I just remembered where the weights will be... in the brochure!
It doesn't tell me about 3 vs 5 door weight differences... maybe they are exactly the same... but I doubt it!
Things that it does show though are fuel consumption figures which are only different for DSG equipped 3/5 door vehicles - the manual box ones are identical.
It also shows me that DSG adds 30kg to the weight 1850kg vs 1880kg, which is approx. 1.6% heavier, which doesn't account for the ~10% increase in CO2 emmissions on its own, which either means that weight adds to emmisions in a non-linear way or that its a combination of extra weight and inefficiency - the latter sounds likely.
I am still 100% surprised that a 3 door and a 5 door weigh *exactly* the same. I find that hard to believe.