Ability to build facilities...

[Noble713]

# of facilites depends on two things:
1. Planet size
2. Whether the atmosphere is breathable for the colonists

Domed colonies have 1/5 the facilites of an undomed colony.

Plant Size/Domed/Undomed

Tiny/1/5
Small/2/10
Medium/3/15
Large/4/20
Huge/5/25

If a colony is domed, you can increase the number of available facilites through one of two ways:

1. Bring in people from a race that can breathe the atmosphere, and remove the old race.
2. Build an atmosphere converter and change the atmosphere to one the population can breathe.

I'm not certain, but I think Climate Control facilities only affect the conditions of a planet. The condition affects the population's reproduction rate but not much else.