The area of wooden suspended floor is about 35 square metres. According to page 290 of my book, the U-value of the floor is 0.7 W/m2/K, so the floor has a leakiness of about 25 W/K, which assuming an average temperature difference of 6 degrees, implies a conductive heat loss of 147 W (3.5 kWh/day). (The floor may also contribute some of the ventilation -leakiness of the house, but I'll neglect that.) The floor doesn't just lose heat, it also feels cold, and thus (a) affects quality of life, and (b) perhaps
The options in the calculator include lifestyle changes, and all sorts of technologies for saving energy and sourcing low-carbon energy. I would love to help Oxford crowd-source its own 2050 pathway , but there won't be time in this single lecture to do it; so here is the plan: I'll come back to Oxford in March 2015, and, with Mark Lynas and other celebrities at the Oxford Literary Festival , we will find out what pathway the Oxford audience would like to choose, to keep the lights on, have energy security,
You may be interested to see what pathways other cities chose, when they took on the "British Energy Challenge" - here are those cities' choices, and my reflections on the British Energy Challenge roadshows of 2013 and 2014 .