Beautiful place with a great location! Tons of potential... as for shutters, though this isn't a log cabin, maybe check out some log cabin shutters and windows. They might go nicely. Might also want to consider expanding the patio and/or a hangover porch?

As for firepit and/or gazebo - YES! The two can be very complimentary! Attached some pictures to hopefully get your creative juices flowing.

What a gorgeous setting. I can only offer generalities.
I'm not sure how you can enlarge that deck without cutting off the light to the basement windows. And I think the rear of the house is screaming for a deck at least as wide as the house and deep to accommodate an outdoor (built-in) grill and furniture. I see rustic materials (stone, wood) with some heft. Good luck on your project.

You have a perfect setting for a deck, paver patio, and pergola all in one design. I would have an outdoor living design done for your back yard.

Take a look at this project done a few years ago in the midwest, seems to deal with the same issues. Deck has different levels for eating / dining / cooking and a lower area for lounging / relaxing. A dry creek feature adds space between the house and deck to allow negative space for the windows, etc. Some metal and wood combos with sunbrella shade system. Just thought it would be good to share. Good luck!

Glass canopy or wood trellis with glass on top.

Board and Batten shutters would go great on your exterior on the first floor! There is not enough room to hang them on the second floor windows, as each shutter should measure out to half the size of the window.

Feel free to submit an image of your home using our Shutter Snapshot application to see what shutters would look like on your home before the actual installation. Choose your style and color, and we'll do the rest and submit the image back to you! http://www.timberlane.com/resource-center/shutter-snapshot/

Hi,
There is an easy way to decorate your landscape. Because you live up in the northern country, you need versatile furniture. I think the rolling bench is a good option; you could easily roll it to enjoy the sunlight through out the day and effortlessly store it when it’s raining or snowing.

Please find bellow the link of the website. Let me know what you think about it.
http://www.rollingbenches.com/

how about a large cape cod porch.

mcbmd3 has the best recommendations material is important. Could post pics out windows?

I see three levels.Your too high off ground at back door.

Spa at far left near pit on lowest ground. Is lake better viewed from that side?

View out window important, kitchen window there? Not blocked by structure. Build small deck here comming out back door and turning 90 degerees for BBQ area, rolling BBQ placed outside of kitchen window at 90 degree, but deck will not tuch the house, is built away from basement window below to allow more light. I like being able to use BBQ all year and keeping close to back door as possible is a big plus.

Sun an issue? Is shade needed? Gazebo or deck? Heres where it gets tricky

I would then extend the deck out from back door as a walkway out as far as you like from back doors, 4 feet wide walkway deck at end terminate with another small area for standing views.

Along this walk way the main deck would be built out to the left when looking at current picture, or to your right as you walk along the walkway. This deck would be one step down. A wide step say 12 feet across onto this main deck that should be at least 15 feet to 20 feet wide to acomdate furniture, guest etc....

So you would walk down the walkway turn right onto the main deck. Here you could place a firplace at the other end but facing this step.It would be almost aligned with the end of the house. This large taller stucture would not block any views from the house either. Anchored down here makes sense cause it is closer to the ground. This deck could be easily accessed from the other doorway near the end of the house by natural walkway. It also becomes a destination away from the house

This main deck would end at current fire pit in bottom left of 1st picture. The spa then could be placed further out from here on that lower ground level behind the fireplace. It could be surounded by natural planting, no deck, so as to stand alone felling like a natural pool in natural blending into the landscape. separate from the deck. The fireplace could act as buffer wall, screening the two areas here.Again easily accessed from the door near the end of the house.

Up by the house a utility area could be created between the 1st level deck at the kitchen window below this deck and at this door that exist at ground level for trash etc... This looks like the garage area?

Traffic flow and views all play a role and of corse fuction a key role in design. I think this design gets the activities area out to the lake but also keeping existing lake views from the house, Need pictureout windows, kitchen back door and far right window. It also keeps one basement window unobscure while leaving other basement window a small openning from building the deck 1st level away from the house.

Hope this gets you going on thought process. I toiled with my back yard for 5 years moving mock up structures around and figuring the underground electric, gas, drainage, and it works now. Others gave me input on the design too once I established the layout considering sitting views, flow of traffic, function of spaces, shade, sun angles, Las Vegas 104 today Sept 6th..

Update; your 4 steps above ground level. I would start walkway after the BBQ deck with one transition step down. I thought it wuld be more comfortable to walk straight out from back door to observation area without stepping down.

From this walkway you would need to transition three more steps down to get to ground level. It looks like with these three steps and the lenth of a 20 foot deck you would be about 5 feet from alignment with the end of your house. Staying in the footprint of the house.

And I would take all the other two trees down blocking the lakeview. The two at the shore line.