“Planting a fairly dense row of deciduous trees to block the sun in warmer weather makes sense”
This is NOT recommended.
1. Deciduous trees have many branches that block sun all year round. A dense row is even worse. If you have existing adult trees at the construction site that may be of use, then trim all the lower branches that will block the winter sun, and leave only high branches that will block the summer sun.
2.Just be aware that large trees near houses are a common cause of death, injury, and property damage in storms from wind and or ice.
3. New plantings will take many, many years to get high enough to only block the summer sun, and meanwhile they will block winter sun.
I recommend landscaping that gradually slopes up in height on the southern side as it goes away from the building, such that no winter sun is ever blocked. A well designed permaculture garden landscape is of great benefit.
Using slightly extended roof overhangs, and one floor overhanging another is cheap and very effective.
The sun is lower on the horizon in winter and higher in summer. Planting deciduous trees to shelter a southern exposure in summer is a time-honored way of managing sun exposure and solar heat gain. So, if you want to recommend against it you’re certainly free to do so, but it goes against a lot of accumulated experience and wisdom.