What are you typical utility bills in the Bay area ?
FWIW, for a 1600 square foot 4 bedroom on the peninsula, built in the 1950 with architecture that is basically the opposite of energy efficient well, lets just say if the Gas & Electric company executive was bribing builders to build houses in a certain way, theyd build em like this: black flat roof, huge windows, no attic, no insulation (except on the added bedroom) and only went to double-paned windows in the past 10 years since we moved in. OTOH, lowland San Mateo county weather is about as mild as one can hope for in the continental US year round never really that hot or cold. We pay about $300/month for electric and gas in the coldest/warmest months, about $200 in the more moderate ones. The gas/electric split varies, but its billed together. Except on a colder than average winter, the electric is pretty much always higher. This is high for this area, but Ive got a lot of electronic toys, many of them running 24/7, and the dryer is electric and kids get their clothes dirty a LOT faster than adults do. Water/sewer is about $50/month and doesnt vary much unless were out of town. OTOH, we pulled out the front lawn and dont bother to water behind the fence can be much, much worse if youve got a lot to irrigate. Also will be worse when the kids become teenagers. Garbage is $25/month but its billed quarterly.