What order do I need to do things in?

[Muffinbutton]

A couple of years ago we were granted planning permission for an extension to build over an existing single storey side extension (looks like converted garage but it isn't).

The new extension will be a bedroom and ensuite, with a continuation of the current pitched roof. They'll also be a bit of reconfiguration of existing rooms.

We're now in a position to take it further. What do we need to do next?

Is this the right order?

1. Structural engineer to look at site
2. More comprehensive technical plans drawn up
3. Get quotes from builders

All help appreciated. This is very new territory for me.

Anyone?

is your planning permission still valid? yes this is right order.

1. Structural engineer to look at site
2. More comprehensive technical plans drawn up
3. Get quotes from builders

though we did
0) Get ballpark figures from builders

1. Structural engineer to look at site
2. More comprehensive technical plans drawn up
3. Get quotes from builders

and the quote we recieved at 3) were like almost double of 0) !

Thank you. I'm not liking the sound of double the price though!

Planning is still valid till Jan 2020, so we've still got a bit of time to play with, but probably not a huge amount if we want to get a decent builder!