Don’t you know that there are still several buildings constructed with low quality materials and unskilled laborers without any accident (like building collapse, etc)?
Yes, there are such buildings. People should be aware of the term called “fatigue” in building. Those buildings built with low quality materials and/or unskilled laborers may be safer today. But it may not be safe in the long run. My point is, a building (be it a home / apartment / commercial one) should last at least for few decades. You don’t have to build a Taj Mahal which lasts for few centuries.
