Hi @keithp,
Thank you for posting. Your best bet would be to place an order. Once the order is in place and all the checks are done you'll get a better indication of how long that activation will take.
I suspect that you'll need an engineer if there hasn't been a working service at that address in the last 17 years. Depending on the engineer's availability you should be able to get an appointment in around 2 weeks of the order being placed.
All of that is a best guess, the only way we will know for sure is when the order is placed.
Thanks,
Paddy