When I register a sensor I am asked to enter the elevation value. What should I enter there: the absolute elevation from zero ocean level or the height of the building? What is the unit you expect?
Hi @tbsprs! The expected unit is METERS and you should enter the height above sea level. Anyway, I would ask my colleges about it but i have always understood this! Best. 
@aitoraloa Can you recommend good online sources for finding out what the above sea level height is for a certain location?
@tbsprs: I guess this website should do the job: http://www.daftlogic.com/sandbox-google-maps-find-altitude.htm You can use directly the number you get when drop the marker or add the elevation of your location to it if you live a on a tall building. I hope this helps. Best.
Thanks. I added the elevation in metres and added the height of the building.