@jkmwatha, kenya happens to be lucky to have underground rock suitable to be cut into building stones. Most parts of the world, inluding most of africa, dont have this hence they have to rely on fired clay bricks and prefabs for housing. Once the stone quarries dry out in the next 5 years, there will be very many new methods of constructing such as prefabs, bricks , earthbags etc. Cost of prefab walling can go down once we research into nower methods of reducing costs eg the wire mesh in the prefab can be replaced with polypropylene fishing net for the same effect...after lengthy research ofcourse to check if this is possible .. Once we invest in research, then there are hopes of bringing down these costs.

@kratos, thats my estimation, based on the scarcity of quarries at the moment. Kilifi quarry is already nearly finished, with the operators moving to Juja. Juja quarries are also nearly finished. Currently, to get a good quarry mine in Juja is not easy plus the costs are too high due to the scarcity. A good guestimation for the stones to finish is around 5 years but could take less or more.

I totally agree might be the reasons why stone prices are going up every month in Juja. Also most quarries are now relocating from Juja to BAT area along Thika - Garissa rd in search for quarry mines

I called Nhc recently and was tol that a 3m by 1.2m wall panel goes for about ksh 5,750/=. The slab panel of the same size goes for 6,570.
I asked a Qs friend about the panels and he told that they would only be cost effective if you are bulding something thats bigger/large scale. probably over 1000sqm.

what if it's a 4 storey building with 250sqm per floor?

How did this turn out for you?