Cost estimation for construction project and feasibility

Hello everyone,

we are currently considering building a house. Due to the high prices for used properties, only a new build is really an option, as I would prefer to pay the 10-15% more and realize my personal vision. Fortunately, there are several new development areas. The plots that are suitable for us are priced at around €150,000 for 600-700 sqm.

We imagine a detached single-family house with 150 sqm of living space, 1.5 floors with a double garage. A basement is not an option. The quality should be average; we have no huge demands. This leads me to the following cost blocks:

Plot including all costs (real estate transfer tax + notary, fully developed): €160,000
Construction costs: 150 sqm * €1800/sqm = €270,000
Double garage, masonry with direct access to the house: €25,000
(additional) costs (kitchen, garden, furniture, etc.): €30,000

This totals €485,000. Currently, equity of €125,000 is available, possibly there will be a subsidy from family, but we do not want to plan with it for now. Thus, a credit amount of a solid €360,000 remains. Of course, I have played a bit with the construction financing calculators: 1.5% interest, 3% repayment, 15 years fixed interest => monthly rate €1350. The residual debt of €180,000 after the end of the fixed interest term I consider uncritical. As a buffer, I see the possibility of personal contribution (flooring, painting, garden), which I would estimate at €10,000.

Regarding our situation: Both 29 years old, married, 2 children (1 and 3), single earner in a large corporation, IT field. Including child benefit, we have a net minimum of €4,300 per month, the realistic income is €4,800 (this includes contractually guaranteed bonuses, holiday pay, overtime, etc.). My wife will certainly take a job on a €450 basis at some point, and my salary will almost automatically still be able to increase somewhat. We are completely debt-free, both cars belong to us (2.5 & 4.5 years old).

Of course, I have no experience in house building or financing. Therefore, I would appreciate an assessment regarding the costs we have planned and an evaluation of the financing project. Personally, I am a bit hesitant about the high sum, but basically I see no massive restrictions in life with the rate.

Thank you very much for your answers!

How did you determine the numbers? Are there offers available? For your pure calculation, all of this is too tightly calculated. Incidental construction costs are also something different from kitchen, garden, and furniture. Financially it seems to fit, but there is easily a shortfall of 80k€ - 100k€ overall in the calculation. You urgently need to deal more with the basics of building.

From memory our additional and miscellaneous costs 2017. Earthworks 7, connections and sewage 7, painter 5 with own labor, flooring 2 likewise, kitchen Ikea 4.8, garden landscaping 16-18, extras 15, lighting and furniture 4, fees and surveyor 2, totals around 65. And we were economical

Yep, better make it 600,000, that’s the safe bet. 500k works too, with very low demands on the standard, own work, and also giving up on outdoor facilities (which can quickly become six figures)

Construction costs: 150sqm*1800€/sqm = 270,000€
(Construction) incidental costs (kitchen, garden, furniture etc): 30,000€

The 1800 depends on where you build; it is below average or not even possible in some places. In Lower Saxony, if you do without things like electric shutters, it might still be feasible.

Your incidental construction costs are still incomplete. Just for things like wastewater, house connections, surveying, construction power etc., I would estimate about 20k€ alone. Landscape gardener for simple paving and some fencing 20k€, plants and garden house completely extra.
Kitchen and furniture depend on you.

Well, there are avoidable and unavoidable additional costs. Avoidable are roller shutters, expensive bathroom fittings, large tiles, special doors, colored windows, etc.... All of that is ultimately mimicry, wiihaben, fashion. Unavoidable are the utilities, sewage, earthworks for the foundation, garden landscaping work, the development of the property. Some people do quite a bit themselves, which certainly saves money. But you have to be able to do that and manage it in terms of time. Not everyone can pave a terrace. There are also price differences in construction methods. Timber construction seems more expensive to me than brick on brick. Ytong monolithic cheaper than Poroton with ETICS. The most expensive is clinker. A steeper roof will have studio trusses, more expensive than beam trusses in timber framing. Concrete roof tiles cheaper than clay. Windows, if you stay well within the standard grid around 1 m wide and install few floor-to-ceiling windows, you save thousands. Few corners, angles, bay windows, straight ahead. Karsten