Q Loss (BTUs) = Surface area x (indoor - outdoor design temp) / Effective R-value*
*You have to take thermal bridging through studs into consideration - an R12 wall has a real thermal resistance value of less than R12.
The R value of basic wood double pane windows is around 1.7 if I remember correctly.
For air leakage:
Q sensible (Btus) = 1.09 x airflow CFMs x (indoor - outdoor design temp)
A blower door test is required to measure leakage.
I don't know the formula for latent heat loss off the top of my head.
Don't worry about passive solar heat gain for heating since the system has to be sized for design conditions. (No sunlight)
For making a template I recommend excel.
economic collapse is a certainty. debt based fiat currency monetary systems can never continue indefinitely because they require continuous creation of new debt to service the existing debt. in the absence of economical growth (which is always predicated on increased resource extraction rather than capital alone), this leads to massive inflation which destroys the currency.
your leaders can't fix this - they're corrupt and only exist to enrich themselves and their corporate friends.