Construction costs when building with architects. What does your experience say?

He can of course delegate parts of it, but certainly not to the extent that the general contractor himself directs him off the construction site - even if this is rumored to be attempted here and there.

Toppi, where in BW are you building? I also come from the area and find your land price interesting. Feel free to send a DM.

Hello,
I am currently also in the process of planning a house build. In case the building authority in Waiblingen wants/can/decides to process the application.

Last year, I dealt with prefabricated houses and solid houses.
I want to build a two-story house with a raised ground floor, a granny flat, and an expandable roof. Concrete stairs.
Commercial rentals with increased soundproofing or holiday apartments.

The prices for turnkey general contractors for the premium shell construction were between €280,000 and €400,000 for timber prefab construction, differing in wooden floors or concrete floors.

The solid house made of aerated concrete costs between €260,000 and €750,000. The inexpensive version is a refined shell, the expensive version is a worry-free package.

I decided on the inexpensive solid component. I liked the offer with the mass extraction on a VOB basis best. It involves a concrete master builder with a planner (structural engineer). This will bring the entire house, including garage and individual room forced ventilation, to about €500,000 and is individually planned by me.

I really cannot recommend my approach to anyone inexperienced. The architects’ billing is based on the fee schedule for engineers and architects. It costs about €20 in bookstores. Everything is very nicely listed there. Now negotiate the category with the architect. Also write down that everything is included: no copying, office, etc. costs.

Keep in mind that for almost everyone, specialist planners, connections, building authority, utilities, etc. come at additional cost. That often makes a lot more money again.

The prefabricated house has many advantages, especially if you only use it as a private home. The cables and pipes can be excellently laid in the installation level. But seriously. Do you believe the manufacturers that the insulation still has the tensile strength to insulate everywhere after 20 years? I have seen too many water intrusions when looking more closely at existing prefabricated houses.
A solid house is also more sluggish in heat and cold protection due to its much greater mass.

If I were to build my first house again today, then turnkey and payable via a blocked account upon move-in. House acceptance through an expert.
Garage as a prefabricated garage with a cistern underneath. The cistern has the advantage that you only need a gravel bed. The garage floor tensions the lid.

Regards from Waiblingen.

The prefabricated house has many advantages, especially if you only use it as a home. The cables and pipes can be laid very well in the installation level. But seriously. Do you believe the manufacturers that the insulation still has the tensile strength to insulate everywhere after 20 years? I have seen too many water ingress points when looking closely at existing prefabricated houses.
A solid house is also more sluggish in heat and cold protection due to its much greater mass.

Sorry, do you actually have any clue about what you’re talking about here?
For example, why would wood fiber insulation need tensile strength?
What on earth does water ingress have to do with insulation?
Which construction principle has better insulation values and thus better heat or cold protection with the same wall thickness?
I wish you lots of fun in your concrete building.

The insulation of prefabricated houses is constructed in multiple layers. In three cases, the wall structure of the offer did not correspond to the prospectively stated wall structure. In all cases, mineral wool was used in the inner insulation layers. This mineral wool provided the highest thermal resistance in the wall structure according to calculations. My question to the prefabricated house builders was: How do you secure the mineral wool against the effects of gravity over the years? The answer was: Not necessary.

We have the problem that the thermal insulation effect noticeably decreases within 10 years despite good inspection. In some cases, it even halves. We know this from records at power plants. Personally, I am a managing thermal engineer with a degree in process engineering.

The advantage of mass (solid house) is hysteresis (phase shift between energy input and effect). Since the warming is proportional to the mass and today heat protection is more in the foreground. It is better to shift the warmest point into a period when there is a large temperature difference between inside and outside. This is possible, for example, at night from 2...3 a.m. on warm nights. The house then has to live off its mass for that long. That is physics, and it is difficult to argue with it.

For those who do not know what hysteresis is, a very simple example: On June 21, we have the highest energy input from the sun to the earth and in August, it gets really hot. On December 21, we have the least sun and in February it is bitterly cold. Thus, on earth, we have a hysteresis of about two months. And it is the same in a house. I hope I will not be stoned now.

In this sense, have fun in the forum. I am logging off again.

The insulation of prefabricated houses is constructed in multiple layers. In three cases, the wall structure of the offer did not correspond to the advertised wall structure..

What is this statement supposed to tell me?

In all cases, mineral wool was used in the inner insulation layers. This mineral wool theoretically provided the highest thermal resistance in the wall structure. My question to the prefabricated house builders was: How do you keep the mineral wool in place against the long-term effect of gravity? The answer was: Not necessary.

Why should it be? If properly installed, nothing happens. If mineral wool is as unsuitable as you write, I wonder why it is also used as insulation in the roof areas of solid houses. Should there be no gravity there?

We have the problem that the thermal insulation effect significantly decreases within 10 years despite good inspection. In some cases, it is even halved. We know this from records at power plants. Personally, I am the managing thermal engineering engineer with a degree in process engineering.

Who inspected what here?

The advantage of mass (solid house) is hysteresis (phase shift between energy input and effect). Since the warming is proportional to the mass and nowadays heat protection is more in the foreground, it is better to shift the warmest point to a time when there is a large temperature difference between inside and outside. This is possible, for example, at night from 2...3 o’clock on warm nights. The house then has to live off its mass for that long. That is physics and it is difficult to negotiate with it.

Very impressive. If that is true, your solid house also has an undeniable disadvantage: It also takes much longer for a solid house heated (overheated) by solar radiation in summer to cool down again to tolerable temperatures.

For all those who do not know what hysteresis is, a very simple example: On June 21, we have the highest energy input from the sun to the earth, and it gets really hot in August. On December 21, we have the least sun, and in February it is bitterly cold. Thus, we have a hysteresis of about 2 months on earth. And it is exactly the same in a house. I hope I won’t be stoned now.

I can exceptionally agree with this statement in parts. However, it only applies to the northern hemisphere and not to the entire earth, Mr. Engineer...