5 to 6 months from permits to completion on spec. houses & as long as 7 months on custom-built homes.  This is a factor you need to weigh in on whether you want to build, as you need a place to live till completion.  Some folks do NOT want to be the owner of 2 homes.  This from the 2012 Survey of Construction (SOC) from the Census Bureau.  Spaces are similar with 2,000 square foot homes to 3,000 sf homes.  Bedroom space accounts for just under 29% of floor space in new homes, irrespective of overall size of the homes.  Bathroom space is allotted 12.3% of total floor area on average with more space allocated larger homes.  All this from the National Association of Home Builders.  Part 2 coming.