I am lucky enough to be able to build a house on my future mother in laws land. I have not convinced my fiancee of this yet, but I want to build an underground house for us. I told her I would build a house above it later if she wanted, but we will see. Anyways, I am looking for personal stories,tips,experiences,etc from you guys. I have looked online alot but there isnt anything satisfying enough that I have found yet so I want more personal info. The things I am basically hung up on are; -Ventilation. I want to have two systems available. One manual/passive type and one mechanical/electric. I know alot about electronics and such so I have a system planned for the fans and such so that all of them are independently controlled with the ability to blow in both directions. Nothing fancy. Ducting/pipes,the fans, some switches all on a board with labels. That way I can adapt to any future issues like being smoked out or something. This also brings up another issue. Concealing air intakes and outlets. I am thinking PVC pipe will do right for ventilation needs. I think I could put the pieces right into the concrete walls before it dries and then just work with it when its all dry cutting and gluing to make it work right. I was thinking 10 inch wide. For fans, I was thinking about some of these linked below: http://www.horticulturesource.com/pr...oducts_id=4972 With a blower to pull air in and push air out at the end of the run if needed: Vortex Inline Fan - Garden.com -Plumbing/sewage. I was gonna try to build so that I used the hills/slope of the land to my advantage cause of gravity and all of that. I have NEVER dealt with sewage and wanted some input on gravity or low energy systems that are simple and durable. For water, I was going to bury a tank uphill and/or use the many small streams nearby via filtration. -General construction. My plan is to find a spot. Either flat or sloped land. If flat I will; Dig. Keep all passages and rooms narrow with alot of untouched earth for more support. Leave one foot spacing outside of where I plan the walls to be. Lay down one foot or so of stones of random sizes. Ideally, all small pebbles. Lay concrete slab for floor. Start building walls with wood for supprt and concrete as the finished material. The roof is a bit tricky, as are the ventilation specifications. Ideally I would want to run the vents far away from the bunker itself and hide them, but I do not know how to go about that effectively and most importantly, on a budget. So build roof, fill the one foot gap around bunker with ideally pebble stone and then cover with dirt. If the chosen area is sloped; I will dig a "step" of sorts into the hill and basically build several linked concrete boxes and cover them with dirt. Ventilation will be a tab easier as I can just make vents in the walls facing away from the hill high up out of reach. Same basic plan. Dig, pebble the bottom, pour slab, erect walls and roof, cover top with dirt and back wall outside with pebbles. I will use the french drain method as I think it is called. Long ditches filled with rocks and PVC pipe with holes and rocks inside to drain water away from the bunker. For the walls, I plan to use concrete, scrap steel I can find or buy cheap, and a strange idea I have. They sell this stuff that is metal pieces to put in the concrete to help reinforce it better. I am basically going to shred all of my spare electronics and wire to do the same thing on a budget. I dont know how effective it would be, but I have alot of crap to shred so it is worth a shot. Finally a use for my dozens of computer cases, hell yeah! I plan to cover the outside faces of the wall with roofing tar and then tarps for extra water and moisture protection of the concrete. -Electricity. I plan to roll with solar and generators. I basically want to build a separate connected room for the generator(s) and fuel storage. This room or one close will also probably house the ventilation system parts and the water/sewage pumps if needed. I also want to have power from the normal grid for use until I need the generators. As in; use the power until it isnt there anymore because of whatever reason. Maybe an old military diesel engine fashioned to create my power and maybe run it on biodiesel! That would be pretty awesome and worth the work/smell! I hear those deuce and a half engines can run on anything. Maybe one could be turned into a generator? I am not sure. -Heat. I was thinking a wood stove for a very backup method. Like when I am out of fuel. I think the earth, body heat, and the generator(s) will heat the place nicely. -Security. Guns and gun ports inside only for choke points and exterior door areas. I just purchased a Cypher industrial grade remote keyless door entry system. Essentially two boxes. One with the 8 button keypad and the other with the brains of it. You can choose ac or dc and what voltage it all runs on. Also some other spiffy extras. It is straight up sexy and will go awesome with a steel door of the DIY persuasion. This shelter is going to be a several year project not all at once. I need help from you guys to start planning so I can get materials and start building when the weather is better. Cheap/DIY is what I am going for here. While it is not a good idea to do things cheap when it comes to this, I am not an idiot and have alot of experience in some of the areas involved, just not all. I am pretty resourceful and can make something of nothing. So I would rather buy the parts for something than go for the commercially made equivalent. Also, MILITARY SURPLUS stuff is always a good recommendation to me!!!! Thanks in advance guys and gals. I look forward to getting some useful advice and will SURELY post pictures and keep you updated when stuff starts happening. Once I pick a spot to build and get advice on the ventilation and stuff I will be creating a 3D virtual model of the bunker before I start building. So that will be awesome!