Guides to building below grade in Boston

What a dig costs, which rules apply, and how to protect the building next door. Each guide cites its sources, so you can check them against your own site.

• Builders, developers, owners' engineers

  What underpinning and basement dig-outs cost in Boston

  Pit-and-pour ranges per pit, per foot of wall and for whole jobs, computed from our published price book, with what moves the number.

• Builders, architects, engineers

  Building below grade in Boston's GCOD (Article 32)

  What the Groundwater Conservation Overlay District asks of a basement lowering or new foundation, with an address check to see if your lot is in it.

• Builders, developers, engineers

  Permits for below-grade work in Boston

  Excavation, shoring, tiebacks under the street, dewatering and neighbor notice, in the order a project meets them, with who issues each one.

• Owners and condo boards next to a dig, and their builders

  Your neighbor is excavating: what to ask for

  What to ask the builder for in writing, which signs matter, and who to call. With a printable checklist.