12 Summit Lane offers 4 bedrooms and 3 baths with +/- 1749 SqFt of elegant living space in the Berkeley Hills. In addition, a +/- 596 SqFt detached loft-style studio accessory building with wood parquet floors, lath ceilings, a kitchenette, a full bath, a workstation, a mezzanine with a fireman's pole hand railing & 2nd washer & dryer enhances the total SqFt to +/-2,345 & is ideal for multi-generational living or potential passive income, subject to local rental regulations. The open concept living room has a striking fireplace, hardwood floors & glass doors that integrate indoor & outdoor living. The kitchen includes a new 5-burner stove, refrigerator, pantry, & skylight. The primary bedroom offers hardwood floors, serene views & an updated bath. A spiral staircase leads to a sanctuary of bonus space or 4th bedroom complete with its own full bath & direct access to the outside. The main washer & dryer have a sustainable design with an eco-friendly gray water system. This eco-friendly home with solar panels combines mid-century allure with modern amenities. Minutes from Tilden & UCB, it offers an escape while keeping city conveniences close.