Floor plan and extension of a house - Year built 1966

Our house is to be completely renovated and extended upwards. The house will largely reuse the existing walls for the renovation.

For the complete renovation, all walls will be removed up to the new window sill height, then a ring beam will be placed, and on top of that, the extension will be built using timber panel construction. The existing clinker brick walls will be insulated with wood wool and will receive a curtain facade made of steel sheet standing seam (is this cheaper than zinc sheet?). The goal is KFW 55 or better. The floor on the ground floor will be insulated and will have underfloor heating. The staircase in the basement will be extended by one step, so about 25 cm height is available for this. In the attic, the sloping roof areas are suitable for wall heating. The children's rooms have a gallery accessible by a ladder. They can only be accessed via the ground floor. The parents’ area is thus more private, and possibly the house can be divided into two residential units in the distant future. The living/dining area is compact. The front door should be made of glass so that we can enjoy the evening sun (currently there are no windows on the west side, and that is often a shame). The entrance is far enough from the street so that this should not be a problem.

Basically, we also wondered whether a new build would be more sensible. For now, I tend rather towards renovation. Construction is planned earliest in 2025. We are not in a hurry since the children are still small and we manage well with our space.

(The site plan is oriented to north)

Development Plan/Restrictions
Size of the plot - 1040 m²
Slope – slight, approx. 1.50 m gradient
Site coverage ratio – 0.25
Floor area ratio – 0.4
Number of stories - 1.5
Roof shape - free
Style - free
Orientation – existing building

Client Requirements
Style, roof shape, building type – renovation and upward extension of the existing building
Basement, stories – half basement, 1.5 stories
Number of persons, age - 2+2 (4 & 2)
Space required on ground floor, upper floor – GF: 85 m² UF: 55 m²
Office: family use or home office? – full-time home office and one part-time
Overnight guests per year - few
Open or closed architecture – open living space
Conservative or modern construction – modern
Open kitchen, kitchen island – yes, yes
Number of dining seats – 4-6
Garage, carport – present
Utility garden, greenhouse – maybe later
Large cistern with rainwater use in the house
Central controlled residential ventilation – since some neighbors like to use their fireplaces, plus the other advantages of controlled residential ventilation
Photovoltaics completely on north and south roofs
The basement must be newly insulated
Clay plaster for interior finishing

House Design
Who is responsible for planning: me
What do you particularly like? Why? The house remains compact due to the upward extension
What do you not like? Why? – Everything is okay so far
Price estimate according to architect/planner: - no offers obtained yet
Personal price limit for the house, including equipment: 400k, less would be better
Preferred heating technology: - heat pump with horizontal trench collector

If you have to do without, which details/extensions
-can you do without:
-can you not do without:

Why did the design become what it is now? e.g.
- based on the interior walls of the old house
- we switched from an extension to an upward extension because it is cheaper. The view from the master bedroom is now also much nicer than it would have been with an extension

What is the most important/basic question about the floor plan in 130 characters?

Do you see a problem I might have overlooked? Your opinion is usually very direct, but always helpful :-)

Completely without a cloakroom? Where do shoes, jackets, bags, schoolbags go? The entrance area looks like a showroom, not a residential house. I would describe the rest as unconventional but exciting. However, I would give some more in-depth thought to how usability will look over the next X years. I would not build like this.

This is actually not a renovation, but a completely new house, just with the old exterior walls on the ground floor. In the new open space, you will first have to figure out how to handle the structural aspects. Budget-wise, I am conflicted because you are actually doing EVERYTHING new.

What I like are the two-story children's rooms. Access to the upper part should be via a furniture staircase, not as planned by a ladder. Especially not if sleeping takes place upstairs and the children are still small. It also makes vacuuming upstairs easier.

The non-existent entrance area and missing wardrobe fit more with a small holiday home than with a single-family house.

So completely without a cloakroom? Where do shoes, jackets, bags, school satchels go?

Next to the entrance is a floor-to-ceiling cupboard and the shoes go into the bench next to it. That then provides much more space for jackets and shoes than we have now. So for us, a great improvement.

I did not attach a measured floor plan. In the ground floor plan, there are pink squares that are 1m x 1m in size.

The stairs and the entrance do not work. 16 steps at 26cm each amount to 3.9 m running length

Are there any dimensions as well?

Plan of the basement?

If you are planning yourself, please do it properly. The demolition is shown with yellow dashed lines and the new construction in red. The original parts remain black.

I only know the entrance that leads directly into the living room from North America.

70 cm exterior walls on the ground floor?

Standing seam is a very expensive facade and roof covering.

A roof with many roof windows and photovoltaics do not get along well.

The bedroom window should have good shading. That is also very expensive.

The house is relatively large. There is definitely room for better planning.

The bathtub directly next to the knee wall? How does one get in there?

The floor area 9.5*13 = 123.5 m2 * 2 * 2,400 euros = 592,800 euros + 10% for miscellaneous. We are talking about 650 k here.

Are there images and plans of the existing condition?