I spent most of my 20s working for an electrical contractor on construction sites on the mainland. Building things that would likely outlast me was a satisfying job, and I get a feeling of permanence when I drive through Glasgow seeing the lights on in people’s homes knowing I fitted the fuse boards that power them over 20 years ago. I miss being 'on the tools’ but I still take pleasure in renovation projects and DIY.
In terms of psychology, DIY is a surprisingly complex subject. Whilst many people unwillingly undertake projects just because it’s cheaper, there are many positive and often subconscious reasons why we’re driven to it. Doing DIY increases mental physical and mental wellbeing, and life satisfaction, but only if you start what you finish (and don’t physically injure yourself in the process).