Check with a4architect

i partly agree with Architect. the general rule of thumb is 19 - 24% of the overall cost of construction. this however depends on the kind of finishes one uses. take for instance where floor tiles cost say 3000 per sqm while in another project a client uses tiles worth 1000 per sqm. In the 2 instances the labour cost of fixing tiles is the same.
for a detailed cost estimate i 'd recommend you consult a qs ( an experienced one - not all are knowledgeable to give such figures)