Fyatu,
Another option if you are really hell bent on going with a construction company is to go precast. You will get way more than a skele for 1.6m



More here

Thanks @MugundaMan

Still maintain an independent professional is necessary. Practical example;

I had a kaplot with "red murram soil". When I was starting kuweka fence (at house design stage),the engineer requested a visit (which naturally I was against, coz this is just a simple fence ama....).

The engineer, with a simple look at the soil, demanded we do some more analysis befors proceeding. Being a novice in this area I reluctantly obliged (drawings were submitted to kanjo for approval around this time).

He later mumbled some sentences but requested I start with the Septic structure just so we "confirm soil profile".

Turns out the red soil was a "false red soil" with cotton soil below it (how is that possible btw?).

At the end we had to change the foundation to the floating foundation by boring shafts and using piles. Very costly!!!! But neighbours are doing/done their thing on the red soil.....I don't want to mention what they are going through!

Somehow my area is surrounded by other areas which have the red soil and rock below it!

Well, not to mention that that ka-fundi (who I fired later) had said that "all coffee areas have very compact volcanic red soil, be assured, nimenjenga mingi sana huku"!!!

On the professional tax, I reserved 100k but so far he has not exhausted it, na nko karibu roof....

On the big projects with an importance structure greater than 1, the clients prefer having an engineer/clerk of works on site (looking at projects like thika road, times tower, britam tower, UON towers, etc)
On small projects with importance factor less than one (bungalows and maisonettes,your simba and other small houses), having a foreman who can understand 1. Architectural drawings because of setting out, and 2. Structural drawings to ensure the structure will function as intended over its design life, and supplement the foreman by having the structural engineer come over and confirm his instructions via the drawings are being implemented.
Matters pay: The engineer would usually charge a professional fee, anywhere from 60-100k depending on built-up area. Before you scream expensive, this amount would be used to compensate for his time working on calculations that are usually submitted to the local council for approvals and also pay the draftsman who would produce the drawing, it would also pay for the printing of the drawings( also called plotting). Part of that would also cover professional indemnity insurance, so that if a problem arises with the structure and you sue him, the insurance would cover the same.
Over the duration of the construction, you would then pay the engineer for him coming for site visits, usually over the following intervals: After excavation, to check the excavated trenches for the strip footings and the pad footings, if any; Before concreting for the strip footing (confirm bar sizes used). These two are sometimes combined, in cases where the steel has been cut and tied while excavation is still ongoing; Before concreting for ground slab to confirm hardcore and BRC is as specified, plus inclusion of DPC in the foundation to ensure no water would trickle upwards; before concreting of suspended slab to ensure steel is of required diameter and recommended spacing, and sometimes before concreting of roof beam, for similar reasons as above. They usually request amounts in the range of 3-5k per visit (fuel,etc).

Finally, think of the many buildings that have collapsed, majority had an engineer who came up with the drawings, but the fundi on site almost always over-rode the drawings to save funds. always ensure you have an engineer recognized by the engineers board of kenya, and a fundi who will follow the drawings to the letter. If you have a query and you engaged an engineer, by the fact that you paid him will leave him open to receiving and answering your queries.

When you are unwell you see a doctor, not the nurse. When putting up a building you engage an architect and engineer. NB the building will outlive you and your children thus you should do things right.