Help! Advice on foundation depth

[tracey6585]

We are buying a house 1920’s semi. There is some cracking in the ground floor bay. Surveyor thought linked to collapsed drains. I’ve had a geo technical survey done. All is well however a test pit a bit further down side of house has discovered the brick foundations are 400mm deep with a 50mm step out. He’s identified that there is a limestone gravel trench under that. Do I need to worry? They’ve mentioned that new builds are on 1000mm foundations but it’s an
Old building. Also the 3 other bore holes have sandy limestone soil in which gets more compact until it hits limestone bedrock 2m down, so the gravel under the foundation
Is very different which makes me feel like this is specifically to support foundation. Your opinion would
Be lovely

 

[Lime]

IME the foundations described are quite usual for the age of the property.
From the information your geo technical survey gave you it tells me they know next to nothing about the foundations of older buildings.

 

[tracey6585]

Thank you. There are loads of these down the lane so I thought all ok but not dealt with foundation issues before, just makes you nervous!