ᐅ Floor plan, post-and-beam construction, accessory dwelling unit, and existing building
Created on: 21 Feb 2023 20:48
B
BucheOnBoard
Hello everyone,
Currently, my father, my wife, and my child (under 1 year old) live in a small residential house from the 1950s with 61m² (655 sq ft) of living space. The property is owned 50/50 by my father and me but is still partly being paid off by my grandmother (my outstanding payments are held in a separate account and are therefore just a “pass-through” item, while my father pays his monthly installments from his income). The plot is in Hamburg Iserbrook and measures 681m² (7,333 sq ft) with a standard land value of €985.
Unsurprisingly, the space is becoming somewhat tight, even though we get along well. Furthermore, the health of the older housemate is declining, and the narrow staircase to the upper floor is already becoming difficult to manage.
The basic idea is this: I would receive the second half of the plot as a gift, debt-free. My father will continue paying off his installments until he inherits the remainder. In return, we will build him a nice accessory apartment with the corresponding right of residence (or usufruct right, which still needs to be clarified)—barrier-free and compact so he can live independently there for as long as possible. The rest of the ground floor would then only contain a multipurpose room, guest toilet, and hallway; upstairs four rooms and a bathroom. We would like a (simple) converted attic as a retreat area. To relieve the ground floor space and avoid fully using the building envelope (sealing of surfaces, etc.), we plan a basement, as there are also two space-intensive hobbies and a workshop desired for DIY projects. I will also build some of the furniture myself.
Now to the questionnaire:
Building Plan / Restrictions
Plot size: 681m² (7,333 sq ft) with existing house
Slope: No, but the area from the street level up to the terrace is filled +90cm (35 inches), the garage is at about +40cm (16 inches), the neighboring plot to the north also about +40cm (16 inches), and to the south approximately at street level
Floor area ratio (FAR): 0.4
Plot ratio (building coverage ratio): 0.4
Building envelope, building line, and boundaries: 5m (16.4 ft) setback to the street, then 15m (49.2 ft) deep, 2.5m (8.2 ft) setback on each side (more for taller buildings)
Edge development: Allowed (garages etc., max. wall height 3m (10 ft), max. length 9m (30 ft))
Number of parking spaces: We believe none are legally required; we plan to provide one for future use, for electric vehicle charging (currently not needed)
Number of floors: One full story; ALKIS shows some buildings apparently with two floors (see attachment)
Roof type: Not specified
Architectural style: Not specified
Orientation: Not specified
Maximum heights/limits: Not specified
Other requirements: No illuminated advertising signs 😉
The 1965 building plan mainly mandates “residential zoning only” and “one full story,” but even these rules seem flexible. There is a very large copper beech tree in the southeast corner of the plot, with an estimated crown diameter of 10m (33 ft) and at least 12-14m (39-46 ft) tall. The tree is to be preserved (it is unclear if it must officially be preserved with a new build). I expect that the new building must not come closer to the tree than the current building—about 2.5m (8.2 ft) from the trunk. The trunk itself is roughly 1.5m (5 ft) in diameter. A pruning plan is under discussion (also due to shading of the roof, planned for solar panels).
Owners' Requirements
Architectural style, roof shape, building type: Detached single-family home, gable roof with pitch >45°, rather long and narrow
Basement, number of floors: Yes to basement, 1.5 floors plus a converted attic
Number of occupants, ages: 4 (64 (gruff and private), 34, 31, under 1) Another child should be possible
Ground floor space needs: Open-plan area preferably with a small pantry, guest toilet
Accessory apartment with barrier-free design (walk-in shower, open living kitchen with sleeping niche). Can be small.
Shared hallway important (for potential care needs without going outside, access to joint basement with laundry facilities, etc.)
Upper floor space needs: 1 bedroom with a large bed and built-in closets but no extras, 3 rooms (1 child’s room, 1 office/child’s room, 1 guest/office (can be small)), 1 bathroom with a larger vanity, bathtub, and shower
Attic space needs: 2 “retreat” areas for the adults; if necessary, just a rocking chair with reading lamp and sewing machine on one side, and a gaming PC on the other. The current attic is an equilateral triangle with 2.1m (83 inches) side length; it doesn’t need to be much larger/wider/higher than that.
Basement space needs (access via shared hallway + additional exterior entrance): Technical room with heat pump, ventilation, electrical distribution, inverter, server; woodwork workshop; laundry room; 2 hobby cellars for large-format collections—Lego and beer cans, no kink-shaming please 😉 ; 1 storage room for decorations, suitcases, camping gear, etc. Must be heated (and ventilated), but simple tile flooring and surface-mounted installations are sufficient.
Office: Family use or home office? Home office about three times a week, plus one self-employed side business
Guest stays per year: 6–10, usually just one night, sometimes 2–3 nights
Open or closed design: Open on the ground floor but staircase not located in the living room/open space
Conservative or modern construction? I’m never quite sure of the difference, but I feel fully modern
Open kitchen, kitchen island: Yes, cooking often and joyfully, also with guests
Number of dining seats: 6; existing table extends to 14 seats for Christmas and birthdays
Fireplace: No, no chimney planned
Music/stereo wall: No
Balcony, roof terrace: No
Garage, carport: Carport/roof overhang directly at the building would be good, mainly for bikes and potentially for an electric vehicle in the (near) future. To my knowledge, Hamburg does not require parking spaces.
Vegetable garden, greenhouse: Maybe a small bed later, but not important at the moment
Other wishes/particularities/daily routine, including reasons for certain choices: Currently, leisure activities happen at the dining table, which is between sofa and TV (used about once a week), so large lounge furniture is not really needed. The tree is a critical factor, as it likely narrows the building envelope in the front area to about 6.5m (21 ft). We don’t want to move the house further back because of the garden.
House Design
Planner: Still in the very early idea phase. Overall, we think about 180m² (1,937 sq ft) of living space plus basement. We currently live as four on 61m² (655 sq ft) and can manage. We don’t need huge increases in room size, rather a spatial separation with the accessory apartment and space for hobbies and home office. Dressing rooms or a children’s bathroom are not planned.
Personal budget limit for house including fittings: €750,000–800,000 (USD amount varies), with much furniture available from the existing house. Demolition cost would be extra, but I see plenty of grants and rental expenses during construction period. €450,000 (about $480,000) equity is available; the plot described above would be fully paid off (worth almost €700,000 or approximately $750,000).
Preferred heating technology: Ground-source heat pump with deep borehole and 12–15kWp photovoltaic system plus centralized controlled residential ventilation with enthalpy heat exchanger
If you have to compromise, on which features/extensions
- What can you do without: Either attic conversion or guest-office room
- What you cannot do without: Basement
Why is the design like this? No design yet; we are still considering the orientation on the plot.
It will be a timber frame construction, a gable roof to fit well, knee wall about 1.3m (4.3 ft), roof pitch >45°. The current roof is 60° and gives it a rustic fairy-tale look. On the south side, we want nearly full photovoltaic coverage except for a few roof windows; on the north side, we can imagine a dormer also to integrate the staircase to the attic—maybe a cross-gable?
The rough idea is close to the volume of a Danwood Point 138.1, but a bit wider and longer, and “narrower at the front” (the east side facing the street) due to the tree. Plus an attic conversion with a steeper roof. Access via staircase on the north side.
Alternatively, separate accessory apartment in the south and main residence in the north, but that would split the already narrow house into even narrower parts.
We would like a local timber frame general contractor (any recommendations in the greater Hamburg area?).
Am I completely off track? Have I forgotten anything? Made any major mistakes besides not building three years ago? Are important details missing? Will it all turn out too cramped? Is the budget roughly realistic? Aside from a garden shed, I have no building experience but some electrical knowledge. Photovoltaics and networking could be done by me, full electrical installation I am allowed but would not be practical with a general contractor.
Or is the program so complex that an architect is absolutely necessary because a draftsman would be overwhelmed? From my research it seems that architects for single-family homes that are not villas are quite rare.
Thanks to everyone who made it this far! And even more thanks to those who share their opinions or ideas.
Attached are current ALKIS excerpt, aerial photo, and building plan excerpt, all oriented north and approximately the same section. I hope they are legible… Red borders and points mark the plot.
Currently, my father, my wife, and my child (under 1 year old) live in a small residential house from the 1950s with 61m² (655 sq ft) of living space. The property is owned 50/50 by my father and me but is still partly being paid off by my grandmother (my outstanding payments are held in a separate account and are therefore just a “pass-through” item, while my father pays his monthly installments from his income). The plot is in Hamburg Iserbrook and measures 681m² (7,333 sq ft) with a standard land value of €985.
Unsurprisingly, the space is becoming somewhat tight, even though we get along well. Furthermore, the health of the older housemate is declining, and the narrow staircase to the upper floor is already becoming difficult to manage.
The basic idea is this: I would receive the second half of the plot as a gift, debt-free. My father will continue paying off his installments until he inherits the remainder. In return, we will build him a nice accessory apartment with the corresponding right of residence (or usufruct right, which still needs to be clarified)—barrier-free and compact so he can live independently there for as long as possible. The rest of the ground floor would then only contain a multipurpose room, guest toilet, and hallway; upstairs four rooms and a bathroom. We would like a (simple) converted attic as a retreat area. To relieve the ground floor space and avoid fully using the building envelope (sealing of surfaces, etc.), we plan a basement, as there are also two space-intensive hobbies and a workshop desired for DIY projects. I will also build some of the furniture myself.
Now to the questionnaire:
Building Plan / Restrictions
Plot size: 681m² (7,333 sq ft) with existing house
Slope: No, but the area from the street level up to the terrace is filled +90cm (35 inches), the garage is at about +40cm (16 inches), the neighboring plot to the north also about +40cm (16 inches), and to the south approximately at street level
Floor area ratio (FAR): 0.4
Plot ratio (building coverage ratio): 0.4
Building envelope, building line, and boundaries: 5m (16.4 ft) setback to the street, then 15m (49.2 ft) deep, 2.5m (8.2 ft) setback on each side (more for taller buildings)
Edge development: Allowed (garages etc., max. wall height 3m (10 ft), max. length 9m (30 ft))
Number of parking spaces: We believe none are legally required; we plan to provide one for future use, for electric vehicle charging (currently not needed)
Number of floors: One full story; ALKIS shows some buildings apparently with two floors (see attachment)
Roof type: Not specified
Architectural style: Not specified
Orientation: Not specified
Maximum heights/limits: Not specified
Other requirements: No illuminated advertising signs 😉
The 1965 building plan mainly mandates “residential zoning only” and “one full story,” but even these rules seem flexible. There is a very large copper beech tree in the southeast corner of the plot, with an estimated crown diameter of 10m (33 ft) and at least 12-14m (39-46 ft) tall. The tree is to be preserved (it is unclear if it must officially be preserved with a new build). I expect that the new building must not come closer to the tree than the current building—about 2.5m (8.2 ft) from the trunk. The trunk itself is roughly 1.5m (5 ft) in diameter. A pruning plan is under discussion (also due to shading of the roof, planned for solar panels).
Owners' Requirements
Architectural style, roof shape, building type: Detached single-family home, gable roof with pitch >45°, rather long and narrow
Basement, number of floors: Yes to basement, 1.5 floors plus a converted attic
Number of occupants, ages: 4 (64 (gruff and private), 34, 31, under 1) Another child should be possible
Ground floor space needs: Open-plan area preferably with a small pantry, guest toilet
Accessory apartment with barrier-free design (walk-in shower, open living kitchen with sleeping niche). Can be small.
Shared hallway important (for potential care needs without going outside, access to joint basement with laundry facilities, etc.)
Upper floor space needs: 1 bedroom with a large bed and built-in closets but no extras, 3 rooms (1 child’s room, 1 office/child’s room, 1 guest/office (can be small)), 1 bathroom with a larger vanity, bathtub, and shower
Attic space needs: 2 “retreat” areas for the adults; if necessary, just a rocking chair with reading lamp and sewing machine on one side, and a gaming PC on the other. The current attic is an equilateral triangle with 2.1m (83 inches) side length; it doesn’t need to be much larger/wider/higher than that.
Basement space needs (access via shared hallway + additional exterior entrance): Technical room with heat pump, ventilation, electrical distribution, inverter, server; woodwork workshop; laundry room; 2 hobby cellars for large-format collections—Lego and beer cans, no kink-shaming please 😉 ; 1 storage room for decorations, suitcases, camping gear, etc. Must be heated (and ventilated), but simple tile flooring and surface-mounted installations are sufficient.
Office: Family use or home office? Home office about three times a week, plus one self-employed side business
Guest stays per year: 6–10, usually just one night, sometimes 2–3 nights
Open or closed design: Open on the ground floor but staircase not located in the living room/open space
Conservative or modern construction? I’m never quite sure of the difference, but I feel fully modern
Open kitchen, kitchen island: Yes, cooking often and joyfully, also with guests
Number of dining seats: 6; existing table extends to 14 seats for Christmas and birthdays
Fireplace: No, no chimney planned
Music/stereo wall: No
Balcony, roof terrace: No
Garage, carport: Carport/roof overhang directly at the building would be good, mainly for bikes and potentially for an electric vehicle in the (near) future. To my knowledge, Hamburg does not require parking spaces.
Vegetable garden, greenhouse: Maybe a small bed later, but not important at the moment
Other wishes/particularities/daily routine, including reasons for certain choices: Currently, leisure activities happen at the dining table, which is between sofa and TV (used about once a week), so large lounge furniture is not really needed. The tree is a critical factor, as it likely narrows the building envelope in the front area to about 6.5m (21 ft). We don’t want to move the house further back because of the garden.
House Design
Planner: Still in the very early idea phase. Overall, we think about 180m² (1,937 sq ft) of living space plus basement. We currently live as four on 61m² (655 sq ft) and can manage. We don’t need huge increases in room size, rather a spatial separation with the accessory apartment and space for hobbies and home office. Dressing rooms or a children’s bathroom are not planned.
Personal budget limit for house including fittings: €750,000–800,000 (USD amount varies), with much furniture available from the existing house. Demolition cost would be extra, but I see plenty of grants and rental expenses during construction period. €450,000 (about $480,000) equity is available; the plot described above would be fully paid off (worth almost €700,000 or approximately $750,000).
Preferred heating technology: Ground-source heat pump with deep borehole and 12–15kWp photovoltaic system plus centralized controlled residential ventilation with enthalpy heat exchanger
If you have to compromise, on which features/extensions
- What can you do without: Either attic conversion or guest-office room
- What you cannot do without: Basement
Why is the design like this? No design yet; we are still considering the orientation on the plot.
It will be a timber frame construction, a gable roof to fit well, knee wall about 1.3m (4.3 ft), roof pitch >45°. The current roof is 60° and gives it a rustic fairy-tale look. On the south side, we want nearly full photovoltaic coverage except for a few roof windows; on the north side, we can imagine a dormer also to integrate the staircase to the attic—maybe a cross-gable?
The rough idea is close to the volume of a Danwood Point 138.1, but a bit wider and longer, and “narrower at the front” (the east side facing the street) due to the tree. Plus an attic conversion with a steeper roof. Access via staircase on the north side.
Alternatively, separate accessory apartment in the south and main residence in the north, but that would split the already narrow house into even narrower parts.
We would like a local timber frame general contractor (any recommendations in the greater Hamburg area?).
Am I completely off track? Have I forgotten anything? Made any major mistakes besides not building three years ago? Are important details missing? Will it all turn out too cramped? Is the budget roughly realistic? Aside from a garden shed, I have no building experience but some electrical knowledge. Photovoltaics and networking could be done by me, full electrical installation I am allowed but would not be practical with a general contractor.
Or is the program so complex that an architect is absolutely necessary because a draftsman would be overwhelmed? From my research it seems that architects for single-family homes that are not villas are quite rare.
Thanks to everyone who made it this far! And even more thanks to those who share their opinions or ideas.
Attached are current ALKIS excerpt, aerial photo, and building plan excerpt, all oriented north and approximately the same section. I hope they are legible… Red borders and points mark the plot.
B
BucheOnBoard30 Mar 2023 22:24So, things always take a bit longer than expected, but I have incorporated many of @K a t j a’s ideas—although so far I’ve only managed the ground floor. Mainly, the house is still a bit smaller (13m x 8.5m (43ft x 28ft)), which you can definitely notice, as there are still some tight spots here and there. But this is just a first draft for us to better weigh our wishes and needs. Since I can't go beyond a knee wall height of 1.3m (4.3ft) on the roof slope (unless exceptions from the building permit / planning permission are granted), the attic remains quite cramped. However, I think the upper floor works well enough. Maybe, as @K a t j a suggested, we will skip the attic and instead have one more room on the upper floor—but I’ll think about that more tomorrow.
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BucheOnBoard6 Apr 2023 11:43I have now sketched the upper and attic floors as well – with the staircase position, there is logically no height issue on the upper floor, and in the attic, you would get two cozy rooms. However, above the stairs, you would definitely need a roof window. I also exported a cross-section and a 3D view – since I’m not allowed to draw sloped walls in the roof area (wrong module in the software), some elements stick out of the roof surface, so please ignore those.
The furnishing is still quite generous; we probably won’t need that many closets on the upper floor, and I haven’t looked into the bathroom details yet.
Despite all this – any concerns, comments, suggestions? After Easter, we plan to take this textual form of the drawings to some house-building companies...
The furnishing is still quite generous; we probably won’t need that many closets on the upper floor, and I haven’t looked into the bathroom details yet.
Despite all this – any concerns, comments, suggestions? After Easter, we plan to take this textual form of the drawings to some house-building companies...
B
BucheOnBoard17 Oct 2023 22:21I’m checking in again, as quite a bit has happened. The soil survey revealed a lot of peat and a very high groundwater level, which makes the basement uncomfortably expensive. We received two estimates totaling more than 200,000 for it, and that would only cover the unfinished basement shell. Therefore, we decided to forego the basement and instead included the utility room in the ground floor layout. The attic will now be used more as storage space rather than a workspace. We have now received a design based on this, which I would like to share here for discussion – we like the basic room layout, but it would be good to make the ground floor slightly smaller to create a bit more distance from the beech tree to the southeast. Otherwise, we have noticed the following so far (no claim to completeness):
- Swap the guest toilet and wardrobe in the main apartment, and reverse the door swing to the main corridor
- Move the wall between the secondary apartment bathroom and the utility kitchen slightly east to gain more space around the dining table
- Omit the north-facing window in the utility room
- Remove the partition wall between the “sleeping” and “living” areas in the secondary apartment, and instead create a flexible room divider with shelving or a cupboard as needed
Otherwise, I think we are not dissatisfied, but this is just the first draft and we have never built a house before. Therefore, I hope to get some good ideas and advice here. All further information can be found in the first post.
Thank you very much in advance!
- Swap the guest toilet and wardrobe in the main apartment, and reverse the door swing to the main corridor
- Move the wall between the secondary apartment bathroom and the utility kitchen slightly east to gain more space around the dining table
- Omit the north-facing window in the utility room
- Remove the partition wall between the “sleeping” and “living” areas in the secondary apartment, and instead create a flexible room divider with shelving or a cupboard as needed
Otherwise, I think we are not dissatisfied, but this is just the first draft and we have never built a house before. Therefore, I hope to get some good ideas and advice here. All further information can be found in the first post.
Thank you very much in advance!
H
hanghaus202318 Oct 2023 10:22Possibly arrange the bathroom like this:
Then it might be possible to move the wall on the east side by 50 cm (20 inches).
Then it might be possible to move the wall on the east side by 50 cm (20 inches).
BucheOnBoard schrieb:
We have received two estimates of over 200,000 for this, and that would only cover the basement as a shell. Wow! 😱
BucheOnBoard schrieb:
We like the basic room layout, It’s also roughly what you drew in #17, except the staircase now has a better location.
BucheOnBoard schrieb:
but this is just the first draft and we haven’t built a house before... Has the architect considered all options allowed by Hamburg’s building regulations?
Especially since the room layout is already quite similar, I get the feeling he more or less copied it.
Regarding the problem with the bedroom and the lack of space for a wardrobe, unless a better idea for the staircase or the overall design suddenly emerges (because the door position essentially takes up your wardrobe space in the bedroom), I would suggest placing the wardrobe under the sloping ceiling using a DIY or carpenter-made solution — basically a 90cm (35 inches) deep sliding door cabinet towards the front, and moving the bed closer to the door.
At second glance, it seemed a bit tight down there to me — I meant the open living area, not the elderly gentleman’s bedroom.
You mentioned you currently live together in 61sqm (655 sq ft)... so the 36sqm (388 sq ft) will probably feel like a palace to you.
However, I might consider building it so that later, if your father moves into a care facility or unexpectedly has a ‘second spring’ (how old is he?), the living area can be opened up to the granny flat. In that case, I would remove the bathroom from the center of the house and swap the kitchen and pantry of the main apartment with the living area so that you can extend the living room later. Maybe I can make a sketch later (bathroom for the granny flat near the utility room, wardrobe facing the hallway, toilet becomes the pantry, etc. — I’m writing this without the plans in front of me), but I can imagine more flexible options this way than having technical rooms in the middle of the house restricting you.
Personally, I also prefer if the kitchen is next to the terrace.
Otherwise, it’s good that you are making the most of the roof pitch.
It’s hard to say more at this point, since the room dimensions are not easy to grasp.
ypg schrieb:
My second impression was personally "quite tight down there," referring to the open-plan living area, not the old gentleman’s bedroom.
You mentioned that you currently live together in 61sqm (650 sq ft)… so the 36sqm (390 sq ft) will probably feel like a palace to you.
However, I might consider designing it so that later, if Dad moves into care or gets a second wind (how old is Dad?), the living area can be opened up to the granny flat. The narrow, cramped open-plan area immediately caught my eye and would be a dealbreaker for the design. Also, you always have to go through the kitchen to reach the living room, which isn’t ideal. Sorry, but waiting for Dad to move into a care home wouldn’t be an option for me.
The separate hallway in the granny flat is, in my opinion, wasted space. Altogether, there are 20sqm (215 sq ft) of hallway on the ground floor—that’s quite a lot. The central staircase position stops the living room from feeling spacious and open. You’d want to open up the hallway, but that conflicts with the cloakroom and the WC. You’re paying a lot of money for this narrow, corridor-like living room—think it over carefully! A swivel TV—that’s like in a hotel—creepy.
The idea of accessing the floor with a simultaneous setback on the upper floor should definitely be questioned. Is there a specific reason related to the one-story appearance, or was it just randomly drawn somewhere? Who’s supposed to keep sweeping the leaves off that setback all the time? Or is there going to be a green roof?
Making the ground floor even smaller is an absurd idea. Now the utility room has also been squeezed in down there. How is that supposed to work?
Maybe it’s better to give up the attic peak and instead build out the entire ground floor with a more favorable staircase location.
What are the current exterior dimensions anyway? 13 x 9 meters (43 x 30 feet)?
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