Hello, I would like to demolish part of load bearing wall to have open kitchen and living space. There is an existing door on the wall and the new opening would be about 2.6m I think we need a lintel for supporting upper floor structure (mid terrace house small house). This could be a RSJ steel lintel or concrete lintel. Anyone could help to explain their advantages and dis vantages. I also see on some lintel' manufacture website, they could also do simple structural calculation to identify the size of lintel. Is it sufficient for building control? Many thanks.