You could do something like this without the tree. Maybe a short lamppost or a birdbath, statuary, etc in the middle if you wanted. Even a mailbox would look good in the middle. The types of flowers/foliage you can plant there is determined by the amount of sun it gets. Does it get a lot of sun, or is it mostly shaded during the day?

I'm definitely the wrong person to comment on modern, I'm cottage all the way, lol. Still, what if you built a tall raised bed? Here's a couple of examples. They can be made from many different materials.

Need to know your climate zone. Really can't give suggestions without that information.

I prefer groundcover to mulch, for sure! The plants do too.

This is the front of the house

And for the climate zone it’s

It’s mostly shaded in the day

This is really a question for the Landscape Design forum, not the garden photo gallery. Try posting there for very specific landscaping advice

Grass that doesn't require cutting:

Mexican feather grass

.

Fesuce

Butterfly garden?

I think a single largish shrub or a narrow tree with some ground cover plants below might soften and improve the look of your house...unless you refuse to give up any of your window views.

I would do a simple look. I would plant a Burgundy leaf Japanese Maple on the left and over toward the right place a large gray black boulder of an unusual shape. Some landscape cloth and cover the remaining ground with small Japanese black flat stones. Very simple and modern. And no maintenance!! I'll see if I can find a photo.

The redish plant on the left is a Japanese Maple. They need cold winter, which I believe you have. This has a water feature which might not be good for your space but it has a nice bolder. I don't think you need many other plants either.

Interesting beds you could take ideas from. I like the irregular bed shape using the boulders as border pieces. You could use a weeping tree or shrub instead of the Japanese Maple if you wish as well. Weeping Mulberry or weeping Cotoneaster. check with your local nursery for plant material that would work best.

martinisunrise, the climate zone that K Lawrence asked about refers to your area's winter hardiness zone. This is something every gardener should be aware of, because plants are classified according to these hardiness zone designations. If a plant is not hardy in your zone, it will probably not survive a cold winter there. Looking at the map you posted, you are most likely in zone 6 or 7. You can check that by looking on the maps at this link: https://www.gardenia.net/guide/european-hardiness-zones

A golden conifer would add year round warmth to the scene and it would really pop in front of that red brick. There are a lot of different golden false cypress trees that do not get too large, at least not for a very long time. I have no idea what's available to you, but here is a sample to show you what I mean. This is a golden hinoki false cypress(chamaecyparis obtusa 'aurea'). I envision this surrounded by some short purple-flowering perennials like lavender.

For more of a modern touch we have great planters, our most popular for modern designs are rectangular planters and square planters especially in simple rock gardens. Or maybe one large pot centered in a rock garden. Our pots are frost proof so they are durable through tough winters.

With modern designs keep in mind simple, neat, and symmetrical.

You can look at more of our designs and pottery here: https://www.eyeofthedaygdc.com/ but have fun designing your garden!