House purchase, year built 1966 - what to consider?

Hello everyone,

after a long search, I came across a very interesting single-family house that I will be visiting in the next few days. Since the complete construction drawings are also included in the exposé, some questions have arisen from them:

- Fessen ribbed concrete ceiling: Has anyone ever heard of this? What I was able to find out is that the company was from Hanau. I ask especially because I remember that in the 60s there was a ceiling type that sometimes caused extreme problems and even collapsed.

- Cast asphalt instead of screed: I have read partly that this is the higher-quality alternative to cement screed. It is said to have good impact sound insulation and thermal insulation. However, I have also read in this forum that it can contain PAHs, which are said to be carcinogenic, at least when it is worked on. At least partially I would remove the floor coverings: bathroom with small mosaic tiles, hallway and kitchen with the usual 60s PVC tiles. Remaining rooms with strip parquet, which can probably stay.

- Bituminous coating: This was applied to the lower part of the masonry. I remember that this was already advanced at the time and represents a good barrier against moisture.

- Masonry 30 cm bricks: State of the art at the time or already outdated? Seems rather thin to me compared to other houses I have visited.

- Low-pressure oil heating with outdoor temperature sensor: Do low-pressure heating systems really exist? I think this rather means low-temperature heating, if it already existed in the early 90s. Previously there was apparently no oil heating installed in the house.

Thanks in advance for your tips and have a nice weekend, Max

Regarding the ceiling: Maybe you have a chance to learn more about the ceilings if you get the building file and the associated structural engineering from the city.

30 cm masonry can be many things, but back then it must have been standard technology. Just uninsulated by today's standards.

I don't know what a low-pressure oil heating system is, but maybe it means a gravity heating system (which still got a pump retrofitted in the 90s). Are the pipes and radiators still from the 60s?

Also check the state of the electrical system, e.g. whether there are FI switches in the fuse box. Also check the condition of the water and sewage services.

A house from the 60s can become a nice (core) renovation project.

Today I went for the inspection, which clarified some details:

- The heating system is a Viessmann Vitola Biferral, low-temperature boiler with an outdoor temperature sensor. From what I have been able to find so far, there is no obligation to replace this heating system after 30 years. Due to the very solid installation, a replacement is generally advised against as long as everything is working. The oil tanks are from the same year (1990) and are also still in very good condition.

- Water: Pipes are completely copper, downpipes are entirely cast iron. Therefore, I would probably renew the latter completely. The house connection was apparently renewed at some point, as there is a plastic pipe in front of the meter clock. I can hardly imagine plastic from the 1960s.

- Electrical: I think it needs to be renewed, as it dates from 1967. Three-core, but with a red protective conductor. The red protective conductor is said to often cause problems because the insulation becomes brittle due to the red color. There was no RCD anywhere. However, it was noticeable that for the year of construction there were already relatively many outlets - so it probably is not the worst installation.

- Windows: Completely single-glazed. Here, I would probably first only renew the ground floor. The basement could be used later as a granny flat, but it is still in shell condition and is unheated anyway.

The biggest concern, however, is the roof. A few tiles have holes, in some places buckets were placed underneath and in others newspapers were laid out on tarpaulins. The newspapers show that the problem has existed for at least 15 years. On the ground floor, no water damage can be seen on the ceilings, but the penetrating water may still have caused greater damage.

Not to be overlooked is the cladding on the weather side. These are probably asbestos façade panels, beneath which is bare masonry. I now know that if more than 10% of the plaster needs to be redone, insulation must also be installed. Does this requirement also apply if there was no plaster present at all?

Because I definitely want to avoid façade insulation.

Are there several oil tanks? What capacities do they have?
I have never heard of a requirement to replace heaters. You do it every x years because they simply break down. After 30 years, you can start setting aside money for a new one; it could be time soon.
If the water pipes are already damaged, what about the heating pipes? Since you already have all the walls open for electrical and water work, then just replace those as well.
Is the basement dry enough for an apartment?
You will want to redo the roof. To what extent the roof structure needs to be redone can only be assessed by a carpenter on site.

The oil tanks have a total capacity of 4500l (3*1500l). As far as I understand, according to the Energy Saving Ordinance, all heating systems older than 30 years must be replaced, unless they are low-temperature or condensing technology systems. Repairs to the heating system are definitely factored in, and even in the worst case, a new heating system is included in the budget. The heating pipes as well as drinking water pipes are in good condition. The entire heating system was only installed in 1990; before that, there were only individual stoves and instantaneous water heaters. Therefore, the drinking water pipes probably were also installed in 1990. The downpipes are definitely still from the year of construction, relatively thin cast iron pipes. Since the basement is mostly in a raw state, these are relatively easily accessible. The basement is in good condition; the hillside rooms (heating, storage room) are also plastered, and no moisture damage is visible here, except at the windows of the light wells, which need to be resealed; here there is only an old, porous sealing compound between the frame and masonry. The rooms facing away from the hillside are unplastered; unfortunately, moisture damage would be much harder to detect here. However, the masonry and the floor slab (still without screed) look good so far.

Then it all seems somewhat manageable after all. Buy