I need a guide on how to go about constructing my own house
Start from having an architect draw a plan, including structural by an engineer.
Then go for approval at your areas county offices.
After get approvals, start the build.
Tafadhali gave space for a tree or two, don’t build a concrete jungle.
Think of the environment 
It maybe a timber and tin shack he has in mind.
He wouldn’t need an architect for that.
Isorait but he didn’t specify. As long as it’s his place.
Yes you have to always go through that channel, even for a chicken farm.
Seen guys getting approvals.
Word of advise, always go by the law, saves you alot of hustle later…
You need to give more details, do you own a plot? Where? What size? What is your budget? etc this will help us guide you since we have had many such projects, and each project is unique…