The idea you're looking for is intensity--energy spread over an area. The further away you are from the source, the less you'll be exposed to because the total amount is spread over a larger area.
Generally to increase Intensity, you'd have to make the source bigger (number or size) or focus it (requires knowing the frequency/wavelength and making a lens with the right curvature--yurts are _very_ unlikely to have the right curvature for this).
The other important idea is constructive & destructive interference--if in sync, waves from separate sources will add together; exactly out of sync, they cancel each other out. Most evident with two audio speakers--if you move around you can find quiet and loud spots (dependent on frequency/wavelength, again).
The thing about a sensitivity to electromagnetic radiation--it could happen, but the typical EM radiation intensities aren't going to be very high. Sensitivity is also going to be highly dependent on frequency/wavelength of the EM radiation. Some frequencies are everywhere at relatively high intensity (radio; cell towers), some are everywhere but get absorbed by air or
readily (microwave; wifi) and don't travel very far. To get an idea of some of the stuff you're 'exposed' to everyday, see this
frequency allocation chart. There's also different visible/light frequencies, a low level of background ionizing radiation (x-ray, gamma ray, cosmic ray), and so forth.
An amusing way to test what frequency you're sensitive to--find the different sources of each frequency (airport radios? handheld radios? am or fm or amateur radio antennas? cell tower? home electronics? distritution wires and switching gear? fluorescent lights?). If you wanted to get very precise, find someone that can make small amounts of EM radiation at different frequencies/wavelengths and have them test you (like on a small patch of skin). Then you could figure out exactly what devices you need to avoid, what might focus/intensify any small amounts normally present (building materials/shapes; meteorological conditions perhaps? all depends on frequency/wavelength), exactly what you can do to shield yourselves (aluminized mylar in your clothes?) for 'everyday' life exposure. This would also rule out many confounding factors (particular chemicals in computer labs/server rooms, for instance).