Build your property (partially) underground? Like this http://www.trendir.com/house-design/grass-roofed-home-built-into-slope-uses-hillside-for-cooling.html htt

Build your property (partially) underground? Like this http://www.trendir.com/house-design/grass-roofed-home-built-into-slope-uses-hillside-for-cooling.html http://www.trendir.com/house-design/grass-roofed-home-built-... or similar. You'd need to deal with waste heat somehow for the infrared signature not to look suspicious. And ground-penetrating RADAR would pick you up as well, I expect.