Contractor fees

Fellow talkers,

Lawrence lual malong yor is intending to upgrade his country hacienda somewhere in south nyanza region.

I have the design and have done BoQ with regards to cost of materials ( a 3bedroomed house)…my question now is…

How much should I pay for a contractor for this size of house or is there a rule of thumb/ formula regarding this?

Experts in the house kindly advise.

10% of the BQ/QS