Building a cavity wall on a single wall below Information, help and advice on many architecture, self build and design problems and issues

[knuckles]

Hello, Im moving my garage forward onto the side of my house and building above it as well. Due to the drive being narrow at the front I am going to build a single leaf wall for the garage. The wall above the garage will be cavity wall. I know this can be done by buidling pillars into the single wall below and then spanning them with lintels, but, what is the minimum width of a pillar for this type of job? And, would one pillar in the middle of the garage wall be enough? The single wall will be 6.3m long.
Any advice would be appreciated,
Thanks.

[welsh brickie]

The lintol will have to be steel as the spans too long for 1 pillar.You can use CATNIC CN5XA box lintol the central pillar will need to be a minimum of 300mm wide the minimum bearing for a pillar is 150mm

[Perry525]

To make this work, you need to know the weight of the building and its contents.
You need to know what type of ground you are building on to work out the size and type of foundation.
One you have the information, only then can you work out how to support the load. Brick is very good in compression.