Firstly, i hope to god the OP has gotten his answer to his question. Im not going to go into how his width increased because its measured from the centre of the road..... his house must be at 90deg to it... and thats a whole other issue....
Secondly, regarding whether the area is to include the road or not.. a few points..
If you agree to purchase a site of say 0.5 acres, that will the area of land you will occupy.... not including the road.....that 0.5 acres will be measured as actual land area.
Its only in the marking of Land registry maps does this 'middle of the road' issue occur. This is simply a residual convention that has continued since its inception. Therefore where your 0.5 acres is marked for land registry, its marked to the centre of the public road and the area the measured... so it could end up at 0.6 or whatever.
This actually means nothing.... it does not mean that you own the public road. You will see in situations where the road is not public that the area is not measured to the centre of the road. I supposed its just a measure to ensure all land is registered.