Just came across this thread. A few years ago needed emergency power for an oxygen generator for elderly family member. Ended up doing the whole house on the cheap. Bought a slightly used 13K portable generator for $400 of web. Got an outdoor transfer switch and had it wired in by electrician friend and checked by power company. The generator went in a modified plastic garbage can shed on a block foundation. The shed has fixed louvers in one end and in the doors. The other end has a large fan and louvers that open when the fan is on. The battery is kept on trickle charge with a small solar panel on the shed. The muffler meshes well with a vent dryer outlet on the back of the shed and the cable is plugged in and coiled inside the shed, ready to plug into the transfer switch. I test on load a couple of times a year and it always starts right up. Turn off all the circuit breakers and turn on what we need. Can run the furnace fans, microwave, refrigerator, TV and lights, if we only use the ones in the rooms we occupy. Have not tried either of the two central A/C units we have, but I believe the starting load level of the generator will even handle the smaller of the two units. Love the convenience of no extension cords to a portable generator to plug and unplug. First time I used it, a couple of neighbors wanted to know why our house was the only one in our development with the lights on!
The whole thing cost me about $900 and a bit of labor. Have used it twice, but both outages were in terms of hours, not days. Looks good and works good. Videos for similar setups can be found on the net.