How large does this tree need to be?

How close to the pavers will it be?

Are the pavers just going to be set in place or paved in?

The tree will be maybe a foot away from the pavers. Yes they are professionally set in I just don't want any tree roots uplifting them. Something 10-20 feet tall would be good, although even taller would be great!

You want a small tree like a dogwood (either Cornus kousa or C. florida), a redbud, or a Viburnum prunifolium. None of those is likely to lift pavers. (BTW, a 10 foot tall plant is a shrub, not a tree.)

A foot from the pavers is pretty close.

The good news is even a concrete driveway does not last forever, 20, 30, 40, MAYBE 50 years? If you plant a tree by one which causes A, 1, crack in 20 is there really much loss?

Redbud is a fast growing tree around here, rivals Metasequoia when young. Then poof, someplace around 15 - 20 feet they flatten out at the top and try for a round flat canopy and seem to stay near the same height till death. Maybe they get taller in your neighborhood?

The fu fu fancy colored leaf redbuds I'm not sure I ever have seen an old example of. They seem to struggle with establishment but sure are attention getters.

Here is a Photo of the area. I would pull out that hydrangea and maybe the boxwood. As you can see it is a very tight space and not much room between the mulch area and the fence. My neighbor used to have a nice tree in their yard but unfortunately pulled it out and exposed all their windows facing my backyard. I just want to cover up their windows and the fence is def not doing the job. It's a little annoying because they have more room on their side but pulled out all their trees.

Ken, I am totally with you on this. This situation doesn't seem to call for a large shrub or small tree but a nifty screen.

The photo suggests to reduce the lawn for planting. Or do you actually use the lawn?

We have 2 teens so they do use the lawn somewhat. If I put a tree on the lawn it will cut the yard in half which I guess wouldn't be the end of the world.

I would not plant a tree within 1' from the pavers, no tree would like it, apart from any concerns for the pavers. But you do have a quite usable strip of lawn, the space constraint is not really that bad.

If you want a privacy screen for the garden, you could go for a hedge along the fence. The example in photo #1 below shows fast growing arborvitae, that you don't have to top for an even taller screen. The hedge will still take time to grow, though. You could get instant privacy for the patio as in photo #2 below.

Just an FYI perhaps. I am fascinated with bamboo and found this: BAMBOO BOB - Morristown, New Jersey - BAMBOO LIKES/DISLIKES.

You could also get some of those big containers (around the size of the half-barrels they have at Lowe's/Home Despot) and plant some hardy tall-growers, like the well-behaved perennial grasses, or just about anything hardy.