FYI – I built a garage on a slope on the back of our lot in 2007, with the front of the garage at grade, and the back of the garage on a footing 11 feet below grade.
This was an engineered, permitted project. The footings were 3′ wide and had to be buried up to 8 feet deep to meet the “7-feet-to-daylight” requirement.
This was a 500 sq. ft. (although there is a huge crawl space underneath – about 6′ tall at the back – that I use for storage.) structure with minor plumbing and drywall interior Not a nice, finished interior, to say the least – just fire-taped – you know, a garage.
It cost roughly $50K. A flat garage without all the footing work would have been about $25K, I’m told – which works out about right – the footing job was $25K. Framing labor was $7K. Lumber was $11K (lumber was expensive then). Electrical quote was $4,700, but my dad did that. $3K for concrete work other than footings, $2K for drywall. $7K for stucco.
Need to make sure any lot you buy is not considered an environmentally sensitive hillside. There are ways around it, but it’s a pain.
