Hi
We are currently having new french doors installed which meant taking out an existing window 900mm and opening it up to 1500mm to accommodate new french doors. There is a concrete lintel in that was above the window but my builder is putting in 2 - 10mm thick steel strips 1 on the brick course and 1 on the block course. He is leaving the existing lintel in place. Is this ok or should there be a proper lintel going in?

Thanks in advance.

Thanks Kentishbuilder... He has already put these in and we have already had all the internal plastering done..he said that the concrete lintel that is in already might cause damage to the block work above if heremovesit as it's a boot lintel?
Is there any way I can make him rectify it as he is due to complete the work this Friday. Would bringing in building control help?

Thanks Rowan

Unfortunately I hired him off this website as his feedback seemed very good.