Extension - remove existing render?

[nickjb]

The current house is rough rendered. Where the single storey extension is going should I remove the render:
1. Where the new walls join the house using crocodile wall starters
2. Where the timber plate for the joists fixes to the wall
3. every where else (which will be plastered/dry lined)

 

[noseall]

Remove the render where you make direct connections.

It may be prudent to remove where plastering but a lot will depend upon how tight the render is, how textured, whether it is painted etc.

We once left some render that had very small stone chips as it was a tight as. We were doing more damage trying to remove it.