Renovation of Single-Family House: Idea Generation

Hello everyone,

My girlfriend (no children yet) and I are currently facing the decision to take over her grandmother’s house, renovate it, and then live in it. At the moment, we have many thoughts but find it difficult to assess what can be implemented and what is economically sensible in the end. I want to use this post to gather ideas...

About the house: It is a detached single-family house built in 1965, solid construction. According to an expert report, the condition is good. The roof was completely redone and insulated a few years ago after a severe hailstorm (unfortunately, we do not know how well the insulation was done). Also, some windows have already been replaced. The heating system (oil) is still okay for now, but it will surely have to be replaced at some point. However, a gas connection is already installed in the basement. There is also a wall in the basement that is slightly damp, which is presumably due to the missing external drainage.

Attached you will find the floor plans of the basement and the ground floor. The attic is already developed but very simple.

So, here come the questions:

1.) What should be done immediately in a house like this? We assume that at least the remaining windows, complete electrical wiring, all floors, partly the ceilings, the bathroom including the guest toilet, the kitchen, the front door, and the missing drainage will have to be done immediately. We are unsure about the interior doors, the heating system, all the piping for heating and water/sewage, and the exterior insulation. What must/should be done immediately here? If the pipes need to be replaced, it would probably be best to do it at once. But is it necessary?

2.) Room layout: We have several things on the ground floor that we don’t like as they are. For example, the bathroom is too small and has no toilet. The question here is how to use the space of the adjacent room (which is actually not a separate room but rather a hallway) for that purpose? Furthermore, we don’t like the separation between the dining room and living room by load-bearing wall sections and would like to remove them, possibly including the piece of hallway, to gain space. The large hallway is wasted living area for us. What can be done here and how complex is it?

4.) We are fairly sure that we won’t get any further without an architect. Although I am probably skilled in craftsmanship, I am inexperienced and also limited time-wise due to a full-time job ;) Do you also think that hiring an architect makes sense here? Does anyone happen to know a competent partner in the Reutlingen area?

I know these are many questions and probably some background information is missing. Nonetheless, I am very grateful for any tips/advice/experience reports.

Best regards
Michael

That sounds like a complete renovation. Except for the heating and interior doors, almost everything is being done. Get an expert for that. Ideally an architect who plans and obtains quotes and a civil engineer who supervises. And for the openings, you might need a structural engineer. Evaluating this here in the forum goes too far and is not possible this way. But this won't be an inexpensive pleasure. We have just been through it and it costs a lot of money and nerves :-) But in the end, it's worth it.

Our experience: Definitely work with an architect who has experience with building on existing structures/ renovation. Look at reference projects. Then go through everything with him, listen to his first opinion, and then see if it can work together.

My recommendation: Arrange a first on-site appointment with the aforementioned architect experienced in old buildings and renovations, during which he inspects the building’s condition, notes any construction defects, assesses the building and planning law situation of the property, and discusses your remodeling and repurposing ideas with you.
A building permit will certainly be required for the renovation if the structural interventions become more extensive: relocating/demolishing load-bearing walls, ceiling openings, wall openings for new or larger doors/windows. If the roof is to be converted, this would be a building permit-required change of use. All building services including piping will likely need to be renewed. Previously carried out "renovations" (roof insulation) must be critically reviewed by the architect. They are usually not professionally executed. Quick fixes in the sense of "basement waterproofing" through drainage are to be avoided. It is mostly condensation moisture.
Regarding the approach: Once you and the architect have agreed, a dimensional and substantial building survey should be conducted and current as-built plans created. This is a very important basis. If this fundamental analysis is done carelessly to save, for example, planning costs, it will backfire later during the renovation in the form of surprises that have time and financial impacts. On this basis, the architect prepares a preliminary draft/a design, each with a cost estimate, with which you can plan your financing. The architect aligns your financial possibilities with his planning, or reconciles wish and reality. Sometimes/mostly with compromises to the original vision.
Own contributions can be considered in the calculation but should be realistically assessed and not overestimated. Realistic are, for example, 8-10% of the gross construction costs, which also means 20-25 weekly hours/man-hours of effort and must be continuously provided. Recommended, for example, during demolition, as far as permissible and sensible.
Overall, after the preliminary draft and the first cost estimate, it should become clear whether the renovation and the refurbishment/energetic refurbishment are worthwhile. If the costs approach those of a comparably sized new building – approximately gross € 1,500/m2 net usable area (cost groups 300+400), excluding ancillary construction costs (cost group 700), outdoor facilities (cost group 500), and equipment/furnishing (cost group 600) according to DIN 276 – then it is generally no longer sensible. Unless the house has great design value and a very good location (standard land value) and could fetch at least this price on the market after renovation. Banks will see it this way for financing as well.