Hello everyone,
Yesterday, my husband and I attended a building consultation with a well-known construction company.
Our plan: to build a bungalow meeting the KfW 70 standard with about 120m² (1,290 sq ft) of living space, using gas and solar energy.
The salesperson said that KfW 70 is not really worth it. The additional insulation would save approximately €85 (about $90) per year on heating costs but would cost an extra €8,000–9,000 (about $8,500–9,500) upfront. He recommended a 30cm (12 inch) external wall made of aerated concrete blocks instead, saying that this would be sufficient and no extra insulation is necessary.
Now we’re a bit confused. Is he right? Or was he just trying to present the figures in a favorable way to keep the total cost down?
Does this make sense? What approach did you take? Is extra insulation worthwhile, or can it be skipped if you have the right kind of external wall?
Looking forward to your opinions.
Yesterday, my husband and I attended a building consultation with a well-known construction company.
Our plan: to build a bungalow meeting the KfW 70 standard with about 120m² (1,290 sq ft) of living space, using gas and solar energy.
The salesperson said that KfW 70 is not really worth it. The additional insulation would save approximately €85 (about $90) per year on heating costs but would cost an extra €8,000–9,000 (about $8,500–9,500) upfront. He recommended a 30cm (12 inch) external wall made of aerated concrete blocks instead, saying that this would be sufficient and no extra insulation is necessary.
Now we’re a bit confused. Is he right? Or was he just trying to present the figures in a favorable way to keep the total cost down?
Does this make sense? What approach did you take? Is extra insulation worthwhile, or can it be skipped if you have the right kind of external wall?
Looking forward to your opinions.
Hmm, I’ll boldly respond as an amateur:
Personally, I don’t trust anyone who tries to calculate my energy consumption. It’s the same as fuel consumption in a car: every car I’ve ever bought has used about 20% more fuel per 100 km (62 miles) than the manufacturer’s specifications.
At first, I thought a house built to the 2009 Energy Saving Ordinance standard would be enough. A 15% savings doesn’t sound like much nowadays... but who knows what it will look like in 10 years? Then 15% of a bigger factor could be significant. Also, not to be underestimated: the KfW70 loan. Saving 1.5% on €50,000 (about $53,000) means €7,500 ($8,000) over 10 years already 🙂
And keep in mind: thermal insulation cannot just be easily upgraded later!
A bigger financial leap would be KfW55 or a passive house. I would consider that carefully, weighing today’s realities and my current budget.
But let’s wait for the answers from the calculation experts and professionals 🙂
Personally, I don’t trust anyone who tries to calculate my energy consumption. It’s the same as fuel consumption in a car: every car I’ve ever bought has used about 20% more fuel per 100 km (62 miles) than the manufacturer’s specifications.
At first, I thought a house built to the 2009 Energy Saving Ordinance standard would be enough. A 15% savings doesn’t sound like much nowadays... but who knows what it will look like in 10 years? Then 15% of a bigger factor could be significant. Also, not to be underestimated: the KfW70 loan. Saving 1.5% on €50,000 (about $53,000) means €7,500 ($8,000) over 10 years already 🙂
And keep in mind: thermal insulation cannot just be easily upgraded later!
A bigger financial leap would be KfW55 or a passive house. I would consider that carefully, weighing today’s realities and my current budget.
But let’s wait for the answers from the calculation experts and professionals 🙂
I don’t know anyone who doesn’t add extra insulation nowadays. Even masonry provides some insulation.
There is a trend, especially among younger people, towards passive houses, but whether that is economically viable is another question 🙄
You also have to consider resale value. I currently live in a house built in 1978, my parents also built in 1978, insulated only with air.
If it weren’t for the enormous costs of adding insulation to existing properties, I would probably have bought another older house instead of building new. It simply doesn’t pay off. I believe the future lies in technology, not just the building envelope, because eventually you reach the limit of insulation. So it’s best to wrap the house well and plan for future upgrades 🙂
There is a trend, especially among younger people, towards passive houses, but whether that is economically viable is another question 🙄
You also have to consider resale value. I currently live in a house built in 1978, my parents also built in 1978, insulated only with air.
If it weren’t for the enormous costs of adding insulation to existing properties, I would probably have bought another older house instead of building new. It simply doesn’t pay off. I believe the future lies in technology, not just the building envelope, because eventually you reach the limit of insulation. So it’s best to wrap the house well and plan for future upgrades 🙂
Yes, it is all very confusing. We also thought that building to KfW70 standard would be sufficient. He just said that it is enough to build according to the current energy saving regulations. The savings you get from KfW70 are simply not worth all the extra effort. We have already decided not to work with this construction company. KfW70 remains our goal because we belong to the younger generation and want the house to last for a long time.
Best regards
Best regards
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