They say that you pay for a site investigation whether you have one or not!  

If you are buying a site without having a site investigation carried out, you may be lucky, however it is more likely that you will not be.  Not on a regular basis anyway.  There is normally a reason why sites are undeveloped.  Even green field sites are not immune from ground condition problems which can significantly affect the cost of a development.   You need to know about this before you buy the land not when you are about to start construction.  The unexpected costs and inevitable delays affect your profit.

With proper planning, most problems can be overcome in a practical and economic way.  Shallow mine workings, made, variable or soft ground, old foundations or cellars, shrinkable clay soils, high water tables, are not huge problems to overcome in themselves, provided they are known about early enough.

We have experience of designing foundations in all types of poor ground and have come up with practical solutions every time.