I am currently putting up an apartment building, and my experience is that you the owner, must be on site to run things. Massive pilferage only occurs when you hand over the project to some 'foreman'. Fundis hardly get an opportunity to steal, after all, how many of you have ever lifted a cement bag to realize just how heavy it is? Kinda hard to run off with many. Fundis generally rob each other of tools. Your foreman is your problem, he's the blood sucking vampire.

If you can, purchase the stones, ballast and sand in sufficient quantities, then take 3 months leave from work to be on site daily. Only pay cash at delivery for these materials. Dont trust anyone, always verify quantities.

The best way to deal with fundis is to allocate production quotas. For example, each of my fundis for walling must per day use up 6 full wheelbarrows of mortar at 1:4 mix otherwise I sack them immediately. For plastering its the same, electrician is by contract. Ive paid the electrician 7,500 per every two bedroomed apartment he completes. etc etc. If you will not be at the site DAILY please add 1.2 million to your budget. If you hand over to a construction company, add 1-5 million to whatever budget you have.

Lastly, 29,000 kshs per sqm is too expensive. My direct experience is 15,000 kila kitu. However, finishes is up to you, why you would need to install toilets that cost 45,000 is up to you. Construct your own home, its quite an experience and not as hard as people fear, as you know humans can get used to anything. At first it will be challenging but very quickly you'll get the hang of things unless you are thick. Goodluck.

@Mwafrica31, very inspiring and an eye opener as relates to the foreman and being on the ground.
Me thinks that those quoting sh 29 000 per sq metre are just trying to discourage folks from venturing on their own..these are ridiculous rates..i am with Pablo on this one...ama wanajenga Gigiri..and there is no way you are making 25% profit or less with such rates!..iko kitu..