foundation on rocky terrain

Building Control would give a pukka answer, but rock ain't gonna move so I would say put the foundation straight on it.

 

I don't know to what extent Building Control would need to be involved given this is a garage, have you looked into this?

How deep is the rock below ground level and what depth would you be otherwise digging down to?

 

Again, as mentioned in other threads by myself, 'DYNAMITE'. See if Screwfix will stock it for you. If you find any Gold i want 30%

 

Rather than actual foundations, how about laying a raft over the rocks.

 

Good thing about a raft is that if the area floods at least it will float!

 

My question would be about the bank behind the new wall. what is to stop that moving if it wants to? Id want that wall fully anchored and strengthened etc.

Wouldnt matter if foundations were 2 inches or 2 feet if that bank moves, and water!

 

I guess if the digger couldn't make any headway into the rock then it is proper stone not shale. Common sense would be to build on the stone, what some inspectors will allow is a concrete ring beam with rebar inside with uprights set into the stone and tied into the rebar.

If you are going to use "hollows" then extend the rebar from the foundations in to the wall. The crux is going to be getting the floor level above the DPC and water table

I would build two walls one to retain the bank with a gap before the garage wall and also some land drain with a sock leading to a soakaway

 

Depends on the hill and soil. how much hill is there to restrain, is it mostly rock or a few feet of soil on top, etc.

Might be a case for some gabions? But any restraing wall is going to need to be anchored and reinforced. I like the idea of a restraining wall before the garage wall though

 

Leave building control out of it. An agricultural building more than twice its height from a building containing sleeping accomodation is building reg exempt. BUT

Don't call it a garage else your local planning office will say you are building a domestic garage on residential land, needs planning permission etc etc: whole heap of pain.

Having said that as the building is atricultural you will need to apply to planning, either for permission or permitted development if you have sufficient land (5 hectares i think)

 

And then when you sell the property you have a non compliant building

 

Wrong. Agricultural buildings are reg exempt apart from parl l and i doubt that applies. See here
https://www.planningportal.co.uk/info/200128/building_control/38/building_regulations/2

 

It is garage not a livestock building

 

what has livestock got to do with it? post #8 : it is an agricultural building on agricultural land according to the OP. I presume he means a garage for agricultural equipment...

so if i am following this, you suggest the OP gets building regs for garage: and then worried about selling a house without building regs? what about planning permission? a garage on agricultural land is change of use: 10 year risk of enforcement versus 1 on building regs?

 

Regardless of the potential use of the building he needs proper professional advice by somebody on site.

Doesnt matter what is in the building if the hill behind it is unsafe and not restrained.

How would your conscience be if the building was flattened by movement and anybody was in there.

This project is more involved than just the cheapest way of doing it