The over-riding reason appears to be is that he wants the land at that particular site and as part of the purchase deal is prepared to move the exchange equipment to another location. Yes it is possible but requires a lot of planning and co-operation of Openreach who would want to ensure that their approval is met. From memory they moved location for a couple of large exchanges within the past few years - the reason why they moved is coming up.
Thing is it could be
very complicated. BT/Openreach no longer own ~ 75% of the land and buildings where their exchanges are located. Circa 20* years ago, BT sold off several thousand of their exchanges to property management companies. It was a way for BT to release equity & raise capital to pay for 21CN and full fibre and back then they envisioned in ~20 years time there would no longer be a need for exchanges in every town. When they sold off the land, part of the deal was that BT would still be able to operate from the building for 20* years and they would pay rent on the property for as long as needed.
Bearing in mind that the vast majority of the properties sold were the smaller exchanges, its highly likely that the exchange you are interested in is owned by a property management company. Any of the exchanges BT do still own, you don't stand a cat in hells chance of being able to purchase The first step would surely be to find out who owns the land by searching Land Registry.
TBH I think this is going to be a pie in the sky project. The property management company who bought likely already have plans for the land and buildings. They've basically been sitting on the land unable to do anything with it until BT/Openreach are ready to move out. There's been a couple of cases where BT/Openreach failed to get a lease continuation and Openreach has had to relocate the exchange to a new building.
I did hear a few years ago that Openreach still intend moving out of ~5k* exchanges over the coming years. If you think about it FTTC & full fibre already operates out of Headend exchanges. Copper will also go as we move over to VoIP.
Theres also a sticking point due to OFCOMs insistence ~15* years ago that BT should allow other network operators access to their premises, so what happens now with LLU? The likes of Sky and TT still have live equipment in practically every single exchange and so Openreach cant just close down the exchange - not whilst there is still LLU MSANs in them. BT have already had to pay quite heavily on some exchanges and renegotiate terms with the property management company as leases have now started to expire and BT aren't is a position to be able to move out yet
Unless you have lots of cash to throw at what you want to do, I think its going to be nigh-on impossible. The current situation is a mess as it is. You have
- BT/Openreach haggling to extend leases they made 20yrs ago.
- Openreach knowing that they want to close down ~ 5k* of the exchanges asap.
- OFCOM insistence that any LLU obligations are met and access to the exchange for other operators.
- Property management companies wanting Openreach out so they can develop on the land they bought 20yrs ago
- Various delays. 20 years ago BT envisioned little need for copper by 2020. 21CN telephony voice upgrades abruptly halted ~2008
TBH because of the above points, I think the technical aspect of moving telephony equipment is the least of your worries. Much harder is going to be able to get the property management company to sell. Because of what I explained above, now is not the best time to be able to purchase the land. Many of the locations will likely have some sort of clause written in that the property management company cannot resell whilst BT/Openreach still have operating equipment in the premises.
Your first step would be to find out who owns the land, then you are going to need the legal expertise of a specialist conveyancer. IIRC most of them went to a large specialist property investment company who may sell if the price offered is attractive enough, but then again they may not be able to depending upon what sort of lease arrangement they negotiated with BT when they bought it 20 years ago. This is hardly likely to be something one man can do alone, it would require a whole team of many different specialists. Because of the complexity of the BT leases, its not the sort of thing anyone on a forum can advise you on.
Notes
*Typing from memory. So could be wrong with dates about how long ago and numbers of exchanges sold.
The names of BT & Openreach are used interchangeably depending on the timeline & Openreach did not come into being until after the leases were made. [Moderator edited for a typo fix.]