1. First carry out a search at the lands registry. This should identify the owner of the land, the size and any caveats/cautions on the land upon which the house sits on.
2. Get a copy of the land owners id card and verify his identity at the registrar of persons, just to make sure you are not dealing with a conman.
3. Ask for the city council and NEMA approvals to ensure the project has been cleared by the relevant legal authorities.
4. Assessing the structural strengths of a house can be challenging for a layman but you should look at the concrete works before plastering e.g slabs, columns and beams. If they appear honeycombed it is a sign of poor concreting.
5. Check to see if the wood in the roof is treated, ideally it should be a greenish/blue color.
6. To see if tiles were fixed properly, tap them with a key and if you hear hollow sounds it indicates poorly laid tiles which will start cracking upon impact.
7. Pour a bucket of water in the bathrooms to ensure that the slopes are going in the right directions, you don’t want puddles remaining.
I could end up writing a very long list that might not be particularly helpful, can you please be a bit more specific in the issues you need to be addressed.
Before you can be be old and wise, you must first be young and stupid.