Renovation and floor plan design - Existing building construction year 86

Hello everyone,
we are currently facing the purchase of a detached single-family house in a quiet family residential area. In addition, renovation and redesign are naturally a special challenge to create an open family living concept, which should temporarily allow rental of the upper floor or use as a holiday apartment for about 5 years.

The most important aspect here is the balance between practical and modern open design on the ground floor as well as on the upper floor; on the ground floor this is already partly achieved by the open extension. On the other hand, the attic presents us with great challenges, which should be solved by the installation of dormers (would raising the roof be an option) in order to gain living space there as well. Unfortunately, at the time of construction no knee wall was built and the slopes heavily press on the rooms.
Currently, there is underfloor heating in the extension, which should be supplemented throughout the entire living area except in the bathroom already renovated in 2015.

The basement is to be used functionally and there is initially no need for adaptation; the oil heating installed here in 1986 is to be replaced in the future by a heat pump.

We look forward to your feedback and valuable ideas for the design, as we are afraid of overlooking something important that could have been done significantly better.

Attached:
- Floor plans: Basement, Ground floor, Attic
- Pictures Ground floor
- Pictures Attic
- Next post Front view and rear view as well as planning.

Best regards

------------------------
Detached single-family house built in 1986; extension built in 2003.
Year of construction / completion: approx. 1986
Development: fully developed
Basement: fully basemented
Condition: partly in need of renovation.
Construction type: solid construction, 30cm KLB insulation stone
Roof shape: gable roof; 18cm between rafters; large roof overhang
Roof: fully converted
Window type: double-glazed plastic/insulating glass
Final energy demand: approx. 100.0 kWh/(m²a); 67,000 kWh in 5 years according to consumption certificate
Energy certificate class: C
Heating: oil heating, fireplace
Total living area: approx. 177 m²
Plot size: 630 m²

Development plan/restrictions
Plot size: 630m²
Number of parking spaces: according to "need", currently 2 (parking space and garage)
Number of floors: 1.5; knee wall 0cm
Roof shape: gable roof, between 20-40 degrees, currently 37 degrees.
Maximum heights/limits
- Eaves height max 6m
Further specifications
- Dormers max 1.4m above the roof
- Dormers max 2/3 of the length of the eaves

=> According to the owner, only 1.5 floors were allowed at the time of construction.
=> Architect is currently examining the feasibility of dormers exceeding 2/3 and 1.4m
=> Aim is exemption from the development plan, analogous to the neighbor, who raised to a 2nd floor.

Requirements of the builders
Style: modern
Basement: utility room, storage, laundry, hobby room
Number of persons: 2 persons, 31 & 30; children planned in approx. 2 years
Ground floor: communal areas open, bright and friendly.
Attic: rental and later owner use, sleeping.
1x office for home office
Open kitchen + cooking island
Number of dining seats: 4-6
Fireplace: yes
Garage, carport: 1x available
- Conversion of the house into 2 residential units for rental purposes for approx. 5 years.

House design
Planning: conversion as a draft planning together with architect.
What is liked particularly: large living area and extension.
What is disliked: roof slopes in upper floor; size of the hallway; no double garage.

Price estimate according to architect/planner: no offer so far.
Personal price limit for conversion: approx. €150,000.
Preferred heating technology: future heat pump

If you had to forgo, which details/upgrades
- can you forgo: attic
- cannot forgo: lots of light, underfloor heating

#2
-Front+rear view
-Design dormers front; the back should also have a dormer on one side.
-Ground floor plan: right side including partition
-Upper floor plan: looks very "crammed" in the hallway...

Temporarily renting out the upper floor and using it yourself in 5 years excludes a suitable conversion that allows you in 5 years a (reasonable and practical) sole use as a single-family house.

Move in, live for five years, and then "properly" renovate.

Temporarily renting on the upper floor and using it yourself in 5 years excludes a suitable conversion

Could you please elaborate on what bothers you about this? Do you see fundamental changes in the floor plan if it were to be used privately immediately?

Perhaps a few additions from us regarding the current situation:
We currently live in my 95sqm condominium; the monthly costs are 800€ loan payments. Therefore, the move would be quite flexible to plan, and the double burden is manageable.
The cost for the property is 510,000€, with a land value of about 400€/sqm.

Additionally, our considerations regarding renting:
-The rent for such an apartment is about 600€ cold, so for 5 years approx. 36,000€ gross rental income and savings on additional costs.
-The partition is done by ourselves using drywall construction so that a reversal can be done easily.
-We are aware that the transition phase represents a certain compromise regarding living comfort.

A look at the renovation measures
a) that must be done for personal reasons:
- Installation of underfloor heating + floor coverings
- New kitchen in the open living area
- General renovations: interior walls, door replacements, etc

b) In addition nice to have:
- Window replacement + front door
- Expansion of dormers or other options
- Roof slope insulation
- WLP
- Basement ceiling insulation

Some of a) overlaps with b) to avoid double work...

I would be very grateful for further suggestions, especially on how you would plan the attic expansion or the overall floor plan. Any idea is very valuable as an alternative perspective.

Two fully equipped bathrooms upstairs and downstairs including water supply/drainage.
Double electrical installations
Truly separate entrance areas
Kitchens upstairs and downstairs with electricity and water
Plan heating for two apartments (including double hot water)
Building permit for a two-family house
Parking spaces for two apartments
Etc.

And then you rebuild everything in five years so that it looks and functions as a single-family house?

You can't get that much rent to cover all of that.

Therefore, either rent out permanently or renovate directly as a proper single-family house.

And then in five years you rebuild everything so that it looks and functions like a single-family house?
You can’t get that much rent to pay for all of that.

I see the concerns about the additional costs, but are the costs really that much higher?
In both variants, I would probably execute most things exactly as you described regarding the separation of electrical & water on the ground floor and upper floor.
We plan to move up later with the parents + children’s room and would like to have a nice bathroom here with a bathtub etc.; a fully equipped bathroom would not be a luxury for us but rather a standard. Currently, without a child, an office downstairs and a small master bedroom suffice for us – something like a walk-in closet is not a must for us.

Building permit + parking spaces is a topic with question marks, I agree.
__

Let’s put aside the meaningfulness for a moment.

How would you plan the ground floor in the living area, especially where should the kitchen go? And would you perhaps also remove the wall between the living room + parents’ room to create a larger area here?
The whole area is 53 sqm without breaking through the wall and approximately 70 sqm with it. The variant without breaking through the wall seems difficult for placing the kitchen, as a large kitchen island is desired by the lady. The gray on the wall would be the middle fireplace.
Only the horizontal wall is load-bearing; everything else are 11.5 cm walls.