is it safe for babies to sleep in a basement?

Hye, I think yeah you should check for all that before settling the baby in the room. If everything is fine why not , the baby won't be staying in the room 24/7 , she will be in other room of the house I expect,

As long as there is no mold and no gases leaking and you can control the temp. and things like that it should be ok. The basement part isnt an issue, its the conditions in the basement that make it or break it.

basements are the ideal breading ground for toxic mold. i wouldnt even chance it unless there has not been any previous humidity/water problem and you can control the air flow 24hrs in the basement. Ventilation is primary

As long as it checks out it will be fine. My son moved down to our basement when he was one because he wanted a big boy bed and we were planning to have another child so we didn't want to move the big boy bed twice, plus we didn't want him to think he was being kicked out of his room because of another baby. He loves it down in the basement. It is his own little place. He has one small window, it does not have a ceiling fan, but it stays cool down there and warm in the winter.

Unless you have mold then it should be fine.