Sketching a Tea House with watercolours

I wanted to try a new watercolour sketchbook I bought recently for my plein-air painting. I did a simple sketch this time with my lightweight Holbein set in a style similar to concept-art works found in Studio Ghibli art-books. I painted this based on a photo of a tea house located in a Japanese garden belonging to a hotel located near my house (It’s a shame I can not paint there). You can see the painting process in the making-of video but to make things short I did not like how the paper worked with the