Houses from the 60s and 70s - what should really be renovated?

Hello everyone,

since the development of the new building area is taking longer than expected, construction won’t be possible before 2020, and there are already more applicants than plots, I will continue to keep an eye out for existing properties.

The houses from the 60s and 70s are probably the most suitable; from the 80s onwards, extremely large "generation houses" were usually built here, which are A too big and B too expensive for me.

There are usually two types of houses here. 1.5-story houses with (very) steep gabled roofs, often with flat roof dormers added later, and prefabricated bungalows, mostly from the brands Bien and Streif Haus.

I have already searched what feels like half the internet and have also inquired at a few companies. Most findings on the net and companies are anyway focused on renovations. Since I want to renovate now, and not in 20-30 years when defects accumulate, here is my rough summary:


- Roof: Replace concrete tiles, leave clay tiles. Avoid flat roof dormers, otherwise definitely reseal.

- Windows: Leave double glazing, regardless of the construction year. Thermal insulation glazing does not realistically bring enough benefit to justify renewal.

- Heating, Water: Remove cast iron pipes, copper remains. 80s copper often has quality issues. Possibly renew drinking water pipes. Cast iron radiators remain due to more pleasant heat and not necessarily less efficient. Remove oil, install gas boiler.

- Electrical: Remove systems without protective earth and with red insulation (red color of the phase becomes porous over time). Lines with brown/blue/green-yellow can remain, retrofit RCD, replace screw fuses with circuit breakers.

- Insulation: Insulate top floor ceiling, insulate cellar ceiling as long as no "damp cellar". Avoid facade insulation due to mold risk and costs.

Would you leave it like this, or add or change any points?

Prefabricated houses from the brand Bien were apparently already of good quality, but mostly with asbestos cladding. In principle, I would say leave it, but I fear that at some point there will be an obligation to renew them. Since then more than 10% of the plaster would be renewed, insulation will also become mandatory. Are there any cheap "replacement panels" available that can be installed instead and fulfill the insulation requirement without adding too much thickness?

Best regards Max

Would you leave it as it is, or add or change points?

Hello Max, this is already a good and very comprehensive list. You do a lot preventively. I also like your approach to insulation and mold. Regarding the electrical system, I would also reconsider the circuit breakers. Sometimes half floors were covered with only one 16A breaker. Today, there are more consumers. Many houses from that time had very small kitchens. Possibly a wall needs to be removed to integrate the kitchen into the living area. Greetings, also Max

Roof: Replace concrete tiles, keep clay tiles. F

Concrete could also remain. Just check if they are intact. Usually, it’s only moss on them, and moss is a good thermal insulation.

Avoid flat roof dormers, otherwise definitely reseal them

If they are dry, then you don’t have to avoid them.

Windows: Keep double glazing, no matter the year of construction. Thermal insulation glazing does not bring enough benefit in reality to justify replacement.

Yes, that’s true. But usually the window frames are rotten. Or leaky. Try to slip a piece of paper in and pull it out with the window closed.

Prefabricated houses were often built with many toxins back then. I once posted a thread here about an older prefabricated house which was full of formaldehyde and that kind of stuff. Here it is:

Hello Max,

I just renovated or refurbished a two-family house from '68 myself and can give you pretty good information about what will probably need to be done.

Heating and Water:

At that age, everything simply needs to be new, whether copper or galvanized. Especially with galvanized pipes, all the threads will already be heavily corroded and will break under the slightest stress. The pipe itself would probably last another 40 years.

You also won’t be able to use the cast iron radiators anymore, as these were mostly designed for flow temperatures of 85°C or higher, which you certainly won’t want to run with your new gas boiler. Additionally, here, too, the problem is that the individual cast elements of the radiator are screwed together and are therefore probably heavily corroded as well.

Wastewater:

We once had a pipe blockage and the old cast iron pipe became like a sprinkler, although under normal circumstances it was tight, so completely new as well.

Electrical:

Depends entirely. In my case, everything was already wired with three-core cable, but black (live), gray (neutral), red (protective earth), and also a residual current device installed. Unfortunately, grounding was only via the neutral conductor before the RCD, so at least a ground electrode or something similar must be installed here. You will also have to upgrade a lot in terms of sockets and therefore pull several meters of new cable. Converting the fuse box to circuit breakers is then the smallest problem.

Windows:

Are most likely all rubbish, unless they were replaced at some point. If you are handy and watch a few videos, you can renew windows yourself for relatively little money, it’s not rocket science.

Roof and Insulation:

My roof tiles will be new next year, but only because they no longer look good and I want to convert the attic, technically not necessary, and can also be redone relatively dust-free later.

Basement ceiling insulation is also a thing... you will definitely have to install radiators in the basement, because otherwise it will get pretty moldy if it’s not heated at all. Whether it still makes sense, I’ll leave open. If you’re unlucky, you’ll have problems with room height anyway if the basement, as was often the case back then, is only 2 meters high.

Plaster, Wallpaper, and Carpets:

This point should not be underestimated. My family and I spent days and weeks just scraping wallpaper. Often there were 5 layers or more on the wall. After that, apart from all the slots for water and electrical lines, you have a real crater landscape. Also, the surface structure will most likely not be nice enough that just filling and painting over will be enough. So at least: completely new fine plaster or wallpaper on top.
Same story with the carpets, glued down everywhere and with foam backing, so you can’t just rip them out and put new flooring over them.

If you have everything done, you’re surely looking at a minimum of 150,000€ including new bathrooms.

I (heating engineer master) and my brother (electrician master) did all these jobs ourselves and took over a year.
That means really hard physical work and a year of working hard every free minute.
I don’t know if a layperson without specialist knowledge can pull this off??

And one more thing:

But whatever you do, don’t get a prefabricated house from that time. My parents had an Okal house (at least I think so) prefabricated house from ’73. Recently they moved into their new build and I was honestly shocked at what an extreme stench from all kinds of emissions accumulated there after a few days without ventilation. Really frightening and certainly not healthy!!! Sound insulation was often a foreign word in prefabricated houses of this era as well.

If you have any questions, just ask.

Regards

Back then, smoking was considered good manners. If the former owner smoked heavily, then you want to voluntarily remove the plaster throughout the entire house. That’s the fate I drew.

Given the year of construction and depending on the condition, one can wonder what is still worth preserving. In my case, that is the wooden stairs; otherwise, everything out and new.

Regarding the windows: [Rollladenkasten] are probably also completely uninsulated.

- Windows: Keep double glazing, regardless of the year of construction. Thermal insulation glazing does not really bring enough benefits in practice to justify replacement.

Thermal insulation glazing from 1994 with infrared coating (search for window lighter test) has a U-value of 1-1.3 W/m²K. The panes used before, which can look EXACTLY THE SAME, have a U-value of about 3 W/m²K. You can calculate about 80 kWh/year per m² of component area for each improvement of 1 W/m²K in a component. Ventilation losses due to missing sealing layers contribute an equally large value to heat loss. In many cases, replacement is worthwhile.

I would see everything else similarly. However, for the electrical system, I would generally renew everything for a 1960s/70s standard. Back then, significantly fewer sockets were common, light switches were often deeper, network cables of course did not exist, and you could usually count the fuse circuits on one hand.

In our 1959 solid construction bungalow, we did almost everything new, but the old roof is still on: concrete roof tiles Frankfurt pan with roofing felt as a waterproof layer. At the ridge, five tiles were replaced, the old roof penetrations from the ventilation removed (valve head in the attic), and otherwise everything is tight. There is some moss on it, which will be cleaned this summer. Replacement costs are about €150/m² WITHOUT insulation (we have sufficiently insulated the ceiling).