Another piece of advise, When you buy a plot dont fence it immediately , its waste of money as the fence will likely come down during the construction and you will need a fence when you finish construction instead mwanga mawe and get drawings with the fencing money first.
Fencing an eight acre can cost you up to Ksh40000-50k in Nairobi/ mavoko.

But make sure that you keep on visiting the plot frequently lest cons invade your plot. Also create a rapport with your soon to be neighbours so that they can report to you anyone trying to trespass into your land.

Did they give you a business card with contacts...their website doesn't give physical location or email address. If you have please share. thank you!

I don't know if that's cheap especially that u want to build the whole house with sh.420,000. Roofing is supposed to take up to 10% of the whole cost of construction. If u were roofing the usual timber truss way with whatever roof u choose and it costs u sh.160,000 to do so, then it would mean u were building a house that costs around 1.6 million or thereabouts. If this new roofing technology is cheaper, that would mean the sh.160,000 shillings(what it costs to roof a 2 bedroomed house with the complete roofing unit made with the new technology) would be the cost of roofing for a house that would cost way above 1.6 million shillings, it's the only way it would be considered cheap.Well! i stand to be corrected or maybe the people who came up with the maths about roofing taking up to 10% of construction cost should do some revision.

If fencing a 50x100 plot costs 40-50K, how would construction of a house in the same place cost 420K.

In syokimau that kind of money (420k) is what it would cost to do a foundation of a basic bungalow.

Granted with that kind of money one could do a make believe hse (the type you see upcountry) on red soil. One would have to use very basic material - where quality is not a factor.

Lets be practical folks.

what would be the cost of the foundation? i know the foundation takes quite a big part of the total cost of costruction especially if your plot is in a place that has cotton soil.