Does staying in my house outside of building mode get me construction stone. I'm asking because up to now i would go banking to get more soft clay to make tabs. Now, I'm planning on training construction by making things on my workbench.

Just sit in your house outside of building mode. The rocks appear near the portal.

Don't forget you need to stay in your house for more than 1 minute before the rock appears... Banking and such will reset the timer.

 

The best way to do it is to simply alch or fletch arrows/bolts/darts near your portal. I can pretty much garantee that if you switch skill between rocks, both construction rocks will take less than 15 minutes total to gather.

I believe you need to be in your house for longer then a minute or so.

Best bet: Have your butler get you soft clay each time and just make tablets.

Have your butler un-note items and bank whatever finished products. (raw fish - cooked fish) or what you indeed said: Make items on workbench, works great to.

 

Getting in / going out slows you down.