I've had an all wool runner on my stairs for 12 years and absolutely love it. We have a large dog and two kids have grown up with this stair with no slipping issues. Wool is great for other reasons from an environmental aspect. There are several online sources that can educate you about wool carpets and it's appropriate applications.

Would you think of swapping the chairs to either side of the window and the sofa facing them on a larger softer more traditional pastel floor rug. I would add some greenery like a parlour Palm to the corner of the room in a traditional styled pot. You house looks just beautiful with all its lovely features. Chairs on an angle plus a coffee table in the middle

If there is a storage cupboard underneath the stairs, then I think its best to let go of the open risers. At the end of the day when it comes to stairs, I think you need to make simple decisions, don't complicate it. Sometimes spaces fuss over stairs and they can look great, but they are very impractical, expensive and dangerous. I think if you live in a house with no kids and no elderly, then you can lash out and go for something with more design risk. I think the timber stair profile shown in your picture looks great, and would work well with your vertical timber beam balustrade. However timber stairs can be noisy and quite slippery. If you are using carpet upstairs then you could consider running carpet all the way down the stairs. Don't do the half half thing. In order to finish the edge of the stairs neatly, I would edge the stairs with the plaster finish continuing from the cupboard wall, all the way up to the edge of the stairs and making an edge profile for the carpet to be neatly tucked into. By doing this you could still get the stepping silhouette which would look very cool. Then the beams could run off the plaster surface and not the edge of the carpet. Ultimately carpet may be annoying to have to vacuum, but it is a lot quieter, considerably cheaper and safer than timber stairs. Hope that helps. Good luck with it.

Hi. Does the carpet have a pattern that you need to allow for when cutting or is it solid colour? Also, I know you said stairway is standard, but standard can vary. It's best to measure, using a tape measure, the depth of the treads and the height of the riser and multiply that out. I would also recommend you consult the carpet supplier salesperson to calculate the amount required so you don't order to little or too much. If there is no pattern to consider, you can probably cut the 4m wide carpet into 5 strips. Hope this helps.