Load bearing wall move door way

[S J]

Hi all
First of all I'm sure this is going to result in you guys requiring more infomation, but I'm thinking of moving an internal door way across to give better to both rooms. It is a load bearing wall and was looking for advice on what sort of lintels I should be looking at purchasing 100mm box section steel/concrete etc etc and measurementsa and percautions I should take when obviously removing the original lintel to fit the obviously longer replacement lintel.
Thanks in advance

 

[mikric]

You will need to contact your local building control before you start.
How wide will the new opening be ?

 

[noseall]

if the finished opening is likely to be less than 1.2m the a simple 100mm x 75mm p.c.c. builders lintel will suffice.