New window next to where the old window was.

Hi, we had a conservatory and used the kitchen window aperture (marked in yellow on the pic) for one of the doors which was narrower than the window so breeze blocked the remaining hole, now we want a kitchen window (marked in red) right next to where the window was.
My question is about the lintel (marked in black) how would this work? would i need a lintel above a 500-600mm wide window and if so how should it be fitted please?

 

Is it a single storey ?

 

No, it has a 4' bedroom window directly above, outside is rendered and I would like not to have to replace the existing lintel with a wider one which is probably the correct method, but this will turn it into a mammoth job, as opposed to cutting an opening and fitting a window like shown.

 

and after hopefully

 

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Please select a service and enter a location to continue...

Plumber / Gas Engineer Electrician Builder Decorator Builders' Merchant Plumbers' Merchant Tile Supplier Flooring Supplier
Start Search

Are you a trade or supplier? You can create your listing free at DIYnot Local