TobsBAU
2024-01-28 19:38:06
- #1
Hello everyone,
I am new to the forum and have purchased a plot of land from the municipality in a new development area, which is to be built on with a single-family house in the next 1.5 years (1.5 or 2 stories).
However, I have been stuck for some time on the issue of the plot conditions (slight slope and below street level) and the associated question of whether a basement in the present situation might after all be the smarter/more cost-effective (or at least cost-neutral) solution. To answer this question comprehensively, offers from civil engineers and especially a soil survey are probably necessary. However, on the subject of the soil survey, I am going around in circles because all soil surveyors want as exact specifications as possible regarding the planned construction, which in turn depends on the decision about a basement or slab foundation.
I am hoping for advice on the following questions:
All prefab house providers etc. I have been in contact with so far have really not responded to these conditions, ask for a budget frame, and then assume a flat rate of €25,000 for the earthworks etc. I suspect that will not be enough and I want to make these costs tangible for financial planning! When the subject of a basement is raised, even architects generally say a basement is always expensive. If the budget is tight, forego the basement...
I don’t want to withhold the following information and premises from you:
Thank you very much and I look forward to suggestions and advice!
I am new to the forum and have purchased a plot of land from the municipality in a new development area, which is to be built on with a single-family house in the next 1.5 years (1.5 or 2 stories).
However, I have been stuck for some time on the issue of the plot conditions (slight slope and below street level) and the associated question of whether a basement in the present situation might after all be the smarter/more cost-effective (or at least cost-neutral) solution. To answer this question comprehensively, offers from civil engineers and especially a soil survey are probably necessary. However, on the subject of the soil survey, I am going around in circles because all soil surveyors want as exact specifications as possible regarding the planned construction, which in turn depends on the decision about a basement or slab foundation.
I am hoping for advice on the following questions:
[*
- Can the excavation from building with a basement be used to fill up the plot to street level (no chargeable disposal)?
[*]What advice can you give me regarding the soil survey (exact later construction not yet fixed)?
[*]I am wavering between the following scenarios (which do you consider more sensible?):
[LIST=1]
[*]Basement and filling the plot to street level with excavation (catch the northeast plot boundary with 1 m high L-shaped concrete blocks), allowing partial slope to the northeast to create a basement room with daylight that could possibly be used as an office. The technical room would of course also be in the basement, but I would like to avoid a lifting station if possible!?
[*]Filling the plot (up to street level or slightly below) and building with a slab foundation (catch the northeast plot boundary with 1 m high L-shaped concrete blocks). However, I am concerned about the costs of the fill material and the necessary compaction. Technical room on the ground or upper floor, no lifting station, but probably a backwater valve.
All prefab house providers etc. I have been in contact with so far have really not responded to these conditions, ask for a budget frame, and then assume a flat rate of €25,000 for the earthworks etc. I suspect that will not be enough and I want to make these costs tangible for financial planning! When the subject of a basement is raised, even architects generally say a basement is always expensive. If the budget is tight, forego the basement...
I don’t want to withhold the following information and premises from you:
[*]The plot lies below street level. The adjacent neighboring plot (southeast) was filled up to street level (OK RF EG +156.14 m).
[*]Due to the filling to street level, a backwater valve could be dispensed with. On the opposite plot (northwest, behind the sidewalk), it was not filled as high, so a backwater valve had to be installed there. With construction including a basement, even with filling to street level, I would probably have to calculate on a lifting station.
[*]According to the development plan, a retaining wall of up to one meter high may be built to catch the slope; beyond that, slope angles of 30 ° must be observed (see attachment). Of course, both neighboring plots have made use of this and have set corresponding L-shaped blocks on the northeast side.
[*]Basically, I would not necessarily have filled in, but since the plot was raised on the southeast side to this extent and the main light naturally comes from there, I almost see myself forced to at least partially fill in.
[*]Deviating from the neighboring development, I am considering placing the house (gable roof) with the gable perpendicular to the street (see sketch). The plot would then be better lit and more usable.
[*]Northeast, there is a castle at some distance which should also be considered in the planning of the house (view connection).
[*]The plot is 464 m² and located 800 m from a watercourse (approx. 15 m above the water surface, no flooding risk). Additional sealing measures on a basement are assumed (probably even a “white tub” [waterproof concrete box]). A neighbor who built with a basement had to seal from the outside (probably afterwards).
[*]The development plan is generally quite generous: 2 full stories allowed, THmax = 6.5 m, FHmax = 10.5 m, floor area ratio: 0.4
[*]Surveying is available (see attachment)
Thank you very much and I look forward to suggestions and advice!