Crape myrtle trimming help

OK. I've read enough to know that pruning a crape myrtle is a personal thing.
We are moving into a new home soon that has 3 beautiful lavender myrtles and I'd like ideas about how to trim them up (they look ragged to me and are too close to the roof for my husband's liking). The neighborhood has several of these and most of them are trimmed up tree-like--- with a full canopy but bare stem/trunk. I think that looks nice, but is it OK for the tree? And, if it is OK, what is the best way to do it. It is quite hot here now, and I also wonder about trimming in the summer. Is it OK now or best in the fall?
Also, can anyone identify the variety of these?
Thanks for any advice...
Wendy

One of the other ones...

Neil Sperry's Gardens July/August magazine has an article on crape mrytles. His advice is to prune after the leaves have fallen off. His article is about red crape mrytles, but the advice applies regardless of color. He also divides the crape mrytles into groups by size. You could be dealing with an overgrown semi-dwarf variety (from 4 to 12 feet tall) or a tree sized variety (Over 12 feet tall). If you have some neighbors with the identical crape mrytle, ask them for the variety name. That way you know what you are dealing with.

A small amount of pruning is not going to have a large impact on the plant and it's ability to bloom, but severe pruning will result in excess leafy growth and will delay bloom for several to many years.

I think you are dealing with a tree sized variety and severe pruning would be required to bring it down to the point where it won't damage the roof. Have you considered waiting until winter and transplanting them to a different location.

I wish I could transplant them, but I don't think they would fare well with our windy area and our wide open backyard.
I wonder if it would be OK to lightly prune around the base where it is quite ragged looking to me. I think it would be best to wait until winter to do more pruning or anything-- but I don't know if the leaves will shed or not in the winter (our winters avgerage 50-60 degrees). I think the wait and see method will be best for now.
Thanks for the info from Sperry. I'm off to look it up online.
-Wendy

Wendy, I prune my crepe myrtles all the time and it doesn't seem to bother them. I would go ahead and do the pruning around the base now and then prune some after they bloom. You probably won't see a big loss of leaves if it doesn't freeze there. Jenny

crepes transplant very well no matter what size, just try to get plenty of rootball..you can cut them back late winter or early spring...........i trim the seed off after first flowering...they will sometimes bloom a second time..........this pic is of a plant that was cut to 18 inches and transplanted at the age of 30 yrs.......40 now