noun
Refers to the construction business sector as a whole, including companies, workers, and market trends.
建設業界は人手不足が深刻だ。
The construction industry faces a serious labor shortage.
建設業 refers to the construction business or trade itself, while 建設業界 emphasizes the industry as a whole, including its market and community.
Compound of 建設 (construction) + 業界 (industry, business world).