with heat recovery is not a must, that is correct; whether it is wise to save on it, is a completely different question!

You are building KfW 70 - I only know a few architects who plan monolithically, so yours will have planned an ETICS. Now it is so that the valid Energy Saving Ordinance - to put it simply for laymen - requires that in the end you get a "thermos flask." So if an ETICS is actually installed and you cannot - if you and your wife both work - ventilate properly (at least 4 times a day for a good 10 minutes), a controlled residential ventilation system remains a good recommendation. Maybe that’s why the other providers offered this system?

€10,000 is a lot of money for us! We have not been good ventilators/residents so far, especially in winter. But we never had mold (probably because of the 100-year-old house).

That is a lot of money for everyone! If you read up a bit here in the forum, you will find that quite a few builders no longer want to do without a installed controlled residential ventilation system with heat recovery.

Can someone help us or give tips on how to reach the right result? Who helps with such questions... energy consultant?

€uro will confirm - I am not quite so optimistic because many so-called energy consultants are likely to be called into question and I have already had to endure some specimens that I would have loved to kick in the backside. Very few have much real knowledge themselves and recommend such nonsense to their clients that makes me nauseous.

For example, find a suitable expert through the Association of Independent Experts who states in their biography that they have learned energy consulting and not just attended a questionable seminar. Otherwise, call me if you get stuck.

Are there other systems/ventilation types that are cheaper and still make sense?

I think your architect is that good? Didn’t he advise you, at least - if it’s down to the money - to consider a decentralized system? Or do you only find him good because he apparently saves you €10,000?

It is currently a real dilemma - neither salespeople nor architects are able to sell prices, it must be really difficult to advise with arguments/facts.

Kind regards

You are building KfW 70 - I only know a few architects who plan monolithically, so yours will also have a ETICS planned. Now, the valid Energy Saving Ordinance - put simply - requires that, in the end, a "thermos flask" is achieved. So if indeed an ETICS is installed and you cannot ventilate properly (at least 4 times a day for a good 10 minutes) - provided that you and your wife are working - a controlled residential ventilation system remains a good recommendation.

Do you see such big differences regarding controlled residential ventilation between an ETICS and a monolithic wall structure?

Both should be "airtight"... right?

You are building KfW 70 – I only know a few architects who plan monolithically, so yours will also have planned an ETICS. Now it is such that the valid Energy Saving Ordinance – expressed in layman’s terms – requires that in the end a "thermos flask" is achieved. So if an ETICS is actually installed and you cannot ventilate properly (at least 4 times a day for a good 10 minutes) – assuming your wife and you are working – a controlled residential ventilation system remains a good recommendation. Maybe the other providers offered this system for that reason?

=>All providers have offered a system, only it was previously "included" or sold together with the heat pump. What does ETICS mean? It is still unclear to me who is at home all day and can ventilate to that extent, so I have been in favor of controlled residential ventilation up to now.

That is a lot of money for anyone! If you read a little in this forum, you will realize that quite a few builders no longer want to do without an installed controlled residential ventilation system with heat recovery.

=>True!

€uro will agree again – I’m not quite so optimistic because many who call themselves energy consultants probably should not be, and I have already had to endure some specimens that I would have liked to kick in the behind. Very few have hardly any idea themselves and recommend such nonsense to their clients that makes me feel sick.

=>I have noticed that too, hence the uncertainty.

For example, find a suitable expert through the Association of Independent Experts who also states in their biography that they have learned energy consulting and have not just attended a questionable seminar. Otherwise call me if you don’t get any further.

I think your architect is that good? Didn’t he at least advise you to consider a decentralized system if it fails due to money? Or do you only think he is good because apparently he saves you EUR 10,000?

=>We have only had two conversations with him so far. We are still at the beginning and I want to prepare for the next conversation. We like him because he has drawn a great house, the costs seem transparent, and we like him as a person. The rest will show! Most providers failed after the second meeting. The saving of 10,000 is a good approach; maybe he told us that to keep the price?

It is currently a real dilemma – neither salespeople nor architects are able to sell prices ..... it must be really hard to advise with arguments/facts.

=>For me, they are all salespeople ... I can’t stand this type of people and avoid them. Our current man really doesn’t seem to be like that ... but the “saving” again unsettles me.

Best regards

My name is Laie!...and what is a monolithic construction method. I also don't know what WDVS is. Maybe just quote from the services on this stele:

"...Exterior masonry as a plaster facade with a "thermal system," with thermal insulation, textured plaster ......Inner shell of the exterior masonry made of 17.5 cm high-insulating aerated concrete masonry (Ytong)..."

Furthermore, we talked about it again, we have been "getting to know each other" so far. At the next appointment, we can clarify questions...

Hello,

=> All providers offered a system, it just used to be "included" or sold together with the heat pump. What does WDVS mean? It is still unclear to me who is home all day and can ventilate to that extent, so far I am also in favor of controlled indoor ventilation.

WDVS => Thermal Insulation Composite System

We like him because he designed a great house, the costs seem transparent ...

What does his initial rough calculation show?

=> For me, all salespeople are - I can't stand these kinds of people and avoid them.

I am a salesperson too - with heart, body, and soul

My name is Laie!...

Maybe a program, definitely not the name or you are posting under a fake account?

"...Exterior masonry as a plaster facade with 'thermal system', with thermal insulation, textured plaster, inner shell of the exterior masonry made of 17.5 cm highly insulating aerated concrete masonry (Ytong)."

So with WDVS.

Kind regards