Learn German: Dieser Neubau ist teils gepflegt, teils schon kaputt. - This new building is partly well-kept, partly already broken.

teils ..., teils ... acts as a multi-part coordinating conjunction. In this sentence, it connects two adjectives (gepflegt and kaputt) rather than two full clauses. Because it is only linking adjectives that describe the subject, it doesn't require a second verb or change the word order of the main clause.

Could I use zum Teil instead of teils in this sentence?

Yes, you could perfectly say zum Teil gepflegt, zum Teil schon kaputt. Both pairs mean partly..., partly... and are interchangeable here. teils is just an adverbial form of Teil (part) and is very common in both written and spoken German because it is shorter and flows nicely.

Why is a building described as gepflegt?

The verb pflegen means to care for or to nurse. Here, its past participle gepflegt is used as an adjective. When applied to a building, a garden, or even a person's appearance, it means well-kept, neat, or well-maintained.

How can a Neubau (new building) be schon kaputt (already broken)?