IMO, if you'll rely on your brother (Architecture student) and Uncle (foreman, does he have any engineering background?), medyo mahirap. You could at least hire the services of an engineer to serve as consultant.

My father-in-law is an engineer and when he recently rebuilt their house, he really spent time and money on it. Nagtyaga muna siya on his half-buried house before he embarked on the job of tearing it down and rebuilding a new house since he knows the consequences of shortcuts and the costs of slowing down construction due to lack of funds. The result was a well built nice house with good finishing, where he spent roughly to 500K over his intended budget. I also saw that their old house which he also built personally (which was torn down to make way for the new house) was still very well-built even after 25 years and the onslaught of Mt. Pinatubo, and he still got to use some of the old materials (especially the thick wood beams) because he chose materials carefully back then.