How often do you use your engineering skills to improve or better maintain your home?

I have been impressed with the responses I have received to recent questions about heat pumps, solar power, and smart home technologies.  Clearly, engineers are more savvy about those technologies than the general public - and use that knowledge to improve and better maintain their homes. I wonder how often that technical knowledge is used to address everyday household problems.  
Also, are there certain topics (home based or other!) you would be interested in discussing?