Assessment of ancillary construction costs - prefabricated house, without basement

Dear forum,

We find it very difficult to estimate the ancillary building costs. Maybe you could share your experiences.

The plot is being gifted to us. The notary fees are covered by the donor.

The plot is flat and located in the middle of a built-up area, at the corner of two streets. The development has been paid for, but the connections from the street to the house still need to be laid. That is on top of the costs.

We are building on a slab. The slab is already included in the house price, but we have to prepare the "pit" for the slab.

The architect fees are fixed at 5,000€.

Currently, we are budgeting 50,000€. Simply because financiers and house builders have always mentioned this as a generous calculation basis with plenty of leeway.

Nevertheless, we would be interested in your assessment.

We know that such a remote assessment is difficult – if you need more information, just write.

As a rule of thumb, 10%. You probably can't go too wrong with €50,000 at first, tendency (without missing information) rather slightly too high.

Gift of the property: what value? Maybe the tax office still wants to get its hands on it.

€5,000 is little for an architect. Are you sure everything is included, including supervision of the construction site?

Do you already have a geotechnical report? That is probably the biggest cost driver: unusable soil / contaminated soil etc. Landfills are expensive.

Good for you: flat = little earthworks Short distances for connections to the street

Problem: existing building on the corner: where to put the crane etc.?

Does incidental costs mean kitchen, garden landscaping etc. for you as well?

Dear forum,

We find it very difficult to estimate the incidental construction costs. Maybe you could share your experiences.

The plot of land is gifted to us. The notary costs are covered by the donor.

The plot is flat and located in the middle of a built-up area, at the corner of two streets. The development has been paid for, but the connections from the street to the house still need to be installed. That is additional.

We are building on a slab foundation. The slab is already included in the house price, but we have to prepare the “pit” for the slab ourselves.

The architect costs are fixed at €5,000.

Currently, we are calculating with €50,000. Simply because financiers and house builders have always named this as a generous calculation basis with plenty of leeway.

Nevertheless, we would be interested in how you assess this.

We know that such a remote assessment is difficult - if you need more info, just write.

The decisive factor in the costs is the soil report. If it turns out badly, it can already cost several tens of thousands of euros more.

Things like:
- Connections (you can ask yourself)
- Insurances (construction all-risk, builder’s liability, residential building (then you get the shell for free)) we pay about €1,500
- Land register entry, in case of financing, cost us about €2,500
- Construction access road, construction power, construction water -> think about €5,000-7,000
- Building permit costs us about €1,750

Long story short. You’re fine with €50,000 if the soil report is not catastrophic.

40k-50k is read here more often, I think there is also a topic somewhere where experiences are listed. You have picked a good benchmark.

Hi, we are also planning a prefabricated house on a slab (9.5m x 11m) and are also budgeting 50k for ancillary construction costs. Also a flat plot of land. Several companies we spoke with informed us that the amount fits quite well, with a tendency towards slightly less.

Basically, one should first of all write down the incidental building costs that arise. These include - house connection costs, which can be requested from your utility providers. Water, electricity, possibly telecom, possibly gas, etc. - construction electricity and water - incidental costs of the site container, e.g. portable toilet, container, etc. - interest on the loan during the construction period - surveyor - permits - earthworks, i.e. stability, possibly soil replacement or higher foundation costs. For this, a soil survey is required, which should be commissioned sooner rather than later - rainwater infiltration What is then added, especially for corner plots, is the fencing as well as the splash protection around the house, as well as the paving. With such a catalog, you can work, i.e. make calls, ask the architect, etc. The prefab house company is also obliged in this regard! Is this Danwood? It reads like that. Transport costs and crane are counted as house costs, right?