ᐅ Single-family home with a granny flat on a 450 sqm sloped lot
Created on: 9 Feb 2022 11:44
K
Kristijan
Hello everyone,
Until now, I have only been a silent reader here, but I would like to present our own house concept for discussion. I am hoping for candid criticism, as well as your ideas and suggestions.
We are a blended family with four children (three are usually at home) and we are planning to build a single-family house with a secondary apartment in NRW. At the beginning of last year, we bought a sloped lot in a typical new development area and have since worked with an architect to develop a house concept. We designed a very simple building form (four walls and a roof) with an efficient floor plan. We sent our plans to several prefabricated house companies, asking for cost estimates, hoping that our budget might allow for potential expansion of the house. Now, faced with their offers, we have to admit that even our smallest possible floor plan exceeds our budget. The budget is about 550,000 euros for the house including additional construction costs (excluding the land). With the secondary apartment, we had hoped to double the KfW funding in the KfW 40 EE class with 67,500 euros to increase the budget. But it is what it is.
Perhaps our preliminary cost estimate was a bit naive. In any case, we are currently reconsidering the concept and are considering doing without a basement.
And now, please, fire away with your frank criticism and unvarnished truths. 🙂
Zoning Plan / Restrictions
Plot size: 450 sqm (4,844 sq ft)
Slope: Yes, north-facing slope (from the street toward south-southwest) with about 1.5 m (5 feet) elevation within the building envelope (1 meter (3 feet) within the planned footprint) rising
Floor area ratio (FAR): ?
The zoning plan does not provide this information
Building area ratio (site coverage): 0.4
Building envelope, building line and boundary: 19.5 m (64 feet) wide (street side), at the rear 17 m (56 feet) wide and 14 m (46 feet) deep
Edge development: Yes
Number of parking spaces: 2 for the main unit and 1 for the secondary apartment
Number of floors: 2.5
Roof type: Gable roof
Architectural style: Traditional
Orientation: Ridge runs from west-northwest to east-southeast
Maximum heights / limits: Maximum ridge height 9.5 m (31 feet) above finished ground floor level (this may exceed the reference street level by max. 0.5 m (1.5 feet))
Other requirements: Side setbacks 3 m (10 feet), setback from the street 3.5 m (11.5 feet)
Client Requirements
Architectural style and building type: Simple, economical building form with a gable roof
Basement, floors: Basement with secondary apartment, total 2.5 floors
Number of people, ages: Household of 5-6 people: parents aged 38 and 36, four children aged 7, 4, 2x 2 years. Family planning went a bit beyond the target and is now complete 🙂 plus grandmother in the basement apartment
Space needs on ground / upper floors: About 140-150 sqm (1,500-1,615 sq ft): kitchen, living room, 1 bedroom, 3 children’s bedrooms, 1 guest/office/patchwork room, 2 bathrooms
Utility room in the basement
Office: 1 flexible room required
Guests per year: About 10
Open or closed layout: Form follows function
Conservative or modern style: Hm, what exactly is meant here?
Open kitchen, kitchen island: Open kitchen adjacent to dining area (a kitchen island is welcome here), but closed off toward the living room
Number of dining seats: 6-8
Fireplace: No
Music / stereo wall: TV in the living room
Balcony, roof terrace: Covered terrace facing the garden with pass-through window from the kitchen
Garage, carport: Carport with green roof and additional storage space would be ideal
Vegetable garden, greenhouse: Small kitchen garden along the property boundary
House Design
Designer: Independent architect working with a prefabricated house company and DIY elements
What do you particularly like? Efficient use of space. Despite compactness, all requirements regarding space needs, especially number of rooms, are met
What do you dislike? Especially the ground floor could be more generous, the basement or storage spaces could be larger
Price estimate (according to architect): Not available
Price limit including fittings: 550,000 euros plus KfW funding if still available
Preferred heating system: Air-to-water heat pump
If you have to sacrifice something, which details or extensions would you give up?
-can give up: Reluctantly on the separate parents’ area
The secondary apartment is also under discussion
The sliding doors on the ground floor are due to a coordination error and can be removed
-can not give up: Number of rooms
Why did the design turn out the way it is?
We basically created the design ourselves. The architect later made some optimizations. Our main focus was to accommodate all room requirements within a compact floor plan on a small plot. Furthermore, as parents of four children, we wanted our own small private space.
What is the most important / fundamental question about the floor plan, summarized in 130 characters?
Is our house concept failing due to our budget expectations? What would you do differently and why?
Until now, I have only been a silent reader here, but I would like to present our own house concept for discussion. I am hoping for candid criticism, as well as your ideas and suggestions.
We are a blended family with four children (three are usually at home) and we are planning to build a single-family house with a secondary apartment in NRW. At the beginning of last year, we bought a sloped lot in a typical new development area and have since worked with an architect to develop a house concept. We designed a very simple building form (four walls and a roof) with an efficient floor plan. We sent our plans to several prefabricated house companies, asking for cost estimates, hoping that our budget might allow for potential expansion of the house. Now, faced with their offers, we have to admit that even our smallest possible floor plan exceeds our budget. The budget is about 550,000 euros for the house including additional construction costs (excluding the land). With the secondary apartment, we had hoped to double the KfW funding in the KfW 40 EE class with 67,500 euros to increase the budget. But it is what it is.
Perhaps our preliminary cost estimate was a bit naive. In any case, we are currently reconsidering the concept and are considering doing without a basement.
And now, please, fire away with your frank criticism and unvarnished truths. 🙂
Zoning Plan / Restrictions
Plot size: 450 sqm (4,844 sq ft)
Slope: Yes, north-facing slope (from the street toward south-southwest) with about 1.5 m (5 feet) elevation within the building envelope (1 meter (3 feet) within the planned footprint) rising
Floor area ratio (FAR): ?
The zoning plan does not provide this information
Building area ratio (site coverage): 0.4
Building envelope, building line and boundary: 19.5 m (64 feet) wide (street side), at the rear 17 m (56 feet) wide and 14 m (46 feet) deep
Edge development: Yes
Number of parking spaces: 2 for the main unit and 1 for the secondary apartment
Number of floors: 2.5
Roof type: Gable roof
Architectural style: Traditional
Orientation: Ridge runs from west-northwest to east-southeast
Maximum heights / limits: Maximum ridge height 9.5 m (31 feet) above finished ground floor level (this may exceed the reference street level by max. 0.5 m (1.5 feet))
Other requirements: Side setbacks 3 m (10 feet), setback from the street 3.5 m (11.5 feet)
Client Requirements
Architectural style and building type: Simple, economical building form with a gable roof
Basement, floors: Basement with secondary apartment, total 2.5 floors
Number of people, ages: Household of 5-6 people: parents aged 38 and 36, four children aged 7, 4, 2x 2 years. Family planning went a bit beyond the target and is now complete 🙂 plus grandmother in the basement apartment
Space needs on ground / upper floors: About 140-150 sqm (1,500-1,615 sq ft): kitchen, living room, 1 bedroom, 3 children’s bedrooms, 1 guest/office/patchwork room, 2 bathrooms
Utility room in the basement
Office: 1 flexible room required
Guests per year: About 10
Open or closed layout: Form follows function
Conservative or modern style: Hm, what exactly is meant here?
Open kitchen, kitchen island: Open kitchen adjacent to dining area (a kitchen island is welcome here), but closed off toward the living room
Number of dining seats: 6-8
Fireplace: No
Music / stereo wall: TV in the living room
Balcony, roof terrace: Covered terrace facing the garden with pass-through window from the kitchen
Garage, carport: Carport with green roof and additional storage space would be ideal
Vegetable garden, greenhouse: Small kitchen garden along the property boundary
House Design
Designer: Independent architect working with a prefabricated house company and DIY elements
What do you particularly like? Efficient use of space. Despite compactness, all requirements regarding space needs, especially number of rooms, are met
What do you dislike? Especially the ground floor could be more generous, the basement or storage spaces could be larger
Price estimate (according to architect): Not available
Price limit including fittings: 550,000 euros plus KfW funding if still available
Preferred heating system: Air-to-water heat pump
If you have to sacrifice something, which details or extensions would you give up?
-can give up: Reluctantly on the separate parents’ area
The secondary apartment is also under discussion
The sliding doors on the ground floor are due to a coordination error and can be removed
-can not give up: Number of rooms
Why did the design turn out the way it is?
We basically created the design ourselves. The architect later made some optimizations. Our main focus was to accommodate all room requirements within a compact floor plan on a small plot. Furthermore, as parents of four children, we wanted our own small private space.
What is the most important / fundamental question about the floor plan, summarized in 130 characters?
Is our house concept failing due to our budget expectations? What would you do differently and why?
K
Kristijan11 Feb 2022 11:18K a t j a schrieb:
What a coincidence – how things come together again… 😉 We are currently living in an old, charming timber-framed house with all the typical features (low ceilings, small window areas, connecting rooms, and high energy consumption). Considering this, the idea of a new build feels like a huge improvement, even under the condition that the floor area won’t actually be larger and ideally we would like one more room.
For the sake of the children’s rooms (currently there are two bedrooms and two playrooms for the kids), we have given up having a living room. We gave up our TV years ago anyway, and watching Netflix on a laptop is sufficient for us at the moment.
This has led us to consider again, in the new house, initially giving up the living room once more in favor of an additional children’s room. This extra room could be placed in the attic if needed.
What do you think about this?
Kristijan schrieb:
This could then be done in the attic if needed.
What do you think about that? Converting the attic would be another major effort and financial expense. After moving in, you will need a lot of money just to make the house livable. In my opinion, nothing much will happen in the first 5 to 10 years. The garden will also need a swing or a barbecue with seating area, curtains, lamps, and so on – the money disappears like butter in the sun. On top of that, you have to pay off the house. So where would the money for the conversion come from? Is a significant increase in income expected in the coming years? If not, then assume the attic will stay as it is. Otherwise, it’s better to build bigger right from the start.
K
Kristijan11 Feb 2022 11:46K a t j a schrieb:
Finishing the attic would be a major effort and a significant financial burden. After moving in, you will need a lot of money just to make the house livable. In my opinion, nothing much will happen in the first 5 to 10 years. The garden will also need a swing or a barbecue with seating, curtains, lights, etc. – the money disappears like butter in the sun. On top of that, you have to pay off the house. So where should the money for the attic conversion come from? Is a substantial increase in income expected in the coming years? If not, then assume the attic will remain as it is. Otherwise, it would be better to build bigger from the start. Okay, since large salary increases are not expected—we work in the public sector, so we can fairly accurately predict our income for the next few years—you’re probably right, and the attic will remain unused.
I thought that if the roof itself, and not the floor ceiling of the upper story, is insulated, and the builder roughly installs partition walls while also adding a large window on one gable end, and later an infrared panel heating system during the finish work, the costs might remain manageable.
Probably wishful thinking again.
Kristijan schrieb:
I thought that if the roof, rather than the ceiling between floors, is insulated and the builder roughly installs interior partition walls, adds a large window on one gable end, and later installs an infrared panel heating system during the finishing phase, the costs might be manageable.
Probably not. If you really plan to do this, it’s worth making some preparations. For example, install empty conduits, a drainage shaft, and cable connections in advance—though honestly, that’s always worth doing. But when you carry out the finishing work yourself, you pay for everything. Every wooden batten, every insulation panel, partition wall, electrical outlet—nothing is free or significantly cheaper in bulk.
Kristijan schrieb:
Actually, the main goal seemed to be selling as many wooden houses as possible. Our basic plan was to build using timber frame construction. To compare costs, I contacted a local general contractor who builds with solid construction. They mentioned a cost of around 3000 euros per square meter (approximately 279 USD per square foot) for a turnkey build. Be careful with the term turnkey. For some, turnkey really means the moving truck can pull up; for others, it means the lockable front door is installed. (Okay, that’s a slight exaggeration, but floor and wall coverings are usually missing.) You also need to carefully check what exactly is included in the price per square meter. The flat rates for floor coverings were so high that we couldn’t find any tiles with additional charges at the tile store; toilets, construction waste removal, etc. were all included, even the insurances. Electrical outlets, light fixtures, and more were included beyond the usual scope of work—and still not enough.
Don’t dismiss solid construction, especially now without a basement and only following energy-saving regulations.
K
Kristijan11 Feb 2022 12:57K a t j a schrieb:
It would be very helpful if the text version of the development plan were also shared, so that we don’t only find out at the end of the thread what is or isn’t allowed.I just converted the development plan, which I previously only had as a PDF, hoping that it is readable now.
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