A noun meaning a newly built building or the act of new construction; can also be used as a verb in the form '新築する'.
私たちは新築の家に引っ越した。
We moved into a newly built house.
このマンションは今年新築されたばかりだ。
This apartment building was newly constructed this year.
会社は本社を新築する計画を発表した。
The company announced plans to build a new headquarters.