If house open to full amount of light that reaches each exposure north would be best, unless you are planting kinds that would enjoy the heat from a sunny wall or cannot take full shade. Choosing the shaded exposure is because what damages broad-leaved evergreens during frozen periods is sun reaching them when they are frozen.

Yes, it really does depend upon the shrub you are talking about. That may be why it sounds conflicting.

For example, camellias do better up here in Western and Northern exposures for the reasons bboy mentioned. OTOH, heat-loving palms would do better in a southern exposure microclimate.

hmmmmm ....

in my z5 .. near ann arbor mi .. the prevailing winter wind is from the NW ...

ergo ... a zone pusher would go on the SE [ or the east side of the structure .... OUT OF WINTER WIND ...

in my zone.. its not the temps as much as the freeze drying effect of winter winds.. especially if the plant warms in winter sun ... and the warmer part of the winter sun day.. would be the west side of the house ...

so find out the prevalent winds in your z7 jimmy ...

ken

It does depend on the plant. Here I have those same NW winter winds, but a Japanese Maple overwinters better on the north side of a building. Why? Because in spring it takes longer for bud break and thus is less susceptible to late freezes.

tj