Hi @VanessaL, There appears to be enough depth under the lips of the stair treads to add timber boards across the openings. I'd suggest using DAR Pine ...

This certainly could be a D.I.Y. project @VanessaL, but that comes down to your skillset and what you're envisaging. Is that some type of polycarbo ...

Hi @VanessaL. As there is no functional space left around the sink I would cut some laminated chipboard to fit the profile of the sink and screw i ...

Cutting doors to fit around the sink is in jigsaw or scroll saw territory, I own a jigsaw and I would want some practice first before taking on a job ...