There's folks who're recreating stuff like Helm's Deep or Minas Tirith or Notre Dame in game and those builds look awesome. You probably can spend the rest of your life in Valheim, building stuff, as long as you don't run out of inspiration. I got on and off phases. Just spent a couple hours in game decorating my newest house. Took me about six hours to build it (and it's mainly wood and some core wood - huge stone buildings like, e.g. a castle, take a lot longer). Could probably easily spend as much time on decorating everything so it actually looks lived in (finished the kitchen today, took a lot of playing around with item stands but in the end it worked out).

You can use stuff for things other than its intended purpose (e.g. round wood shields as plates, wooden tower shields as platters, mushrooms or glowing trophies as lighting, etc.) - just use your imagination and try. Or watch a ton of building videos on Youtube to see how other people do it. Maybe indeed start off by watching some building videos on Youtube to see if you like it.

If you're playing solo, you can also enter creative mode via the command console, which allows you to build without material costs (read: build everything for free), if you just wanna build and don't care too much for the rest.

There's folks who're recreating stuff like Helm's Deep or Minas Tirith or Notre Dame in game and those builds look awesome. You probably can spend the rest of your life in Valheim, building stuff, as long as you don't run out of inspiration. I got on and off phases. Just spent a couple hours in game decorating my newest house. Took me about six hours to build it (and it's mainly wood and some core wood - huge stone buildings like, e.g. a castle, take a lot longer). Could probably easily spend as much time on decorating everything so it actually looks lived in (finished the kitchen today, took a lot of playing around with item stands but in the end it worked out).

You can use stuff for things other than its intended purpose (e.g. round wood shields as plates, wooden tower shields as platters, mushrooms or glowing trophies as lighting, etc.) - just use your imagination and try. Or watch a ton of building videos on Youtube to see how other people do it. Maybe indeed start off by watching some building videos on Youtube to see if you like it.

If you're playing solo, you can also enter creative mode via the command console, which allows you to build without material costs (read: build everything for free), if you just wanna build and don't care too much for the rest.

Valheim has basically the best building system to date. It's both free form and simple to use. Easy to learn, yet tremendously deep. It encourages and facilitates experimentation and creativity. It's your most powerful tool, and using it is very satisfying.

The fact that Funcom is planning on revamping CE's building system to be a lot more like Valheim's says everything.

There are fewer building parts altogether then in some other games, but the building system is incredibly intuitive and fun to use. They spent a lot of time and polish on the building system, and compared to a lot of other games, it's very very very easy to use.

And there are creative ways to use even the basic parts to create incredibly detailed artistic builds.

That's exactly it. You don't need as much parts (more are still welcome! Triangles please!) as in other games, because you can do so much more with them.

No NPCs.

As for how deep the building capabilities are, you can look on youtube for some pretty impressive builds to get an idea of how far you can push this thing.

It's not as detailed as Conan. There are no NPCs in your build.

Take a look at the screenshots to see what other people have built. There is wood and stone, and later on fancy wood pieces, glass cubes and roof shingles. There are also natural and crafted objects that glow, and some decorative items and furniture. The game has smoke mechanics so you have to make a workable chimney, and it has rudimentary load-bearing physics. You will need extra support beams, but natural rocks and building around trees (tree houses) can give you more height.

If you're into that, there are mods that give more building options.

Edit: I should add that limited terraforming is available, raising and lowering land, but you can't dig tunnels.

wood 2 types regular wood meadows, core wood black forest
stone swamp <need iron for stone>
iron hybrid swamp
tar plains
glass mountains

That's about it I think beyond decoration types.
In order of progression glass is before tar.

There’s no NPCs in the form of other humanoids, but you can tame wolves, boar and even the big furry Lox in the plains and they’ll defend you or your base. Though the Lox is more likely to break your stuff than actually help.

Building in itself is IMHO much better than Conan Exiles. Unfortunately, as already mentioned, absolutely no NPCs.

You are alone. Unless you play with others.

You start with wood. You need to get into current mid-game before you get stone. Current end-game will give you another wood variety.