Blissfully sparse inside and out, this treehouse-cabin was completed in a single weekend by its owners, who, at the time, were amateurs in their trade. Submerged in surrounding forestry, Half-Tree ...

Photo: Concierge Auctions A soaker tub inside the treehouse. Photo: Concierge Auctions The treehouse is an A-frame design.

Microsoft's Redmond headquarters recently unveiled its latest perk: tree houses. The campus is surrounded ... There's Wi-Fi and electricity. It has an outdoor gas fireplace to keep warm since ...