Height above sea level

[alextwo]

How can I calculate the height above sea level of a certain place?

[Maudlettice]

Apologies. I thought you were the simple duck, Daft Wader.

[chesa]

Is the reference for height measurement for K2 and Everest is sea level or base of the peak?

[Wet feet]

Is there any way, other than through using maps, string, duck tape, theodolites and sealing wax, and without gps, altimeter, a personal satellite, dead inertial reckoning or wellington boots, that I can find out if my house will be flooded if Hurricane Ivan eventually arrives in Kent? For example, are there data for mean height above sea level for post codes in the UK? Kent is a long way from Everest and K2, but a lot closer to Newlyn Pier. I am currently enquiring about the cost of sand bags in Homebase, although they'll have to be quick as they're a long way down the hill from here...I have 'O' level maths and thought I understood Pythagoras' theorem. Cheers