@Chaka,
From my own point of view,i would say black cotton can be used although you would need to add some amount of river sand due to the sticky nature of the soil and it would also present high levels of shrinkage than red soil.Let's say red soil especially from ant hills would be most ideal (I guess ants were not stupid..lol).....but that's just my point.I'll do some more digging(Pun intended??)

I have attended one of the 'seminars' conducted by Makiga guys. They discourage completely usage of Black Cotton soil. Best is red soil which requires minimal cement as a stabiliser (in the tune of 1 bag for 14 wheelbarrows of soil)- other types of soil will require more cement

I'll be waiting... It will be great to see some well finished house.... Like the ones done in SA for the same material have beautiful finishing.

Remember to take contacts and all the finer details.... it will help us.

@Mzee Njunge,

You are welcome, your good guidance when I was shopping for a plot in Uganda for a holiday home will ever remain evergreen in my memory. Simply put you suggested that I should choose either Entebbe road or Jinja road. My choice of Entebbe road was spot on. No regrets at all.

Asante Sana.

@Others
I am not in a vantage position to recommend a good builder (Fundi ?) as I do not reside in Kenya. Interact with honest and sincere house owners and they will give you a good fellow. But you also have to know the nitty gritty of building a house as you can not base all your judgements from the "expert opinions" as their recommendations may sometimes be more costly or too generous that attracts a lot of costs.

Go through questions for the architects column you will learn some new things.

Great topic.

Looking forward to the pictures and contacts.

I have also seen one using fine crushed stone (normally used for road construction)instead of soil though this is more expensive but still cheaper than conventional dressed stones. The resultant blocks were very solid.