The first one is very generic there's no way to set heating type and it assumes you replace your phone! (mine's 8 years old now) it also assumes you live somewhere that needs air con etc. the second one is set up for the UK, giving the same info to both produced a result of 75% of the target for the second one (good result) and a 1.6 earths for the second.
Rocket Mass Heater Plans: Annex 6" L-shaped Bench by Ernie and Erica