The Breakdown: A Private Island

The Purchase
Though undeveloped New England islands come up for sale occasionally, Horse Island is the only one in Massachusetts now on the market (privateislandsonline.com/horseislandmass.htm). Located a few hundred feet off Briggs Harbor, the 3-acre landscape of cedars and wild blueberries last sold in 1956 for $5,000, as a Christmas gift from the buyer to his wife. Today the asking price has jumped to $750,000, which is less of a steal than you might think.

Permitting
In our regulation-heavy state, breathing is about the only thing you won’t need permission to do in your private paradise. First, you’ll need to lobby the local zoning board of appeals to make sure you can build on the property; if there isn’t a bridge or a causeway to your island, you won’t qualify for a permit without the board’s express consent. Before you put in a dock, the Department of Environmental Protection must approve; to trim the trees, you might need the okay of the local conservation commission.

Construction
Building a house in a place like Horse Island can cost anywhere from 25 to 40 percent more than it would on the mainland—and that’s not including seawalls and underwater extensions to the power grid. (Last year the owners of a close-to-shore island in Maine paid $100,000 just to lay power cables to the mainland.) Other unavoidable costs: a septic system to handle wastewater (around $40,000), and a well (around $10,000).

Transport
As you might imagine, hauling materials and equipment to an offshore site is a major undertaking. Though it’s possible to walk through the marsh to Horse Island at low tide, high tide requires a small boat or canoe. One way to transport cargo is by helicopter, which starts at $5,000 an hour—and that’s after an initial fee of anywhere from $8,000 to $50,000. For moving heavy-duty equipment like forklifts, excavators, and concrete trucks, you’ll need a barge.

Budget Boosters
If you’re willing to skimp on luxury, island habitation can be relatively reasonable. A 900-square-foot yurt can be shipped and built for just under $100,000 in five to six weeks. For power, a small wind turbine can be had for $10,000. Even your choice of a privy can pay dividends: Composting toilets use less than 3 ounces of water per flush, as opposed to the typical gallon and a half, and yield flowerbed-quality compost.