First problem, getting the cable from the loft to the study.

Since ground floor of house was built in 1911 and first story in 1950, gamble on the cavity running all the way down.
Hole drilled in cavity wall in loft and in study. Lower string with torch on end. Spend days trying to locate torch.

With the aid of a dentists mirror, the string is discovered 1/2 inch to the left of the hole in the study wall.

Cable running along loft behind old water tank.

Just need to get some cable ties and clip cable to roof joists.

View back along loft. Bit cramped up here, those joists hurt when you walk into them.
Defunct galvanized water tank on the left... have to think of a use for that.

In fact there's rather a lot of extinct wiring and piping up here.

O.k. servers, patch panel and switch. Nestling comfortably beside chimney.

Just need to work out how to run the cabling through to the other rooms now.

Non-standard wiring. Basically here I'm running two network ports through each cat5e cable. (With one spare cable for future use)

This was experimental. I asked around everyone I could think of whether this would work and answers came back ranging from "Well I did it with a 10Mbs network" to "Don't be an idiot".

So I thought I'd try it out for the socket in the study. It appears to work just fine, I've done a simple benchmark on the connection and I can get a respectable error free 100MBs through each of the sockets simultaneously. So I'll leave it as is, and if I need to add an extra socket elsewhere where I run cable, I can do the same again.