Hi everyone, I'm currently extending my 175yr old cottage. At the moment there is a small, flat roofed extention on the back. The original pitched roof and the flat roof meet on a wooden beam and as I'm adding another pitched roof the flat roof will be going. The architect has said I need to replace the existing wood beam with steel. How big a deal is this likely to be? The span is about 10m and it is supported by walls in four places along it's length. Would it be possible to leave it in-situ as it's got so much support? Sorry for the long winded and thanks in advance for any advice.