Love the desk so back is to the wall and the front part of the desk (where your plans are) is facing the other wall with no windows. That eliminates the glare so you can open the blinds.
Then get some art/diplomas for the wall behind you. Maybe a TV screen in front of you- and a large tree in the corner and the book shelf in the other corner.
A colorful, graphic rug would add some life too.

I agree with all of the above and some artwork on the walls. Good luck!

Dima, think about what pleases you or naturally brightens your day. Then find ways to incorporate those little touches in your office.

It may be things like choosing a more decorative pencil cup, different colored folders (rather than the plain manila ones), or bringing in your favorite coffee mug. Sometimes the little things make an office feel more like your own space and bring a little extra comfort. Anything that adds some personality and does not look like it came from an office store warehouse will shake up the atmosphere. I would definitely suggest adding some artwork to your space. Art can go a long way at making an office feel lived-in and less empty.

If you're a visual person, you may want to add a wall calendar or a production chart of the current projects you're working on. Try finding some interesting art prints that have to do with your field, or see if you can paint another wall in your office as well.

Consider adding more stylish chairs in front of your desk, if that is an option. That might give it a more cozy feel and lessen the generic office atmosphere. I also see your plant - greenery is great in an office, but you may want to consider adding another tall plant near your plan table (on the blue wall).

You may even consider if moving things, or adding new systems would make your workflow more seamless. Of course, this depends on how much flexibility you have with your space. Could you add a couple hooks by the door for your hardhat, keys, and maybe a jacket?

These ideabooks might help spark some creativity:
https://www.houzz.com/magazine/guest-picks-the-inspired-office-stsetivw-vs~1583983
https://www.houzz.com/magazine/budget-decorator-10-tips-for-a-stylish-and-personal-home-office-stsetivw-vs~7178368

This would be a fun print to have on your blue wall. (Although, I would definitely suggest adding artwork with more color to liven up the other walls.)

http://www.art.com/products/p15693141723-sa-i6956799/andrea-costantini-spiral-staircase.htm?sOrig=CAT&sOrigID=1824&dimVals=1824&ui=A84BDC42CBE54EDAA21673ED76611C3C

I like the artwork, except that I'm lost on which would work for the office atmosphere, where we have stressfull days and boring days all in the same week. I have plenty of wall space and empty corners for tall plants. Would you suggest dark/light frame or frameless? Any suggestions?

If you want to keep the office more polished looking, I would go with framed pieces. I'd choose dark frames since you have light walls on 3 sides. Dark frames would also complement your dark desk, chair, bookshelf, and blinds.

However, if your office is a more laid back atmosphere, you could choose frameless canvas pieces. I would lean toward whichever style you prefer. This is your space where you'll be spending a lot of time.

On the type of artwork / atmosphere, I would again lean toward what interests you. If you prefer the technical details of your work, find pieces that center on interesting engineering feats in buildings. If you like the technical side, but you find yourself needing a mental break from the technical side of it, choose more abstract art that would give your brain some room to relax.

You really can't go wrong as long as it's something that you like and relate to. If they are pieces you can appreciate they'll work. On boring days, artwork you like will make your office a little more interesting to be in. On stressful days, viewing the art you prefer will give you a moment to stop, breathe, and appreciate the work before digging back in to business. But if you don't like a piece, then it's just stuff on the wall.

if youre interested in art i sell black and white pictures of vintage new york from the early 1900s that come in a wooden frame, padded down and glass casing. On new york times the same ones go for 475.00 with a frame and im doing them for 45. only cuz my secretary made a wrong order and om stuck with tons

The details look like a commercial building (ceiling, base, window). You may need OFFIZZ and not HOUZZ.

I agree with the first comment to flip the desk. keep client seating in the same location, but you would walk around part of that L, your back to the wall not the window. the computer would stay in the corner and if you are working on it would see someone coming in the room. I like my shelving close so would bring in a low unit to completely fill under the window or move that unit you have inside the door to under the window and fill in the rest of the space with new shelving (open or closed). doing that would move everything closer to the door and give you a feeling of more space. take advantage of the light and bring in more plants they help clean the air and give a homey welcoming feeling. I also love the colors of the room and would think about coordinating the chairs, they do kind of date the space. love the green chair keesee posted. agree you need something on the wall, one large picture that you love on the wall you now have the bookcase on because you will be looking at it every day. maybe do your credentials on the wall the door opens into. the tall bookcase could be moved to that wall. also - never have your back to the door, facing it puts you in a position of power and authority