u/Boring-Ad-1553

A friend is about to buy his first house. It's a new build and there are multiple houses on the site with the same design. The developer installs an ASHP, but not solar. Some of the houses have the two sides of the roof oriented south/north and some are east/west. Which do you think is better? Keep in mind the biggest saving will probably come from supplying free energy for the heat pump in the winter.

Also it's a small two floor, 80 sq meters total house. How many panels do you think will fit?

The house is listed at 879 sq ft (about 82 m²). 2-bedroom semi-detached/end mews.