I got good suggestions from you earlier. SO I am here again.
We bought a rekkehus of 35 years old. There are many small and few large upgrading is required to make it to the current level.
1. When it comes to renovating the bathroom (currently no heating, no tiles), I was told that I should use approved companies to do the job. The cost of approved company is very expensive (200000 nok for 6m2). Is there any option that could help to renovate the bathroom using approved and less/reasonable cost? Where can I find this details?
2. How about kitchen? Does it need to be upgraded by approved person as well?
3.What is normal in case of rekkehus to change the roof tiles? Does this need to be done by all at the sametime or it is based on individual interest?
200K for a 6m2 bathroom sounds very expspensive. You can get it much cheaper than that. But it does cost money to renovate bathrooms. I do not recommend doing it yourself, unless you really know what you're doing. You can be held responsible for leaks or damages years in the future if you mess it up.
You'll just have to ask around for bathroom-guys to get quotes.
In a kitchen you only need a plumber to connect the tubes and pipes. The rest you can do yourself. It is pretty common doing that. But check prices for premade kitchen modules versus IKEA and other flat-pack systems before you decide. Premade modules might not be so expensive.
A rekkehus will normally have all external maintenance done in one go. It is uncommon to have the single appartment owners responsible for their parts. Talk to the chairman of the board of the borettslag.