Adding Room Advice Please

[Romano]

hi,
I am creating a new second floor bedroom on top of a already existing level one room, this new addition will be in brick, but tile hung to stay in keeping with the rest of the property.
My question is i am thinking of adding in a pre cast concrete sill underneath the window to add some charm?
I am just checking as have never seen a property with this, is there a reason as normally under the sill is just some lead folded over?

Help please

 

[freddiemercurystwin]

What's your cill gonna sit on without creating a cold bridge then?

Edit: Oh hang on, you say in brick but tile hung? Are you doing a cavity wall with a brick cladding or are you doing an inner skin of masonry with insulation and then tile cladding? If so why brick?