If you are having carpets fitted it may well have been fortuitous to discover this problem now as if you are getting smells coming up from under the floor you will also get dirt, which over time will discolour the edges of your carpet & be really annoying on any light colour. Get some decorators caulking or expanding foam ( depending how big the gap between the skirting & floorboards is ) and seal around anywhere you are going to lay carpet.