ᐅ Semi-detached house in Hamburg with a general contractor on own land, two plus full attic floors, no basement
Created on: 26 Jul 2025 12:27
1
1689owen
I’m looking for feedback on anything we might have overlooked. Tips on processes and organization are also helpful. (Details about the location, plot, and contractors involved will be shared later to keep things anonymous for now.)
We want to build a duplex and hire a general contractor (GC) for this. Each party has about €40,000 (approximately $44,000) available. The scope of self-performed work will differ slightly between the two parties but will mainly be limited to painting (including plastering and all related work) and flooring (excluding bathrooms). The attic may possibly be finished as self-performed work.
We have a few requirements:
According to the plans, we may build two full stories. We want to retain as much garden space as possible and, for this reason among others, would like to add a fully functional attic. By “fully functional,” we mean it can be used as living and working space and forms its own separate part of the apartment—not an open area connected to the stairwell (for example, the parents’ bedroom would be here). We were advised that having a concrete floor between the upper floor and attic would be sensible to achieve this. The attic could also be raised with a knee wall (dormer wall), which would greatly improve the interior height. Since the plans don’t specify maximum ridge, eaves, or gable heights, it will likely be restricted only by required setback distances. The setback to the neighboring plot is currently set at 3 meters (about 10 feet) for driveway, bike storage, and garage as border construction. This leaves a good garden area on the other side of the house.
kfw300 program:
This is very helpful for financing, almost essential for us. However, it comes with certain requirements that may cause additional costs. Which parameters would you recommend adjusting here?
Current status:
We have discussed financing preliminarily and set a budget framework. We already own the land. We are currently in talks with several GCs (ranging from smaller architecture firms, medium-sized companies, to larger firms like Baudirekt). We plan to decide on a GC in about a month. The options each GC offers will understandably influence our decision. We also still need to clarify whether we truly need and can afford a fully finished attic or if a pitched roof attic that could be finished later would suffice. A basement would probably be more expensive and provide less livable space than a full attic, so it is no longer a serious option. We plan to consult two or three more GCs to get feedback on possibilities and pricing.
Please feel free to ask any questions! This is already a lot of help. Maybe there’s even some additional advice out there. Thanks!
We want to build a duplex and hire a general contractor (GC) for this. Each party has about €40,000 (approximately $44,000) available. The scope of self-performed work will differ slightly between the two parties but will mainly be limited to painting (including plastering and all related work) and flooring (excluding bathrooms). The attic may possibly be finished as self-performed work.
We have a few requirements:
- Each party: 2 adults (bedroom, office) + 3 children (individual bedrooms)
- Total house footprint around 165m² (approximately 1,775 sq ft). A preliminary building inquiry has already been made.
- Noise protection necessary due to aircraft noise.
- Full attic living space
- kfw300 program
- Solid construction
- Brick facade
- Pitched roof
- Central ventilation system
- For both parties: rooms should not be too large (e.g., child’s room 10m² (110 sq ft), office 8m² (86 sq ft)); only one large open area for living and kitchen.
- Each half of the building should be easily separable in the future into an accessible unit (basement) and an apartment (upper floor + attic).
According to the plans, we may build two full stories. We want to retain as much garden space as possible and, for this reason among others, would like to add a fully functional attic. By “fully functional,” we mean it can be used as living and working space and forms its own separate part of the apartment—not an open area connected to the stairwell (for example, the parents’ bedroom would be here). We were advised that having a concrete floor between the upper floor and attic would be sensible to achieve this. The attic could also be raised with a knee wall (dormer wall), which would greatly improve the interior height. Since the plans don’t specify maximum ridge, eaves, or gable heights, it will likely be restricted only by required setback distances. The setback to the neighboring plot is currently set at 3 meters (about 10 feet) for driveway, bike storage, and garage as border construction. This leaves a good garden area on the other side of the house.
kfw300 program:
This is very helpful for financing, almost essential for us. However, it comes with certain requirements that may cause additional costs. Which parameters would you recommend adjusting here?
Current status:
We have discussed financing preliminarily and set a budget framework. We already own the land. We are currently in talks with several GCs (ranging from smaller architecture firms, medium-sized companies, to larger firms like Baudirekt). We plan to decide on a GC in about a month. The options each GC offers will understandably influence our decision. We also still need to clarify whether we truly need and can afford a fully finished attic or if a pitched roof attic that could be finished later would suffice. A basement would probably be more expensive and provide less livable space than a full attic, so it is no longer a serious option. We plan to consult two or three more GCs to get feedback on possibilities and pricing.
Please feel free to ask any questions! This is already a lot of help. Maybe there’s even some additional advice out there. Thanks!
Papierturm29 Jul 2025 17:0011ant schrieb:
How is that supposed to work? Well, a relative standard. Fixed prices tiered for project phases 1-3 (always combined), phase 4 (full), and parts of later phases.
But it depended on what the general contractors (GCs) actually did. As soon as the GCs didn’t take on much, it naturally became significantly more expensive, and he would have also charged according to the HOAI fee scale.
When did I write that? Sorry, I must have misunderstood.
That Germany could cast the super general contractor with this. That would be an interesting new show idea!
That wasn’t what I meant either.
What I was trying to say:
If two GCs submit bids for quite different houses (external dimensions, windows, fittings, etc.), they are hard to compare.
That was the result despite all efforts when we tried to get offers without providing prior planning. (Not to mention that many GCs were really good at ignoring the zoning plan and what had been previously discussed.)
Trockenbauwarzen produziert. ... what does that mean exactly?
I think the wishlist needs to be trimmed down first, or the budget increased. Also, limitations like 80sqm (860 sq ft) of floor space are usually a hindrance in the planning of tightly budgeted construction projects. It is better to give the architect full freedom and mention that you would like to have a garden as well. You can be more specific, such as a terrace and vegetable patch, or just a terrace for one person, while another might want a soccer field, and so on.
Papierturm schrieb:
Sorry, I must have summarized that incorrectly. This might have happened because I was partly unclear in my explanations. Could you show me (by quoting post numbers or similar) where you saw the misunderstandings?
Papierturm schrieb:
What I meant is this: If two main contractors submit bids for quite different houses (external dimensions, windows, fittings, and so on), then those offers are difficult to compare. There are independent building consultants (at least for prefabricated houses—I have mentioned some colleagues here several times before) who can provide a shortlist, so you don’t end up comparing, say, a Mazda with a Maserati across different classes. Usually, just one conversation (or a few thread exchanges) is enough for an expert to identify which providers match the type of building family. This way, statistical outliers can be avoided in advance. It costs far less than hiring an architect to create a template for the main contractor. A bigger obstacle to comparability than differing dimensions are inconsistencies in the building specification, which cannot be fixed simply by defining the building shell.
How close are you to finalizing your goals?
Papierturm schrieb:
... what exactly does that mean? When builders are expected to work from building permit drawings, too many questions remain open, or there is a risk that those will be handled “ad hoc” using whatever method is most convenient at the time. Without a slot in the wall, the downpipe ends up simply placed in front of it and boxed in with drywall.
K a t j a schrieb:
I think the wishlist first needs to be cut down significantly. To cut it down, the wishlist first needs to be made clear and concrete.
K a t j a schrieb:
Besides, restrictions like an 80sqm (860sq ft) floor area limit are usually a hindrance for tightly budgeted construction projects during planning. Sort of. The typical 140/145sqm (1507/1562sq ft) II+D SD35-38 semi-detached house from the usual suspects measures about 6m (20 ft) wide per half by 12.5m (41 ft) deep, so it doesn’t come close to that “eighty” mark; and here, the number of storeys could even be more generous (although the original poster has not yet provided a buildable house profile).
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
I’m checking in after a longer “break,” as the experienced ones already predicted:
We definitely didn’t want to fall on our face. Still, we’re feeling a bit lost (though it is slowly getting better).
We have completed several agreements with construction companies and architects; some are still ongoing. A plan that considers both our financial expectations and space requirements is still missing. However, we hope we now have a clearer idea of what is important to us.
-I’ll fill out the list that would have been really helpful at the start and report from the preliminary decision as well.
-I’m also attaching rough sketches of the plot [ERROR IN THE GREY 14 IN THE MIDDLE, SHOULD BE 16] (regardless, all figures are quite approximate) and the planned number of floors/setbacks.
-Some things are probably still missing – so please feel free to ask!
-At the end, I’ll list some questions and ideas for the next steps.
Development Plan / Restrictions
Plot size: approx. 700 m² (7,535 ft²)
Slope none
Site coverage ratio 0.4 (secured by preliminary decision)
Floor area ratio none
Building line, building boundary and construction limits see sketch; the preliminary decision indicates building is allowed up to the red lines (the corner plot may use the building boundaries of both intersecting streets)
Edge development none
Number of parking spaces no requirements
Number of floors II + attic permitted
Roof style no restrictions
Architectural style no restrictions
Orientation no restrictions
Maximum heights / limits no specific requirements, limited by setback distances
Other requirements none known
Additional requirements Hamburg mandates solar panels plus noise protection due to aircraft noise
Clients’ Requirements
Architectural style, roof type, building type: semi-detached house with pitched roof
Basement, floors no basement, II + attic, plus optionally a loft space for storage above
Number of persons, ages each household: parents (mid-30s), three children (ages 0 to 8)
Space requirements on ground floor (GF), upper floor (UF) and attic: Each household needs a living-dining area with kitchen, utility/technical room, guest bathroom (one with shower), family bathroom, two children’s bedrooms immediately plus a third later, parents’ bedroom, office (mostly for home office)
Office use: family or home office? Home office, as above
Overnight guests per year Variable; relatives nearby may provide space. Ideally more guests, but not realistically planned for in current space requirements
Open or closed layout living-dining area open; one unit with open staircase, the other closed
Conservative or modern construction ?
Open kitchen, kitchen island open kitchen, possibly partial island
Number of dining seats We often eat with up to 10 people
Fireplace no
Music/stereo wall no, no TV in living area either
Balcony, roof terrace currently excluded
Garage, carport preferably garage/shed for many bicycles for both households together, possibly a carport later on
Garden design, utility garden, greenhouse terraces for both, a small vegetable patch, decorative planting at the garden edges, rest of garden open for children to play
Additional wishes kfw300
House Design
More details hopefully coming in the next few weeks.
Personal price limit for the house, including equipment: Financing realistically only possible with the kfw300 program within the stated budget (around €400,000 (about $440,000) maybe up to €420,000 (about $463,000) per half including ancillary costs). Otherwise, lower.
Preferred heating technology: air-to-water heat pump (kfw)
If you have to give up something, on which details/extensions
-can you live without: Rooms (except the living-dining area on the ground floor) do not need to be large; small bedrooms are fine. We discussed the idea of separating the ground floor, which is now discarded; otherwise, one household would like a master bathroom (plan is parents on attic floor with bedroom and private bath), but can give that up if necessary. A roof terrace was once considered for one household but is currently willingly dropped in favor of a simpler roof design.
-cannot give up: number of rooms.
Why is the design like it is now?
The II + attic idea comes from needing a certain number of rooms. It’s also appealing because in case of cost issues, parts of the attic could be finished later by ourselves. Originally, we considered II + stepped floor with a roof terrace, but that was more expensive in many offers. We can all live with the pitched roof as long as there is enough headroom in the center of the attic. The pitched roof also offers storage (knee walls, loft space). A basement is not affordable, and with II + attic and garage/shed, we’d at least have space for all our stuff. Of course, I + attic or II without attic could be options too. But we don’t like I + attic if there’s not enough knee wall height (we want to be able to stand everywhere), and both I + attic and II without attic require bigger floor plates, which reduces garden space and increases roof area (and costs). We’ve also discussed this with architects – I don’t remember all the reasons offhand, but they also tend to prefer II + attic.
The driveway should be about 3 meters (about 10 feet) wide, as a setback distance, so as narrow as possible because the area receives little sunlight. The N/S orientation in the sketch is incorrect; south is roughly to the left.
Number of floors is not a major issue as shown in the profile if the roof ridge runs parallel to the driveway. Then the setback distances can be calculated as (3+3+1/3*4)*0.4=2.94, for example.
Maybe now it’s a little easier to cut the wishlist. I feel like I can’t see the forest for the trees right now. So I might have overlooked something – please just ask.
This is probably our main concern: Does the budget have to stay fixed? How much would it need to be increased? What expectations about a semi-detached house must we abandon? Which wishes are explicit or implicit and should be discarded?
And regarding a few questions from @ypg:
There isn’t one yet. All catalog home modifications are too expensive. Architects are working on it, but the first draft was way too big and therefore (estimated) far too costly.
The inquiry aimed to clarify building boundaries and site coverage ratio. See sketch. The plot will be divided along the party wall; not necessarily exactly half.
Hopefully answered above. One child’s room can come later.
A financing advisor. That is our total budget. With kfw300, maybe a bit more (up to €420,000 (~$463,000), for one half possibly €450,000 (~$496,000)). Without kfw, less. Incidental costs should be included. Landscaping may be done later or by family own efforts/grants.
Rübe1 schrieb:
zaubert, according to which:
[Next month decide on general contractor]
is completely unrealistic alongside the costs. Unless you want to take a hard fall...
We definitely didn’t want to fall on our face. Still, we’re feeling a bit lost (though it is slowly getting better).
We have completed several agreements with construction companies and architects; some are still ongoing. A plan that considers both our financial expectations and space requirements is still missing. However, we hope we now have a clearer idea of what is important to us.
-I’ll fill out the list that would have been really helpful at the start and report from the preliminary decision as well.
-I’m also attaching rough sketches of the plot [ERROR IN THE GREY 14 IN THE MIDDLE, SHOULD BE 16] (regardless, all figures are quite approximate) and the planned number of floors/setbacks.
-Some things are probably still missing – so please feel free to ask!
-At the end, I’ll list some questions and ideas for the next steps.
Development Plan / Restrictions
Plot size: approx. 700 m² (7,535 ft²)
Slope none
Site coverage ratio 0.4 (secured by preliminary decision)
Floor area ratio none
Building line, building boundary and construction limits see sketch; the preliminary decision indicates building is allowed up to the red lines (the corner plot may use the building boundaries of both intersecting streets)
Edge development none
Number of parking spaces no requirements
Number of floors II + attic permitted
Roof style no restrictions
Architectural style no restrictions
Orientation no restrictions
Maximum heights / limits no specific requirements, limited by setback distances
Other requirements none known
Additional requirements Hamburg mandates solar panels plus noise protection due to aircraft noise
Clients’ Requirements
Architectural style, roof type, building type: semi-detached house with pitched roof
Basement, floors no basement, II + attic, plus optionally a loft space for storage above
Number of persons, ages each household: parents (mid-30s), three children (ages 0 to 8)
Space requirements on ground floor (GF), upper floor (UF) and attic: Each household needs a living-dining area with kitchen, utility/technical room, guest bathroom (one with shower), family bathroom, two children’s bedrooms immediately plus a third later, parents’ bedroom, office (mostly for home office)
Office use: family or home office? Home office, as above
Overnight guests per year Variable; relatives nearby may provide space. Ideally more guests, but not realistically planned for in current space requirements
Open or closed layout living-dining area open; one unit with open staircase, the other closed
Conservative or modern construction ?
Open kitchen, kitchen island open kitchen, possibly partial island
Number of dining seats We often eat with up to 10 people
Fireplace no
Music/stereo wall no, no TV in living area either
Balcony, roof terrace currently excluded
Garage, carport preferably garage/shed for many bicycles for both households together, possibly a carport later on
Garden design, utility garden, greenhouse terraces for both, a small vegetable patch, decorative planting at the garden edges, rest of garden open for children to play
Additional wishes kfw300
House Design
More details hopefully coming in the next few weeks.
Personal price limit for the house, including equipment: Financing realistically only possible with the kfw300 program within the stated budget (around €400,000 (about $440,000) maybe up to €420,000 (about $463,000) per half including ancillary costs). Otherwise, lower.
Preferred heating technology: air-to-water heat pump (kfw)
If you have to give up something, on which details/extensions
-can you live without: Rooms (except the living-dining area on the ground floor) do not need to be large; small bedrooms are fine. We discussed the idea of separating the ground floor, which is now discarded; otherwise, one household would like a master bathroom (plan is parents on attic floor with bedroom and private bath), but can give that up if necessary. A roof terrace was once considered for one household but is currently willingly dropped in favor of a simpler roof design.
-cannot give up: number of rooms.
Why is the design like it is now?
The II + attic idea comes from needing a certain number of rooms. It’s also appealing because in case of cost issues, parts of the attic could be finished later by ourselves. Originally, we considered II + stepped floor with a roof terrace, but that was more expensive in many offers. We can all live with the pitched roof as long as there is enough headroom in the center of the attic. The pitched roof also offers storage (knee walls, loft space). A basement is not affordable, and with II + attic and garage/shed, we’d at least have space for all our stuff. Of course, I + attic or II without attic could be options too. But we don’t like I + attic if there’s not enough knee wall height (we want to be able to stand everywhere), and both I + attic and II without attic require bigger floor plates, which reduces garden space and increases roof area (and costs). We’ve also discussed this with architects – I don’t remember all the reasons offhand, but they also tend to prefer II + attic.
The driveway should be about 3 meters (about 10 feet) wide, as a setback distance, so as narrow as possible because the area receives little sunlight. The N/S orientation in the sketch is incorrect; south is roughly to the left.
Number of floors is not a major issue as shown in the profile if the roof ridge runs parallel to the driveway. Then the setback distances can be calculated as (3+3+1/3*4)*0.4=2.94, for example.
K a t j a schrieb:
I think the wishlist needs to be cut back first or the budget needs to be increased
Maybe now it’s a little easier to cut the wishlist. I feel like I can’t see the forest for the trees right now. So I might have overlooked something – please just ask.
This is probably our main concern: Does the budget have to stay fixed? How much would it need to be increased? What expectations about a semi-detached house must we abandon? Which wishes are explicit or implicit and should be discarded?
And regarding a few questions from @ypg:
ypg schrieb:
Come on, show the design!
There isn’t one yet. All catalog home modifications are too expensive. Architects are working on it, but the first draft was way too big and therefore (estimated) far too costly.
ypg schrieb:
Now I wonder, what exactly does the building preliminary inquiry concern, who requested and commissioned it? Was it done before the purchase? Did only one person buy the plot and does that person sell one half to the other? Does the preliminary inquiry concern a single-family house or a semi-detached house? Is there already a design? Will the plot be divided exactly in half? What is the plot orientation? Was the orientation considered in the preliminary inquiry or was it simply based on site coverage and floor area ratios? Were parking spaces requested? How many parking spaces do you need? How many must you have?
The inquiry aimed to clarify building boundaries and site coverage ratio. See sketch. The plot will be divided along the party wall; not necessarily exactly half.
ypg schrieb:
Do you have to have the rooms finished upon move-in? Are the children born? Could they initially share a room because they are young? Does there have to be an office because home office is important?
Hopefully answered above. One child’s room can come later.
ypg schrieb:
Are construction incidental costs and outdoor work costs already deducted from the €400,000 (about $440,000)? That means: after €400,000 expenditure do you still have enough to cover incidental costs and landscaping?
ypg schrieb:
What exactly do the approximately €400,000 (about $440,000) refer to? Is that an assumption or calculated by a bank or Dr. Klein?
A financing advisor. That is our total budget. With kfw300, maybe a bit more (up to €420,000 (~$463,000), for one half possibly €450,000 (~$496,000)). Without kfw, less. Incidental costs should be included. Landscaping may be done later or by family own efforts/grants.
N
nordanney21 Oct 2025 15:331689owen schrieb:
Space requirements on the ground floor (GF), first floor (FF), and attic (attic floor): Each household needs a combined living and dining area with kitchen, utility/technical room, guest bathroom (one household with a shower), family bathroom, two children's bedrooms initially and later a third children's bedroom, master bedroom, office (a lot of home office)3 children's bedrooms = 33sqm (355 sq ft) 1 master bedroom = 15sqm (160 sq ft)
1 family bathroom = 15sqm (160 sq ft)
1 hallway = 6sqm (65 sq ft)
==> total on the first floor = 69sqm (742 sq ft)
The same living area on the ground floor (including technical room and home office) = approx. 140sqm (1,507 sq ft) at a construction cost of €3,000 plus additional building-related costs, garage/carport, outdoor landscaping/paving of driveway/entrance, terrace. I think even the "budget builders" (offering only the basics) will not meet this requirements profile.
==> This does not fit the budget
I see only one solution: substantial self-performed work
Even though the third children's bedroom is only needed "later," the space has to come from somewhere.
Just my opinion:
Overnight guests/dinner guests: Are you building the house for yourselves or for your visitors? Do you have an idea of how often you can go out to eat or send them to a hotel before the additional costs for those otherwise unused square meters are covered? Especially when the budget is limited, as in this case.
Regarding the KfW standard: 300 is required. With the photovoltaic requirement, that becomes 40+.
Then there’s at least the D part prepared for finishing (meaning insulated, ceiling, stairs, wiring, etc.) fixed and for 400 in Hamburg? No. Not with these individual requests.
I just saw: the building plot is 12 by 18 meters (39 by 59 feet), is that the plot size for the entire house or for half? I can’t quite figure it out from the “site plan” when they say it should be 700 square meters (7,535 square feet)...
Overnight guests/dinner guests: Are you building the house for yourselves or for your visitors? Do you have an idea of how often you can go out to eat or send them to a hotel before the additional costs for those otherwise unused square meters are covered? Especially when the budget is limited, as in this case.
Regarding the KfW standard: 300 is required. With the photovoltaic requirement, that becomes 40+.
Then there’s at least the D part prepared for finishing (meaning insulated, ceiling, stairs, wiring, etc.) fixed and for 400 in Hamburg? No. Not with these individual requests.
I just saw: the building plot is 12 by 18 meters (39 by 59 feet), is that the plot size for the entire house or for half? I can’t quite figure it out from the “site plan” when they say it should be 700 square meters (7,535 square feet)...
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