A month after the conservation commission ordered the removal of a Chilmark house perched on an eroding bluff, the commission Wednesday heard plans for the home’s removal: the guest house is slated to come down immediately, with the main house dismantled in phases depending on the rate of erosion. The 650-square-foot summer home on Stonewall Beach, owned by Natalie Conroy, stood eight feet from a cliff in late February. Ms. Conroy applied to move the house nine and a half feet back from the bluff, an application the commission denied because it would encroach on wetlands. In the end, the commission ordered that the house be taken down, and asked for a plan to remove the structures within 30 days.

Tarja McGrail with Coastal Engineering Company outlined a three-phase plan for dismantling the home, with each phase triggered by how erosion has affected the top of the bank. Until the third phase, she said, the house would be safe to occupy

Part one would begin immediately upon receiving an order of conditions, and would include the removal of an existing guest house on the site. The guest house rests on wooden piles, she said, which would be left in place until erosion fully exposes the piles and they could be removed without further damaging the bank.

“All these measures are geared toward protecting the bank as long as possible every step of the way,” Ms. McGrail said.

Land left exposed by the guest house removal would be planted with vegetation to prevent any further erosion, and would create a bit of lawn. “One blessing about this whole thing, it still gives us land area to be able to enjoy,” Ms. Conroy said.

Other phase one projects include installation of a temporary sediment barrier and an above-ground sewage collection system tight tank.

Phase two will begin when the bank has eroded to expose the outermost piles supporting the main house. At that point, a portion of the house and deck closest to the ocean would be removed, and the remaining building and deck would be reduced in size to fit on a smaller framing system. The structure would be supported by two rows of three piles each. In this phase the remaining piles would be removed only when they are fully exposed.

The final phase will start when erosion reaches the face of the second row of piles for the main house. At that point, the house will be abandoned, the sewage tight tank will be pumped and removed from the site, and the existing house, support piles, pipes and utilities exposed by erosion will be removed. The land exposed by the house removal will be stabilized using native vegetation.

Commissioner Joan Malkin said she was concerned that the plan called for too much activity at the fragile site. “I think you are doing the best you can do, but I worry that what you are proposing is too much activity cumulatively for that area,” she said. Ms. McGrail said work done would be within the existing footprint of the buildings.

The commission asked Ms. McGrail to amend her plans for the removal to include some issues discussed, including stipulating the types of tools used — mostly hand tools, as well as a small Bobcat and a flatbed truck. Commissioners also asked for another site visit after phase one to monitor progress.

The board of health has to approve the installation of the tight tank, as does the Department of Environmental Protection.

“Very interesting proposal,” commissioner Candy Shweder said. “It gives you a little bit longer in your house.”