I was talking to a colleague today who owns some commercial property and he stated that whatever commercial building one builds try and recoup your investment and make some profit within the 1st 20years, as buildings made out of blocks have a life span of about 25 years after which you may need to do some structural work to strengthen it. Also the PVC plumbing would start leaking inside walls and floors after a while once the gums used in joining the pipes lose their adhesive strength. Roofs sag as the wooden beams weaken making it necessary to change the entire roof, also electrical wires degrade after some years and may start overheating and could cause fires.

If a plot of land generates 1million per annum, has a yield of not less than 8% and payback of not more than 12 years would you consider that a good investment? If not what is your investment treshold?