Fireplace removal

[carlsbergy]

Hi, I have had the fire places on the ground and first floor of my house removed. Due to the neighbour on the other side having their's removed and using gallow brackets, in conjunction with building control a steel on my side was fitted to support the stack above the first floor. I now need to cap off the chimney at the top and was planning to use a c cap which stops rain and allows in ventilation. Should I also fit an air brick at the bottom of the stack (above the first floor ceiling) to allow ventilation all the way through what is left of the stack? Thanks