Financing house construction offer 138 sqm single-family house 2 full floors + basement

Hello to all homebuilders,

my wife (29) and I (28) are planning to build our own home next year. Therefore, I would like to describe our construction project here and gather your expert knowledge on our ideas, plans, and a present offer.

Current situation:
We have inherited a plot within the Frankfurt a.M. metropolitan area (approx. 420 sqm, see land register extract). The plot is currently still built on. Year of construction approx. 1929 and not to be renovated, fully basemented.

Our plan:
Demolition of the old house and new construction. The old house is almost on the border with the neighbor and directly on the sidewalk. The new house must no longer be on the border with the neighbor but must be set back. Building on the sidewalk would be possible but is currently not desired by us for cost reasons (sidewalk support) and floor plan planning. Therefore, the house will be set back 3-4 m to the west and 1-2 m to the south.
Planned is a house with approx. 135-140 sqm living space and full basement (usable cellar).

Development plan/restrictions
Plot size - 420 sqm, see land register extract
Slope - none
Site occupancy index
Floor area ratio
Building window, building line and boundary
Edge development – development along the street permitted, not on the neighbor’s border like the current old building
Number of parking spaces
Number of floors
Roof shape
Style
Orientation
Maximum heights/limitations
Other requirements – development according to §34 (there is almost everything built in the neighborhood, so many things are permitted)

Builders’ requirements
Style, roof shape, building type – modern detached house, gable or hipped roof
Basement, floors – full basement, 2 floors
Number of persons, age – 2 (m, 28; f, 29), planned 2 children
Space needs on ground floor, upper floor – approx. 140 sqm
Office: family use or home office? – office absolutely necessary
Overnight guests per year – 2 persons several times a year (family and friends visiting)
Open or closed architecture – open
Conservative or modern construction – modern
Open kitchen, cooking island – separate kitchen with large sliding door to dining area
Number of dining seats – 6
Fireplace – no
Music/stereo wall – no
Balcony, roof terrace – no
Garage, carport – prefabricated garage 3x6m or 3x9m
Utility garden, greenhouse – small utility bed
Other wishes/special features/daily routine, also reasons why this or that should or should not be – orientation to south and west, as there is sun and few neighboring houses there, build close to the street to have more garden but not directly on the street to avoid sidewalk support during basement construction

House design
From whom is the planning – planner of a construction company
What do you particularly like? Why? – design almost completely according to our ideas, combines all our specifications, we especially like the arrangement in the bathroom
What do you not like? Why? – kitchen still needs to be closed off – distance in the living area between south wall (to the garden) and inner wall (to the stairs) might be a bit too small (approx. 4 m) to place a sofa and a wall unit there. We still have to look at this in a show house or similar to see if the space is sufficient – office possibly to be reduced by 50 cm to create space for a built-in closet (shoes, jackets, etc.) – distance bathtub - washbasin possibly too small. We also have to look at this in person.
Price estimate according to architect/planner: 355,000 (offer available)
Personal price limit for the house, including equipment: 500,000 (including incidental construction costs)
Preferred heating technology: air-water heat pump

If you have to do without, on which details/extensions
-can you do without: finishing of the basement, KFW 55
-can you not do without: basement, office

Why did the design become what it is now? E.g.
Standard design from the planner? – design created in consultation with us (from the initial discussion). Details still need to be revised
Corresponding/which wishes were implemented by the architect? – see above

Offer
Inclusive services from the construction service description and the offer:
- 88 sqm base area, approx. 138 sqm living area
- 2 full floors and full basement
- hipped roof
- building application, execution planning, static calculation, energy-saving ordinance certificate, construction management
- construction toilet, scaffolding, disposal of waste and construction rubble, construction site setup
- rough ceiling height ground floor 2.645 m, upper floor 2.77 m
- cement-lime plaster and topcoat plaster - approx. 5 cm screed
- thermal and impact sound insulation under screed
- edge insulation strip in the wall area remains uncut
Basement:
- excavation, backfilling, and compaction
- 1 basement window per room 88.5 x 76 cm including plastic light well and galvanized grille cover
- base plaster (sealing plaster M3) and coating
- horizontal and vertical sealing
- wall protection panels
- utility room including all connections
- connection lines to ground floor/attic
- electrical meter cabinet
- rough ceiling height 2.375 m
- interior finishing basement: underfloor heating, interior plaster, screed including insulation, electrical installation, window sills, interior doors
Energy:
- air-water heat pump Daikin Ultra R-32 Bluevolution
- underfloor heating with individual room control
- blower door test
- aerated concrete (30cm), monolithic
- interior walls also made of aerated concrete
Interior plaster
- machine gypsum plaster Q2 (extra charge Q3 5€ / sqm)
- ceiling joints will be filled
Bathrooms:
- shower bathroom on ground floor (floor-level shower)
- full bathroom (floor-level shower and bathtub)
Windows and doors:
- aluminum front door (company Rodenberg), with and without glazing
- 8x electric shutters, others with strap (extra charge for electric shutters 437 € / piece)
- windows with RC1 fitting - 28 sqm window area
- windows outside anthracite, inside white
- company Rehau
- exterior window sill granite
- interior window sill marble
- interior doors CPL coated, hollow chipboard
- triple-glazed windows (also in basement)

Stairs:
- solid wood staircase including railing or raw concrete staircase including storage room in the basement but without railing, handrail, and final covering
Roof:
- purlin roof made of KVH - insulated with floor insert ladder
- conduit for photovoltaic system to utility room
- roof overhangs with profiled wooden boards and painted in desired color
- approx. 30 cm roof overhang, concrete roof tiles, Braas, Harz tray
- vapor-permeable underlay
- gutters and downpipes made of titanium zinc
- mineral wool insulation
- gypsum board cladding
Electrical:
- meter box with meter field
- distributor
- circuit breakers
- Busch and Jäger / Gira
- approx. 40 sockets included (extra charge settled directly with electrician approx. 45 € / piece)
- doorbell
- 1x telephone, 1x antenna
Sanitary:
- cold and hot water pipes with VPE pipes
- pressure reducer - backflushing fine filter
- garden water connection - company Vigour (Clivia and One)
- washbasin, sink, mixer tap, toilet, built-in tub, shower tray
Optional additional services:
- KFW 55 house: more insulation at the floor slab and roof, exterior wall 36.5 instead of 30 cm (additional costs 15,800 €)
- WU basement 19,343 €
- per sqm window area 793 €
- if the basement is not finished, cost reduction of 14,000 €
Not included:
- tiling work (material and labor)
- cost estimate 8,000 €
- floor coverings - cost estimate 6,000 € (installed by own work)
- painter - cost estimate 3,000 € (material only)
- carport/garage - cost estimate 10,000 € (prefab garage or carport)
- outdoor facilities - cost estimate 5,000 € (lots of own work, will be done gradually)
- demolition - cost estimate 40,000 € (very generously estimated, more likely 25-30,000 €)
- sample selection - cost estimate 10,000 € (provider’s experience value)
- entrance platform and canopy
- kitchen
- excavation pit securing
- additional sockets
- miscellaneous - ???
Incidental construction costs:
- total cost estimate by provider of 40,000 € - building permit and static check (if required)
- final surveying, rough staking, fine staking
- sewer trench, inspection shaft
- sewer, water, electricity, telephone connection
- leveling
- cistern (if required)
- insurances
- construction electricity and water
- soil removal and disposal (since a basement pit is already present, this item will probably not be as large as usual)
- soil survey
- notary and land registry entry

Summary of costs:
- land 0 €
- house price 355,000 €
- demolition 40,000 €
- incidental construction costs 40,000 €
- other 42,000 €
- total costs approx. 477,000 € - budget 475,000 - 495,000 €

Further considerations:
- take the KFW option, as the subsidy covers the extra costs. However, this depends on our bank’s loan conditions, whether it is worthwhile, as the KFW only has a fixed interest rate for 10 years
- total costs feasible, but no additional buffer. Buffer already generously included in demolition and incidental construction costs. We still need to obtain a cost estimate for the demolition to assess this more accurately

We look forward to your opinions and suggestions!
- What would you change in the floor plan
- Is the cost estimate realistic in your experience?
- What points are still missing?
- Have I forgotten important cost items?
- What else have you noticed?

Best regards!

For your calculation, I would see significant surcharges in the following areas:

Outdoor facilities: 5k is practically nothing. No matter how much EL you provide. That is barely some gravel, curbstones, and cement for splash protection. I would set at least 20k there and then also enhance it with a lot of EL.

Electrical: 40 sockets for the entire house including the basement? Then calculate about 50-60 more. How many LAN connections are included in the price? The same applies to toggle switches, ceiling outlets, spot (preparation) in the ceiling. Have all the prices named to you in advance. So that you are not tied to the electrician of the general contractor afterwards and he charges exorbitant prices.

What does the sanitary equipment look like? How much budget is calculated in the standard package? Just listing the items does not help you. If it’s the simplest standard, that might be about 3k. Once you have been to a bathroom studio, you will quickly realize how expensive these items are. For example, is there a specified standard brand and model for the toilet? We knew that amount X was included in the package and everything else was charged additionally. This amount X is important to know how high-quality the standard equipment is. Alone for this point, additional costs of up to 10k (depending on the inclusive standard of the GC) are quickly spent.

Stairs, that will be a standard stairway. Custom designs in this area get expensive quickly. I would calculate with a raw concrete stairway from the GC and find out what your desired covering including installation would cost extra. That would be the minimum reserve I would additionally calculate here.

Doors: I find nothing concrete on that. What budget does the GC calculate per interior door? What are the costs included as standard for the exterior door? These are potentially also points for upgrades that should be clarified in advance.

Additional construction costs: I would budget for an expert.

I have no knowledge about the demolition. Does the old house also have a basement? Do you have to partially fill it? It is only partially built over with the new plan and must still be extended on the other side? I imagine that to be quite elaborate.

Excavation, backfilling, compaction: Is really all excavation included there? Without a prior soil survey, does the GC agree to that? Also possibly disposal costs. Or where do you want to take the basement excavation from the small plot? In case of doubt, depending on quality, it is not suitable for backfilling the pit either. This position is often the wildcard in construction. There are few GCs who offer everything inclusive in this area since the cost risk is also very high.

The floor plan is difficult to assess with the few dimensions. Draw in your desired furnishings. Why do you have a higher ceiling in the upper floor than in the ground floor? Normally, it is the other way around.
At first glance, the small cloakroom, the single-leaf door to the living room, the impractical layout of the kitchen for me, the small terrace doors in the living/dining area, only one shower in the house, and the trapped dressing room would bother me. But that can be better assessed with more dimensions. The upper bathroom could also get a bit tight with T (but again depends on the dimensions).
Overall, it still seems to me to be a very "rough" development stage.

Approx. 40 sockets included (additional cost is settled directly with the electrician approx. €45 / piece)

Count on at least €5000 extra... besides the 40 sockets, quite a few are still missing, then some outdoor lighting, outdoor power, two-way switches, LAN, etc.

Sample selection - cost estimate €10,000 (provider's experience value)
- Entrance platform and roof
- Kitchen
- Excavation pit securing
- Additional sockets
- Miscellaneous - ???

I find the calculation outdated - reminds me of our numbers from 7 years ago. Today it is more expensive. Outdoor facilities: 5000 for the non-visible, 10000 for visible ground material, 10000 labor cost. Plus greenery, plus fence...
A lot about construction costs is in our construction cost subforum!

Thank you for your quick and detailed reply, Crossy!

Outdoor facilities: 5k is practically nothing. No matter how much EL you provide. That’s just a bit of gravel, curbstones, and cement for splash protection. I would at least budget 20k for that and then enhance it with a lot of EL.

We will inform ourselves more precisely there and increase the capital accordingly.

Electrical: 40 sockets for the entire house including the basement? Then calculate about 50-60 more. How many LAN connections are included in the price? Same for two-way switches, ceiling outlets, spot (preparation) in the ceiling. Have all prices named in advance. You don’t want to be bound to the electrician of the general contractor afterwards and have them charge astronomical prices.

Yes, sockets are definitely too few. We are also calculating with 100 sockets. I forgot to list them. Price per unit about 30€. We will get the other prices provided.

What does the sanitary equipment look like? How much budget is calculated in the standard package? Just listing the articles won’t help you. If that is the simplest standard, that might be about 3k. Once you have been to a bathroom studio, you will quickly realize how expensive these items are. Is there, for example, a specified standard brand and model for the toilet? We knew that amount X was included in the package and everything else was added on. This amount X is important to know how high-quality the standard equipment is. Just for this point, you can quickly spend an additional 10k (depending on the inclusive standard of the general contractor).

What does the sanitary equipment look like? How much budget is calculated in the standard package? Just listing the articles won’t help you. If that is the simplest standard, that might be about 3k. Once you have been to a bathroom studio, you will quickly realize how expensive these items are. Is there, for example, a specified standard brand and model for the toilet? We knew that amount X was included in the package and everything else was added on. This amount X is important to know how high-quality the standard equipment is. Just for this point, you can quickly spend an additional 10k (depending on the inclusive standard of the general contractor).

Staircase will be a standard staircase. Customizations in this area get expensive quickly. I would budget for a raw concrete staircase from the general contractor and find out what your desired covering including installation would cost additionally. That would be the minimum reserve I would additionally calculate.

That’s good to know. We will also have the exact list provided here. For the staircase, we thought the same but haven’t researched anything concrete yet.

I don’t know much about demolition. Does the old house also have a basement? Do you have to partially fill it? It will only be partially built over with the new plan and on the other side still extended? I imagine that is quite elaborate.

As said, we have to wait for the offer from the demolition company.

Why do you have higher ceilings in the upper floor than in the ground floor? Normally it’s the other way around.

Honestly, I don’t know :D

Excavation, backfilling, compaction: Is the entire excavation really included? Without a prior soil survey, does the general contractor agree to that? Also possible disposal costs. Or where do you want to put the basement excavation with the small plot? Depending on the quality, it is often not suitable for backfilling the excavation pit. This item is often a surprise expense in construction. There are few general contractors who offer everything included in this area because the cost risk is very high.

The disposal costs are not included. How exactly it is with the excavation, can probably only be said once a survey is available.

Thanks for your comments!

So far, unfortunately, a lot is still up in the air. Still surprising that we probably won’t get our house for 500,000€, even though there are no land costs. Is our project generally that expensive?

- House price €355,000

What exactly is included now? House with basement without tiles, painting, and flooring? WU basement, KfW55, etc. all on top? For 140 sqm that would be quite cheap, that's €2,500/sqm including basement

Still amazing that we probably won't manage with €500,000 for our house, although no land costs apply. Is our project generally that expensive?

No, not amazing, yes, that expensive. We are planning something smaller and without a basement, but (excluding land) we don't get much below €500,000.

Your project is not particularly expensive. Building in general is simply expensive. And your construction including the basement is not exactly small.

The standard calculation would be:

Living area ground floor/upper floor 140 sqm * 2250 EUR -> 315k
Basement as utility basement 70 sqm -> 80k (probably somewhat more, and if you want actual living space I would also calculate with 2250 EUR/m2)
Demolition: ?
Earthworks including disposal: 25k (+/- 10k depending on disposal costs and how much excavation you actually save by using the old basement pit)
Other incidental construction costs: 30k
Outdoor facilities: 20k (personally, I would set 30k myself with [EL], terrace roofing or smaller slope reinforcements are not included in the budget)
Carport/Garage: 10-25k depending on wishes (additional room?, single parking space? ...)
Kitchen: 20k
Miscellaneous (furniture, lamps ....): 10k - xxk

So including demolition I would calculate over 500k. Extras come on top (e.g. fireplace, photovoltaics, air conditioning, and another 1000 nice little things for which you can spend a lot of money but don’t have to) as well as additional costs if the basement is desired in living quality.

The FFM moving-in area is not the cheapest spot in the republic either. With the inherited plot, you basically hit the jackpot.