I live in an old house that is essentially three buildings connected together - each section of the house is separated by stone walls 3 feet thick floor to roof, which poses a nightmare for WiFi signal.

I'm in the process of renovations and I'm working out what I'm doing on the fly, but I've essentially chased a cat7 cable from my bt router in a downstairs room up into the loft.  This started with the intention of running it all the way to the chimney with a plan for an outside WiFi connection (225 outdoor) on a separate SSID and relying on the little bt mesh discs to send the WiFi around in the house on the default router SSID. I have a 150mb connection which over 5ghz wifi in the same room as the router gives me download speeds of 140mb on the router's default SSID.

As I've done more research I've decided to swerve the little discs, install a Jetstream switch and Omada controller in the loft and I've run three wires to strategic points in the house to install two ceiling mounted 225 eaps and one wall mounted 225 eap and then run a separate cable from the loft switch up to the chimney to connect to the outdoor eap.

My objective is essentially to provide WiFi strong enough to stream on multiple TVs/phones/iPads etc, normal internet access and future proof my house to add in smart devices/other WiFi reliant devices in future wherever I want. I also like the convenience of seamless roaming from eap to eap from one SSID connection inside the house and then outside in the garden.

My electrician is installing a socket in the loft to power the switch.

Of course I should have planned various scenarios before the rennovation work started, but I'm learning as I go. Long story short the plaster work has finished so my window for running cables has passed.

I haven't yet bought the kit so I'm going on hope that my three internal eaps will give me the coverage I need, but if they don't then I'm trying to work out how I can add more. It's not a massive house; the specifications for the internal eap units tells me the distances I'm asking them to cover will be more than sufficient, but there will be 3ft thick walls and doors in the way.

Upstairs is easy as the switch will be in the loft so I can just run an additional cable through the ceiling and install a new ceiling mounted eap, but downstairs won't be easy without disruption.

Ironically the room I'm most concerned about is the room that the bt router and fttp modem is in which I use as an office. If worst came to worst I could just enable the WiFi on the bt router, but it'd be a shame to have to run 2 separate ssids and lose out on the seamless connection throughout the whole house.

Would the only way to add an additional eap be to run a new cable all the way from the Jetstream switch in the loft down through the house and into the room where I needed it to be, or would there be another option?

Could I for example plug an additional eap into the bt router directly and get the same benefit of running on the same SSID as the rest of the network? Or could I take a cable from the Poe out port on the 225 wall eap and run that in line to another eap and have that picked up by the network and controlled by the controller also?

Alternatively could I put the oc200 controller as the first device out of the router and use some kind of second switch next to the router to feed one eap and then also feed the switch in the loft to connect to the rest of the eaps?

im basically looking for the easiest, cheapest and least destructive solution to the problem if it arises.

Any ideas would be very welcome.

Thanks in advance.