G'day guys

I'm new here so please forgive me if this has been discussed before.
I have an old weatherboard that is basically built off the ground on piers with an underfloor space ranging from 1.6m to 2.1m in height and it's about 5.5m wide.

I have piers every 1800 and want to remove them so I can turn some of the space in to a living area/laundry/workshop etc.
I have had the new steel beams designed by an engineer but he has advised I need my footings checked on the external walls that will now take all the weight.
I have dug under the existing brick work and found there are no footings so I'm wondering what the best option is?
I can either put a new strip footing in in parallel to the external load bearing wall, put in some piers to support the new beams or underpin the existing brick wall.

any ideas about the best option - taking in to account I will be moving all of the weight to the external walls rather than the piers that are currently in place to support the house?

Cheers