No, they are not dado rails but the first bits of wood affixed to the walls for the start of baseboard construction.
As can readily be seen, one of the problems I have is the water heater for the new bathroom (next door to the left). Slap bang where my new layout needs to be. More on this later.

Research was still being done along with purchasing rail and stock. I had decided to go with OO gauge and DCC. Track was going to be Peco 100 streamline and I ordered numerous amounts of second hand items. Much need cleaning as it had previously been on old layouts but that is part of the fun - isn't it?
I made my own radius curve templates. I am fortunate to have a fully equipped woodwork shop just outside.

The construction began in earnest.

I wanted to incorporate a full circuit of track which led to issues of access not just for me but also to be able to clean and maintain the window.

The next picture shows the humble beginnings of my layout. I can't seem to get the images in the right place but bear with me.