Of course in theory this is relatively simple. All of the stuff that you need to do home automation and smart house features is available off of the shelf in plug and play type options. You can can find videos on youtube on how to install all of the individual components, and videos focused on a particular type of system like fibaro for example. The reality is probably going to be a bit different from the theory however and I would guess that I might learn some hard lessons from trying to do it without getting an expert to show me how it is done. Of course the theory is also going to depend on your level of ambition and how much complexity you wish to build into the system.
It is entirely possible to build something off of the Sy Fy channel where you would have a house that could recognize who you are and whether or not to let you into the house. In fact you could get a house to recognize the pool guy and let him walk into the patio to do the pool, but obviously not let him through the back door and into your kitchen to eat your bratwursts and drink your beer. In practical terms you can have a wireless entry keypad with a code in it. You might have one code for people who belong in the house and another might just be temporary, perhaps for the plumber who needs to fix the leak in the kitchen sink at 1 PM on a Monday or some such time. I am not really interested in that level of complexity. I will use a keyless entry pad, but it does not have to be that smart at all in my current plans and concepts.