Sometimes a good strategy is to buy an existing home and realize savings in the acquisition as opposed to buying a recently built home. The savings realized in the acquisition can then be expended in updating the property and potentially expanding the structure.
There is also the option of buying an older property and demolishing it for build of an entirely new structure. The benefit of this option is that there are no surprises during construction during the project which minimizes occurrence of change orders.
Either strategy is dependent on the owner's budget and timeline. An entirely new structure will normally take more time to build than an addition.