New project single-family house

Hi everyone,

we are currently planning to build again and I came across this forum during my research. I would like to gather your opinions and feedback throughout our construction planning. To start with, a constructive assessment would be great to see if we are planning within a realistic price range.

The total budget for the project is 500k€ – of which about 85k€ +- 1-2k is for the plot including property transfer tax + notary fees.

This leaves approximately 420k€ for the house + additional costs. We want to build with an architect who, according to the corresponding cost calculation based on HOAI, charges about 10% of the budget as his fee (1-8), so about 380k€ remain for the pure house construction.

The following parameters are envisaged for the project:

KFW 55 house
Air exchanger with heat recovery (cross-flow heat exchanger)
Ground or air-water heat pump
Photovoltaic system + storage
Fanless pellet stove
Room height 2.60m
Double garage + storage room
Basement (habitable, height 2.20m)
Underfloor heating
Solid construction (feedback on bricks = KS, Liapor, Poroton welcome)
Clinker facing
Electric shutters
1.5 storey
Mono-pitched roof
KNX (at least prepared, i.e. star-shaped wiring, ideally including actuators but depending on cost)
Windows + doors + shutters burglary-proof
Paving of the access path (approx. 50m2)
2x bathrooms (1x including bathtub, 1x "small" bathroom for children including shower, without bathtub)

What square meter number for the living area is realistic, or which positions appear not feasible? Regarding photovoltaic + storage + heating, it should be noted that no government subsidies (KfW grants or BAFA, etc.) are included in the budget; these would come on top of the budget for heating + photovoltaic + storage.

Thanks for your feedback.

Best regards, Thomas

Better not to count on any subsidies either. It’s nice if you get them, but you can’t really rely on it. So it's better to first ask the bank how much credit you would get if there were no government subsidies at all, and then set the budget accordingly.

Apparently, you don’t have a plot of land yet. How the house is allowed to look from the outside (number of floors, permitted roof shape, regulations for the exterior façade) depends on the respective development plan. What if you now find a wonderful plot in a great location, but only hip or gable roofs are allowed there? Or if the house must be plastered yellow on the outside and the bricks are only allowed to be gray? Would you then not take the plot? Consider in advance at which points you are willing to deviate from your ideas.

Solid house (brick on brick) is classically popular, but why not a prefabricated house? Especially with energy-saving and passive houses, there are plenty of fixed-price providers who are not only certified but also already have some customer reviews. And it is built faster than a solid house. Pricewise there is little difference. Which specific advantages of solid construction are important to you? Is there a guarantee that you can also use these advantages on every plot you eventually find?

Electric shutters are nice and all, but what do you do in a power outage when you then can’t open them in the morning? Sit in the dark all day? I would rather choose manual operation, or at least want to have the option for it.

Burglar-proof windows and doors are standard nowadays and should not cost extra; if a provider tries to sell you otherwise, they are not up to date, and you should reconsider your choice of provider. Incidentally, electric shutters may be less burglar-proof than manually operated ones because the electric ones usually come with automatic control. Nowadays, they can be controlled via a smartphone app – and a burglar can also hack into that. Then they stand on the property with their smartphone, open all the shutters automatically, and easily break in by destroying the cylinder of the terrace door with a cordless drill within seconds or classically prying open a window with a crowbar. If, on the other hand, the shutters stay down because they can only be opened manually from the inside, a burglar will have a much harder time and might rather break into a neighbor’s house that has a hackable electric system...

Are you willing to do some of the work yourselves? Paving the access road is easy and a layperson can do it too. Then you would only have material and possibly delivery costs.

Why do the children get the small bathroom without a tub? Especially children always want to bathe, whereas we adults never have time and only shower quickly before rushing to work. Two bathrooms—great. One of them with a tub—also great. But adults only use a bathtub occasionally (on a relaxed weekend maybe, when the children are with the grandparents). It’s better to make both bathrooms sufficiently large, both with a toilet and sink, and the shower in the parents’ bathroom can be a bit more luxurious (e.g., floor-level, also with regard to age-appropriate living in the future). You shouldn’t skimp at the wrong place here.

Pellet heating systems are available off the shelf, installation is not complicated, and the actual radiators also need little space; but the storage for the pellets with the feed screw takes up much more. For that, you can plan for some cubic meters of space in the basement.

On the subject of basements: every living space needs its own escape route in case of fire. So if the basement is to be used as living space, each individual basement room must have such an escape-capable window to the outside. And if it is a real basement, i.e., underground, light shafts (with windows) are needed for this. Where rotting leaves and pests collect, grids or not. And where intruders can theoretically break in unnoticed. Perhaps you choose a hillside plot and only use part of the basement as living space, where you can get out into the garden from the windows in an emergency; a pantry, pellet storage, or heating/laundry room does not need a large escape window and super insulation by the surrounding earth is very welcome there, so these can be completely underground.

Having your own photovoltaic system is of course nice (if the power ever goes out, you just switch from grid feed-in to self-use and still get the shutters open), but maybe you prefer a combination with solar collectors for heat generation. Probably brings more in winter.

"Burglar-proof windows and doors are standard nowadays and should not cost extra" <- I rather think that someone who sells this as "standard" has already factored it into the price beforehand... "And it is built faster than a solid house." <- the actual construction time yes; lead times including our experience no. "There is little difference in price." <- we have had different experiences "Electric roller shutters are nice and all, but what do you do during a power outage" <- use the front door? "If anything, electric roller shutters are less burglar-proof than manually operated ones" <- says who!? I can’t control anything with an app here... "Paving the access path is simple, even an amateur can do it" <- don’t underestimate it... otherwise you won’t enjoy it much "Every living space needs its own escape route in case of fire" <- in a single-family house? That would mean that all children’s rooms would need an escape staircase... "But maybe you’d rather use a combination with solar collectors for heat generation. Probably more effective in winter." <- !? Solar thermal generally yields little anyway... Otherwise: 380 k€ for how many square meters? 380 k€ can fit - with a basement but possibly difficult.

The total costs depend heavily on your plot of land and the soil survey. The civil engineering can be in the four-digit range, or quickly reach five digits, depending on the soil and cubic meters of the basement.

If you want a residential basement, I can only recommend building it at full height, that is 2.50 meters room height from the top edge of the finished floor.

KfW or Bafa subsidies are certainly nice, but plan without them.

Do you want to plan only one residential unit or one with a granny flat?

For the budget, I would plan with about 450K - 500K euros for approximately 200 sqm of living space.

But the calculators here in the forum can surely say something more precise about that.

If you already have an architect on board, look for a plot together. Check exactly what costs are involved in your planning.

:

Hello,

You do have some interesting views... :confused:

Burglary-proof windows and doors are standard nowadays and should not cost extra; if a provider tries to sell you otherwise, they are not up to date, and you should reconsider your choice of provider. By the way, electric shutters might be less burglary-proof than manually operated ones, because the electric ones usually come with automatic controls. Recently, they can be controlled via a smartphone app – and a burglar could hack into that. They then stand on the property with their smartphone, open all shutters automatically, and enter easily by destroying the cylinder lock of the patio door with a cordless drill within a few seconds or by prying open a window with a crowbar in the traditional way. If the shutters stay down because they can only be opened manually from the inside, it is much harder for a burglar, and they might prefer to break into a neighbor who has a hackable electric system...

Burglaryproof windows and doors do not exist. However, burglary-resistant ones, in various degrees, do exist. But these are standard only with very few providers.

Electric drive or manual operation has absolutely nothing to do with a possible anti-lift device for the shutter. Both systems exist with and without anti-lift devices.

[Also, smartphone app control is by no means standard everywhere – it is a "gadget" you can have but do not necessarily need.

Regarding the basement: every living space needs its own escape route in case of fire. So if the basement is to be used as living space, every single basement room must have an escape-compliant window facing outside. And if it is a real basement, i.e., underground, you need light wells (with windows) for that. Where rotting leaves and vermin collect, grid on top or not. And where burglars can theoretically enter unnoticed.

Sorry, that is not true. I must prove a second escape route on every floor where living spaces exist. Not necessarily in every room.

Instead of light wells, I can also build a light shaft, and even if light wells are used, there have been cover options made of plexiglass for some time now (not ideal due to lack of ventilation) or grids with a fine insect screen inside, so that nothing can fall into the light well anymore.

Having your own photovoltaic system is of course nice (if the power goes out, you simply switch from feed-in to self-consumption and still get the shutters open), but maybe you should rather use a combination with solar collectors for heat generation. Probably more effective in winter.

You cannot just switch a photovoltaic system from feed-in to self-consumption during a power outage – that only works with a system that has its own power storage (battery). A photovoltaic system without a battery is simply "dead" during a power outage because the inverter needs control voltage from outside.

Since the OP is already favoring a ground or air-water heat pump, the suggestion to add solar thermal for heat generation is not really productive. The heat pump reliably produces heat with the electricity from the photovoltaic system – so additional collectors are quite unnecessary. I would rather put a few more photovoltaic modules on the roof.

Moreover, given the current feed-in tariffs, it is pretty foolish to feed everything into the grid, as the feed-in compensation is now significantly lower than the price for purchased electricity. Therefore, photovoltaic systems are nowadays standardly operated in the "surplus feed-in" mode...

Regards,

Dirk