I want to build a child's bedroom and chest so I can adopt. I have the Falkreath property and have build a sizable house there, but I don't see "addition: child's bedroom" on the drafting table, and when I try to adopt, the only option I have is "I do not have room for you". What do I have to do first to get the option to build a child's bedroom on the drafting table?

Did you already build the west wing? If not, then build the bedroom addition. There is no "children's room addition." Alternatively, build both the single beds in the main hall second floor and build the dresser. This will provide a place for the children to sleep.

The Falkreath home has the children's beds (2) in the lower level with the master. An option for a seperate children bedroom is not offered.

Dagal

I don't have an option to build a west wing. A north wing, and I just built a kitchen in the east wing. Oh I think I know. I built the enchanter's tower, THAT was the west wing. They should have made the drafting table more intuitive, like show all possible options at once, but grey them out when one of your selections would replace or cancel it.

That way I would have known that I could have built the children's room, but the enchanter's tower replaced it. Just taking it off the drafting table when I built the enchanter's tower confused me, because I didn't actually read all the possibilities for the west wing, and didn't understand that you couldn't build them ALL, just one of them.

Thanks for the reply, I understand now.

You can still adopt, just build the single beds in the main hall plus the dresser.

you don't need a bedroom wing either. the upstairs will have three beds anyway for the homes you can build.

Yup, what cap said. Build the upstairs beds and the dresser. Your kids will sleep up there. Have you not build any inside furniture? And didn't you just asked that question in the Spoiler section as well?