The original owners of our house added a kitchen extension - extension 1 in the diagram. Extension 1 is open to the space I've marked as kitchen on the diagram. The dotted line shows the original position of the rear wall of the house.
The next owners ( our sellers) added extension number 2. This is accessed via an open doorway from the kitchen space. There's a large open serving hatch type thing in the wall between extension 1 and extension 2.
Kitchen units are currently fitted in a J shape in extension 1, extending up to the utility room at the top. Extension 2 is used as dining room. There's lots of wasted space in the original kitchen.
We want to open up the whole space to make a large kitchen diner, so we'll need an RSJ right the way across the width 'of the original kitchen and to remove the wall between the two extensions. We'd also want a couple of velux windows in the roof over extension 2.
So do we just talk to the builder about what we want to do or do we need to get plans drawn up first? If we need plans who do we need to find to do that (what trade/profession)?
House is a 70s detached if that makes any difference