Lifting a house is a big step, so I start by going over your walls, the foundation and the utilities with you, because each one changes how the lift is done. Before anything moves, every utility line has to be disconnected: water, sewer, gas, electric and phone. Then the house is separated from its old foundation, raised on hydraulic jacks and set on temporary supports, which hold the full weight while our crew digs out, forms and pours the new or extended foundation underneath, with rebar, the steel bars that keep concrete from pulling apart, set in the footings and walls. We let that concrete cure, which is the wait while it gains strength, before the house comes down onto it and the utilities go back on. If the budget gets tight, the foundation is the one place I won't trim, because once the house is sitting on it nobody sees it again and it's carrying your home for as long as you live there.
A raised house usually changes how everything around it meets the ground. Where an old slab, walkway or footing is in the way, we handle the concrete cutting so the rest of it stays whole. When the garage or front door ends up higher, a new concrete driveway or approach can be built to meet it at the new height.
Setting the house on a new foundation
This suits a house whose old foundation is cracked, crumbling or too short to be worth saving. We lift the house clear and pour a new foundation underneath, so it ends up on concrete that's sound from the footing up.
Extending the foundation you already have
When the existing foundation is solid and just needs to be taller, we can build up from it instead of starting over. That usually means less tear-out, and I'll only suggest it once I've had a close look at what's there.