• 建物たてもの — building
• 建設けんせつ — construction
• 建築けんちく — architecture
• 再建さいけん — reconstruction
• 建国けんこく — founding a nation
• 建前たてまえ — official stance, facade

The kanji 建 originally combined a brush or weapon element with the “long stride” radical, symbolizing taking action or extending forward. Over time, it evolved into meanings like “building” and “establishing,” whether it's a house, a company, or a government.

新しい家いえを 建たてました。
We built a new house.

建設けんせつが 始はじまりました。
Construction has started.

ケン and コン are used in compound words like 建国 (founding a nation) and 建築 (architecture). たてる and たつ are used when speaking more generally about building or standing up, like 家を建てる (build a house).