I'm not sure what you mean by only 4 inches of space? You can't really do a built in on the right side of the fireplace unless you cover the window or make it narrower than the wall space there.

I think my hearth is about a foot off the ground or so. Mine might be an additional brick course. I know when we have lots of people over some occasionally use it to sit on.

Is the gas line just left of the fireplace? It looks like the knob to turn the gas on/off is there. From what I can see you need to be able to access the knob.

Typically when one has the brick stacked as you do the mantel sits on top of it. A talented carpenter could build a mantel to enclose the stacked bricks.

are you in love w/the brick? If you're not, you could fir it out and do something different on it. another tile, stone or even a wood. By doing that, you'll create another 6" of depth so you can have your built in's

examples

fir it and apply cement board (or, you could complete skim coat the brick w/mortar)

do a diff stone,,,maybe do a wall treatment like this, with consoles.

or a place for the tv

here's one they did w/wood

I love this look. fir it out and apply these planks of walnut. gorgeous

maybe you just do some benches on the side

if you just paint the brick, you could do thin shelves.

Or, along side the brick on the sides, use a thicker molding that would allow you to do shelves that come further out

these are shallow built ins. but see the side trim and how they stick out past the fireplace? you could do this

or, just paint the brick, wood molding, and no shelves. here they did a tongue and groove treatment

none of these are especially difficult or expensive. if you can do some DIY, you can do any of these yourself

@rrah I hadn't noticed that the window would be impeded on the right side. You are correct. Built-in could not be deep anyway. I like the idea of using the FP hearth as a mantle. (we are from Florida so having, not one but two, fireplaces is asking me to think of ideas I'm not used to making.

@Beth H. : Any refacing to the brick will have to wait until after this initial phase of reconstruction, I just want to be able to move in and the contractor is just putting the basics in (walls, bathrooms, flooring, lights, etc). I'm happy to see the ideas of your pics - because having a future plan will probably influence the tone of the room as a whole. There's a kitchenette that is on the other side of the room - don't want them to clash - and I'm already worried about paint color picks

looks good! what are you planning to put on the sides?

I get some nice art to hang above the mantle, and do some shelving like they have here

These would be pretty easy to recreate.

tried to photoshop two ideas. right side is regular open shelving.

can you DIY something like this? there's a tutorial under the pic

https://thediyplaybook.com/white-built-ins-around-the-fireplace/

(if you're putting a console of some sort under that tv, it would look a lot better if you lowered it.

HI, Beth,

For now, I plan on putting a small cabinet/lamp on the left side of the FP. The window on the right is (almost) to the wall and I can't put in symmetrical shelving. I'm still playing with it.

That open door to the left of the FP is a windowless bonus room that we are arguing over what to place into it. (gym, craft room, extra bed)

Good point about the TV height - I have a tall cabinet that I was going to put there and we thought it seemed better higher; now, I don't know. I'll have to look at it when we are moved in.

Thanks for the advice.

Md