The largest DIY project I have done--> finished my basement. A year long process from which I learned Building permit, related building codes of Framing, HVAC, Plumbing, Electrical,etc. The whole process went through designing, building permit application, actual works including framing, rough/finished electrical wiring, rough/finsh plumbing, ventilation , drywalling, painting, flooring, and inspections of every step.
Even I am ECE back ground, the only failed inspection was finishing electricity due to the electrical code change.
Basically, here in north America, similarly in the US and Canada, it is legal to do anything in your own home, as long as you follow the trade codes. Actually, the differences between the two countries are less than that of the territories in the same country. As long as you know what to do, how to do, and follow the two principles:
EWD+KISS: Engineering Without Border and Keep It Simple Stupid.
说多了都是泪, too much to write, impossible to describe the whole project in a few lines. Here I shared a plumbing failure story "Plumbing mistake"; Viewer discretion: it's written in Chinese, pure technical & tedious.
The designing 3D model is appended here:
