Connected outbuilding to potential kitchen or office, stepped brick foundations

[Mr Chibs]

Wondering if I could get some opinions from you guys please.

I'm updating a 1900 cottage with single storey extension, attached to the extension is small barn like structure that was just used for storage. As things have gone on, I'm now thinking of utilising this building (originally going to be my man cave).

I suspect the building to be older that the house, I've had a dig around the floors and there are stepped brick footings/foundations.

The building is 6.9x5m and is around 5m to roof apex.
There is a crappy old mezzanine that would be removed.

As red areas on photo, these are 450mm (ish) sq piers, 4 of them, none at the left handside gable.
On top of piers sit some chunky beams.
Roof looks in fairly good shape, but sister rafters have been added, and a couple more may need doing.
I'm contemplating re-doing the roof, should this be needed.

The 'barn doors' may be removed and replaced with half height brick wall, and window added... what got me thinking is how would I prepare footings for this, as the original structure is only stepped brick.

Is this a total daydream or worth the effort?

Thanks in advance.

 

[tony1851]

Just put in a concrete strip footing to the same depth as the existing stepped footings.

 

[Mr Chibs]

Cheers for that, I didn't really know if this would suffice, but that said, the structure has stood for many years.