I’d skip the idea of a built ins and open shelving on either end for a number of reasons and would hold off making a decision until your fireplace is completed. Complimenting mantle in same stain would be a good idea. It’s a small wall, close to a busy fireplace so it doesn’t need much and tv can be mounted or rest on cabinet/console

It seems you a recessed area that may work although it is not so deep. After your fireplace is done I would contact a custom cabinet maker to see if that could be done. I am so over seeing tv’s over consoles with an empty wall!

When planning your new space, all those obstacles must be taken into consideration. This is just one example of a more contemporary tv area. Make sure to choose a company that will design and build custom!

Cement ledge is the mantel?

Keep the rounded cornered cement mantel if you want built ins on the adjoining wall ... unless what you're doing is topping/wrapping the current mantel in the same rounded corner shape. A square cornered wood mantel would make wood built ins awkward.

How much wall width do you have between the window trim and that wall behind the tv? That is the maximum depth of your built ins for them to be practical.

Is the current height of your tv comfortable for viewing?

What kind of built ins do you want?

..... A wall to wall board at a comfortable height for your tv painted the same color as your wall? You could begin with only that board and have the option to add more later by putting a pair of horizontal 2"x4" boards beneath the ends of a 2"x4"x?' -- [ ? = wall width? ].

Or begin with a single board and add at least one middle shelf and a base shelf just above baseboard height beneath that original wall to wall board?

Or do you want floor to ceiling shelving?

Or do want a mantel height shelving unit?

Or do you want a center shelving unit the right height and width for your tv and then add a pair of matching shelving units on either side? either mantel top height or floor to ceiling?

If you have a center unit that is different from the pair on each side, it could be deeper. Do round the corners of the top of the center cabinet or shelving unit if you do that -- perhaps matching the existing concrete mantel?

I think the floating option would be the best in your situation..built-ins would be a challenge as the space is already so odd...and the shallow depth is so limiting for display...floating shelves could be a little deeper ...or even vary a little in depth...

I don't think this is the spot for built-ins. A general "rule" of thumb you might measure for and consider is to use a credenza that is at least 25% wider than the TV and 25% shorter than the width of the wall. That should look balanced. You might want to match the finish to the new mantel if possible.

Oh, wow! thanks for all the feed back! This space is a bit of a head scratcher... I think I like the idea of a shallow unit similar to the last image @lynartist sent... Thank you @decoenthusiaste for the 'rule of thumb' measurements! Very helpful!

@suezbell , I want to wrap the concrete mantel that is there now with the same wood as the shelves. I was thinking of having the new mantel work with the shelves. try to make look intentional? sigh... we'll see...

Thank everyone for the ideas and help!

My concern is the mantel and shelves "meeting" will be an odd transition; however, I suspect that those very shallow ridges as shelves on the wall will likely be an even worse visual -- as if they're the remains of shelves that have been broken off.. You could just add a wall unit:

https://www.hayneedle.com/product/manhattan-comfort-cabrini-theater-entertainment-center.cfm

@suezbell you are right, it is a tricky and odd transition... I am working with a designer and carpenter to help figure it out. Your points are valid!

The floating wall unit is a great idea!!!!! Thank you! I really like that idea!

Not a Pro.

Totally agree with above, make decision after fireplace is done.

The fireplace is what you want people to look at when they walk into the room. It's going to be an eye catcher.

Keep things simple.

I would just do a floating console on the wall and mount the tv. Should you ever desire a larger tv in your family room, there will be no issues.

More info :-) the first time we got a flat screen, I was horrified that it was too big for the room, it was 50 inches. My tv is now 65 inches! and I love watching a movie on it. Of course, husband wanted a larger tv.............and once you cave, they get larger lol