Two-family house new construction - Which costs to calculate?

Let two or three real estate agents take a look and evaluate the house for the market. Possibly some homestaging might still be necessary before the sale.
A real estate agent can also tell you something about the chances of sale.
We worked with an agent for half a year and eventually terminated the contract. Nevertheless, the insights gained from it helped us and brought not only the desired buyer (which was very important to us because we are now immediate neighbors) but also a significantly higher return.

For you, a multi-generational house might also be an option. There are very nice layouts in these houses.

Hello,

I have looked into it a bit more, and in our town, plots are currently being sold in an undeveloped new development area. For around 900m², you pay 77,000€ for the plot and about 42,000€ development costs. That would put me above the planned 100,000€, but not too far over with 120,000€ – I don’t think we will find anything much cheaper in such a great location.

Is there any way to save on the development costs? Either through doing some of it yourself or by privately hiring a company you know?

What would you advise? To have it built turnkey? Or have the shell construction done by a large company and organize the interior work myself? My father and I have very good contacts with tradespeople (roofers, electricians, heating engineers, floor layers, window fitters), and we believe that we could save quite a bit of money if we organized these areas ourselves. On the other hand, many people advise me against it because there will always be problems with the warranty since nobody feels responsible if something is wrong. These people advise me to build turnkey so that you have the architect as a contact person for everything that is not right. Which way do you lean here?

To come back to the KfW subsidy: What do you advise me here? I assume that if I build new and want the best KfW funding, I have to invest significantly more, which then pays off over x years, or am I mistaken?

We also considered yesterday that the new house could definitely be a single-family house with a granny flat. Is it “cheaper” then? What do you think, how much will the whole thing cost me?

I have found different figures on the Internet. Some say you should calculate about 1500€ per square meter. Others go up to 2500€. Others again calculate everything by cubic meters of enclosed space. What are your experiences here? If I take the average, so 2000€/m², I would come to 400,000€ costs for 200m² – is the plot already included in this price per m², or is it extra? 2000€/m² sounds somewhat high to me if not really everything is included (so also the plot). What do you think one should calculate with? Or are there better calculators that don’t rely on such general figures?

I thought I’d consider how the house COULD look and then at least calculate the individual rooms for the costs I assume. That works quite well because I already have a bit of experience through remodeling the old house here. But only with the interior work. How do I roughly calculate the costs for the shell construction?

Best regards,
Dirk

I'm feeling the same right now, also calculating how the construction costs are made up.

But I believe: Whether €1500/m² or €2500/m², the land costs are not included in that.
I am in the preliminary planning with our architect. It is supposed to be a house with a basement apartment.

In a first cost estimate we are at

about €1525/m² living space excluding ancillary costs or €1956/m² living space including all ancillary costs.

Since land prices can vary enormously, it is also difficult to include them in this calculation independent of location.

Hello Dirk,

I estimate building plots based on various real estate portals at €100,000 for about 800m² here in town – fully developed, mind you.

For a two-family house, I then calculate €400,000. About 100m2 are to be built for my parents (ground floor, no stairs) and 150m2 for us (preferably 1.5 floors) plus or minus, of course. Probably no basement. 2-3 garages. Underfloor heating,

In the following example, the utility room is located on the ground floor; thus, reducing the floor space for the parents. Floors: ground floor, first floor + attic

Plot: €100,000
Two-family house according to the Energy Saving Ordinance and on BP: €356,000
Painting work/floor coverings in EL: €20,000
Outdoor facilities in EL: €10,000 (only the essentials)
Reserves extras: €15,000
Additional construction costs: €40,000
2 prefabricated garages 3 x 9 including sectional door and strip foundations: €22,000

All in estimated €563,000.

Of course, depending on the budget, but especially on the available building window, there is also the possibility to realize the residential units (WE) side by side. So the apartment for the parents as an extension and the residential unit for you classically on the ground and first floors. Then the base price for the two-family house is €411,000.

Is there any way to save on development costs? Either through own work or through privately commissioning a company you know?

Only for the internal development.

The external development includes the public utilities in the street in front of the plot (sometimes they are extended about 1.00 m into the plot) such as the planned street, which - after completion of all construction work - receives a final surface. These services are tendered by the municipalities and then - for smaller construction projects - awarded to a single developer. EL is not desired here.

My father and I have very good contacts with craftsmen (roofers, electricians, heating engineers, floor layers, window makers) and we believe that we can save a lot of money if we organize these topics ourselves. On the other hand, many people advise me against it because there will always be problems with the warranty, as no one feels responsible if something is wrong. These people advise me to build turnkey; then you would have the architect as a contact person for everything that doesn’t fit. What is your tendency here?

You will not come out cheaper; perhaps somewhat higher quality in the installed materials. At the end of the day, the invested sum will be the same.

You should only consider such an undertaking if you have more than rudimentary knowledge of what you intend to do. Your father is – naturally – already older and experienced in life, but unfortunately his knowledge of the trades – where present – is limited as well. External supervision is also recommended with this choice because someone with expertise must approve the individual trades. Then any warranty claims will also work out.

We also considered yesterday that the new house could definitely be a single-family house with a granny flat. Would that be "cheaper"?

Why should it be? The space requirement remains the same.

I found different figures on the internet.

Which should be treated with caution because they were calculated by software.

Rhineland regards

Hello building expert!

... and thank you very much for your effort!

So with all-in 563,000€ I think I could manage. With the 411,000€ base price, one presumably replaces the 356,000€ above, right? And that comes to 608,000€ total costs? From this I conclude that "building outwards" is about 10-15% more expensive than "building upwards"?

Assuming I would get 285,000€ for the old house, from which the loans are paid off. That would leave about 75,000€ equity, which would be about 12% of the 600,000€. Actually too little if you take the recommended 25-30% as a guideline. Loan installments for a 525,000€ loan with 2% interest and 2% repayment would then be about 1900€ monthly.

Does the calculation example you mentioned qualify for a KfW subsidy? Or does one have to add an amount X on top of that?

Hello,

... and thank you very much for your effort!

You're welcome.

With the base price of €411,000 you presumably replace the €356,000 above, right?

Yes.

And that results in total costs of €608,000?

TEUR 618

From this I conclude that "building wider" is about 10-15% more expensive than "building upwards"?

Building wider means a larger foundation slab and consequently a larger roof area. This can hardly or not at all be expressed in percentages, because the architecture that rises also always plays a significant role.

Does the calculation example you mentioned qualify for KfW funding? Or do you have to add an amount X on top?

No, I wrote "according to the Energy Saving Ordinance". As of today, a KfW 70 efficiency house with an air-water heat pump, from January standard Energy Saving Ordinance (where KfW 70 Energy Saving Ordinance 2014 results in a bit more than standard Energy Saving Ordinance 2016). Since no building application needs to be submitted in the remaining period until the end of 2015, I simply wrote Energy Saving Ordinance. Sorry if I expressed myself unclearly.

If you want to build the calculation example according to KfW 55, you will certainly face additional costs of a good TEUR 17 - 22. For a different brick, more insulation under the foundation slab/in the rafters, a controlled residential ventilation with heat recovery (decentralized from TEUR 9) and expert support.

Rhineland regards