When I bought the house, it already had floor heating across the entire plan... but from what I see, it's not that hard to DIY if you're so inclined. Specially with floors like are typical in Sweden, it's like laminated flat boards that are easy to replace: https://www.bauhaus.se/hpl-laminatgolv-berryalloc-ek-vitolja...
It looks pretty good too... you need to do some cutouts for the warming pipes underneath, there's lots of Youtube videos showing how :D
But luckily, my floor heating apparently is still in very good condition so it will be a while before I have to replace that.
The floor heating itself isn't that expensive, the problem is you need to redo you floor, which sometimes means destroying it and doing a new install. We wanted a new floor anyway so not a problem, but if you have something expensive it will add up.
It looks pretty good too... you need to do some cutouts for the warming pipes underneath, there's lots of Youtube videos showing how :D
But luckily, my floor heating apparently is still in very good condition so it will be a while before I have to replace that.