Extending broadband signal in old building

I have a friend who wishes to extend broadband from one end of the building to the other approximately 95 feet away and one floor up!
The present setup is BT BB with BT Hub3 in the ground floor at one end of the building. We have tried a Powerline solution but it did not work, possibly because of the electrical wiring and some 10inch thick walls. Plus the fact that the building is used by members of the public and it wouldn�t be safe to leave the AV HomePlugs in situ.
My suggestion is to run CAT 5e cable to the other end of the building and use NETGEAR Wireless-N 300 Modem Router DGN2200 to operate as a Wireless Access Point in conjunction with the BT Hub3.
The length of the building is 95feet plus twice the floor height of 9 feet, to the loft which is accessible to run a CAT 5e cable to the other end of the building, which means that the cable run would be approximately 115 or so feet.
I would welcome constructive advice, solutions and best hardware, on the best and inexpensive way to achieve this as it is for a charity and funds are limited. Thank you.
Floor plans can be seen here.
http://i1304.photobucket.com/albums/s524/scopio1/Gro...
http://i1304.photobucket.com/albums/s524/scopio1/Fir...

Other than time, CAT5e Ethernet will be the cheapest, and general rule is run two cables so that if one breaks you can easily swap over.

Cat5e infrastructure cabling will do 100m (300feet) with no problems, and can go further if you just used 100 Mbps (though books don't recommend)

So cable and a suitable socket on each end e.g. sockets like this (£5 for pair) on a standard wall box

On the wireless access point, while the DGN2200 can be reconfigured I'd only use it if on an incredibly limited budget.

Cheap 100m solid core cat5e cable £10

Punchdown tool to get the cable into the connectors on the faceplates £7

Some cable clips to hold cable to the wall and job done.

Thanks for that Mr Saffron most appreciated.

Thanks for that. Which other wireless access point would you recommend instead of the Netgear DGN2200?

One that actually is a wireless access point rather than a router with various tweaks done.

Something like this TP-LINK device at £20, which even supports power over ethernet, i.e. you can power it over an Ethernet cable, making it easy to locate in an optimum position to get the best coverage.

Its not the fastest wireless access point, but if I presume correctly they just have ADSL2+ this one will suffice and cope with FTTC too if they get it.

I'd get the Ethernet installed first and give the converted net gear a go first.

On the TP-Link if the loft space is accessible you might find the access point in the loft powered over the Ethernet is a perfect location.