Hello,
our family owns a house on a hillside. We are currently considering adding extra parking spaces / carports (e.g., 2-3 parking spots plus a bike shed) on the property for personal use and guests. The planned area would be located directly along the property line facing the street, allowing direct access from the street to the parking spaces / carports. Due to the hillside location, a significant amount of soil would need to be excavated (initial rough estimate about 240 m³ (310 cubic yards)) and a retaining wall would have to be built to resist earth pressure. I roughly sketched the idea in the attached images (not to scale). According to the soil report from the original house construction, aside from a thin top layer of topsoil, only layers of claystone (decomposed/weathered) and sandstone should be expected (no rock or similar).
We are first looking for a rough cost estimate, especially concerning the earthworks and retaining wall construction—that is, the cost of creating the parking spaces alone (without carports). In this context, I am curious if anyone has done something similar and could share some initial experiences. Experienced users might also share their gut feeling, as I really have no sense of the potential size of the project. Many thanks in advance for any input!
our family owns a house on a hillside. We are currently considering adding extra parking spaces / carports (e.g., 2-3 parking spots plus a bike shed) on the property for personal use and guests. The planned area would be located directly along the property line facing the street, allowing direct access from the street to the parking spaces / carports. Due to the hillside location, a significant amount of soil would need to be excavated (initial rough estimate about 240 m³ (310 cubic yards)) and a retaining wall would have to be built to resist earth pressure. I roughly sketched the idea in the attached images (not to scale). According to the soil report from the original house construction, aside from a thin top layer of topsoil, only layers of claystone (decomposed/weathered) and sandstone should be expected (no rock or similar).
We are first looking for a rough cost estimate, especially concerning the earthworks and retaining wall construction—that is, the cost of creating the parking spaces alone (without carports). In this context, I am curious if anyone has done something similar and could share some initial experiences. Experienced users might also share their gut feeling, as I really have no sense of the potential size of the project. Many thanks in advance for any input!
MrsAndMr schrieb:
a few tens of thousands"I don’t think your costs will reach six figures, but you can probably expect a high five-figure amount.
We received a quote for 26 meters (85 feet) of retaining wall with 180cm (71 inches) high L-shaped blocks and 14 meters (46 feet) of retaining wall with blocks ranging from 155 to 80cm (61 to 31 inches) in height, including 50 cubic meters (65 cubic yards) of excavation and disposal, just under 45,000.
Our expenses so far (with a company whose owner is a very good friend of our close friend 🙂 ) are around 20,000 plus about 1,500 for excavation and disposal. However, he sold us the L-shaped blocks at cost price, so it’s already a very good deal.
Our experience has been that it’s very difficult to find contractors for small and complicated projects.
Therefore, I think it might be an even greater challenge to find the right company.
W
WilderSueden21 May 2022 22:57How much space do you have between the parking area and the house, and what is the height difference we're talking about? The issue isn’t just that the finished structure has to be stable; you also need to be able to secure it during the construction phase. This makes me wonder whether the slope can actually be graded. Usually, a retaining wall leans into the slope, which means you’ll need about one meter (3 feet) more space than you might expect.
Your sketch reminded me of a snapshot from a vacation:
Your sketch reminded me of a snapshot from a vacation:
i_b_n_a_n schrieb:
I would first check whether you’re allowed to build like that. The proximity to the road might prohibit such parking spaces since you can only back out onto the road, which could endanger the flowing traffic (or reverse parking...). On federal roads, this is not allowed; a district road would probably be OK (in NRW).
This was actually a problem in a family construction project recently. They had to create space (house also on a (steep) slope) to be able to park parallel to the road.The building permit is not yet granted – but there is a “good connection” to the building authority, and a verbal preliminary approval has been given for the project.hanse987 schrieb:
Is the sidewalk lowered? If not, is it even allowed to lower it at that point for a driveway?Yes, it is already lowered! In the old building permit for the house, parking spaces at that location were already approved.Yaso2.0 schrieb:
I don’t think your costs will reach six figures, but a high five-figure amount is probably to be expected.
We had a quote for a 26m (85 ft) retaining wall with 180cm (6 ft) high angle blocks and a 14m (46 ft) retaining wall with blocks between 155cm and 80cm (5 ft 1 in to 2 ft 7 in), 50 cubic meters (65 cubic yards) of excavation plus disposal, totaling just under 45k. Our current costs (with a company whose owner is a very good friend of a very good friend of ours 🙂 ) amount to around 20k plus about 1.5k for excavation plus disposal. He let us have the angle blocks at his purchase price, so that was already a very good deal.
Our experience was that it’s very difficult to find companies for small and especially challenging projects.
Therefore, I think finding the right company might be a bigger challenge.Our slope is probably much steeper, so it likely involves a significantly larger amount of soil. But this is still valuable information, thanks for sharing your experience! I also fear it won’t be easy to find an excavation contractor for this project.WilderSueden schrieb:
How much space do you have from the parking space to the house, and what height difference are we talking about? The problem is not only that the finished structure must hold, you also have to be able to secure it during construction. This raises the question of whether it can even be terraced. Retaining walls are usually inclined towards the slope, so you’ll likely need about a meter (3 ft) more space than you might expect.
Your sketch reminded me of a snapshot from a vacation:The space in front of the parking space is probably about 1.5–2m (5–6.5 ft) – I hope that’s enough for terracing. The slope itself actually looks quite similar to the photo. The height difference between the street level and the first house entrance is about 5m (16 ft) over a length of roughly 8m (26 ft), which means the slope angle is around 32 degrees.Similar topics