Firstly remove all of the trimmings at the back and sides

clear the way and remove all of the side windows and chimneys

block up all of the holes in the side of the house

and break up the 20 inch deep concrete down the side (take a break if you survive this, very hard work!!)

dig loads of foundation shaped holes

and build a base for your extension

raise the edges and create a floor for your new building

lay the odd brick

and watch the building grow

you may need a ladder here

OK, more like a scaffold, oh yes a roof and windows will come in handy

render and paint...

Voila, one extension