I was looking into the construction game myself a while back
Im not sure about the tarrif's but the general climate an inefficiencies in municipalities put me off
They have gotten way worse recently
I worked out I would have property standing idle for 5+ years now trying to get everything in place before I started actual building
Before it was probably 2 years
Kind of put me off it
My 2c, I do a fair bit of work in some specialised areas of construction and it is a tricky business. Currently the Chinese and some bigger firms are eating nicely on SANRAL, some DWS, work on the KZN N Coast and in WC and maybe LHDA contracts but below that there isn't much. Some specialist subcontractors are also thriving but it is tight. A few have pulled off site due to non-payment, the "construction mafia" aka ANC councillors etc is an ever present threat and, with 15% VAT due on invoice, even delayed payment can kill you, let alone the tax rates. The clever live in SA but work in sub-Saharan Africa out of Mauritius "offices" but even there, payment can be "eish".