At some point in the past, we decided to invest in sleeping time. We went for something that apparently people around us do not understand, even if it is common sense. What we did? Basically, we rented a house that was fully paid, in order to move close to work, and rent a house for ourselves (me+wife) at walking distance from work, instead of commuting (the other house was like 40-60 minutes driving from/to work). So, renting a paid house to a tennant, use the money to rent a house for us instead close to work.
The aim of this was to save one hour, one extra hour, and wake up one hour late everytime we go to work. In my opinion, the benefits are huge, with no extra spending. Saving so much time, gaining time, this is worth much more that living in a house that is yours. Time gained is so precious, I can't even explain. 3 hours saved per week is 6.5 days of extra time per year, and I use all of this for extra sleep. I hope my body will thank me later in life for all this gimmick.
And yeah, my family doesn't understand my logic, they would rather commute from a house they own instead of renting close to work.
Now that I finished my rant, here where I live, you need to meet some conditions and do an annual gas and electricity check, have the documents to prove it, have smoke alarms and CO2 alarms, have a secure house and a few more law requirements in order to be allowed to rent. There is also a special insurance if you have tenants, and the question of keeping the rent deposit safe (you need to let people pay at least 1 month's rent as a deposit, as a rule of thumb, in case they decide to go early and not pay). You need to return the deposit when tenants leave if the house is looking ok.
Tax implications - you need to pay a good part of rent received as tax, as it is extra income.