Go with the lighter. Your space looks dark. Dog hair is the price of having furry friends. The lighter color will also work better with the introduction of leather chairs. Have you ever considered painting the room a warm white or lighter color? It would really make your fireplace a beautiful focal point and bring out the beautiful beams and wood detail.. Your current paint color causes it to recede into the wall.

This off topic, but I thought I’d mention it. I have a vintage caramel leather chair from pottery barn that I had near a window. It was a rich creamy caramel colour and the change was so gradual I didn’t notice it until several months later. The light really does a number on leather and areas where the light/sun hit the chair has lightened the leather a lot. Those parts are more a grayish caramel and I wish I’d noticed it sooner. I’ve moved the chair away from the windows but the damage is done. Just a heads up since you said you wanted to put your couch in front of the window.

Thank you for the suggestions everyone. We finally got our sofa delivered so I thought I would add photos of it in our space. Included in our lounge with some of the kitchen in the back ground so you can see the other colours in the room. Tan sofa, Blackbutt flooring, beige resin kitchen chairs teamed with concrete table with American oak legs and white kitchen. We will have white sheer curtains on the windows as well which will soften the area. Just waiting on the curtains to be ready. im reluctant to go “too light” with a rug because we have a young family not sure I can keep it clean. let me know what you think guys. Light grey is growing on me but still unsure :)

looks like your response landed right before mine! weird. can I ask, is your siding natural cedar, or is it painted brown (which is how it looks in the photo)? minimal does not necessarily mean it should be all one color. in fact, when it comes to window frames, that usually looks very weird unless it's done just right. imagine if you wore a light brown dress with skin tone tights and light brown shoes. or to put it a different way, this minimal all-brown house with a medium brown roof will look like a cardboard box. don't pick an odd color just because you can't afford what you want. either spring for black or very dark bronze (and cut something else from the budget), or get white vinyl. maybe choose white siding if you want it to blend in so much. I like this look: I know there don't have to be rules when it comes to house colors, and I'm not trying to sound super harsh here, but just being honest. still questioning it? ask your architect to give you color drawings with your choices.