That's a great question. I just want to add something to what Mr. Cousineau said.
When we calculate a project's net present value, avoided costs are calculated first. In this case, they amount to $2.6 million. Then we calculate the difference between the sale price of the current residence and the purchase price of the new residence. Here, the list price of the current residence was $3.9 million higher than the amount paid for the new residence. Finally, we update future savings at today's cost. Based on current practice, the calculation covers the next 20 years.
I don't have an exact breakdown—I can give you one if you like—but the monthly costs of the new residence add up to about $10,000, or $120,000 annually, whereas the costs of the previous residence amount to $240,000 annually, which explains the $115,000 in savings mentioned.