When finishing an attic, the biggest question is often how to regulate the temperature. Because attics are naturally prone to being the hottest space in the house during summer and the coldest space in the house during winter, having a working heating and cooling system is a must in a converted attic.
Using the Current HVAC System
If your home already has ducts running in the attic, the simple solution is to keep using the old system to pump treated air into the newly finished attic room. Consider whether the old system is powerful enough to cover new areas without losing efficiency, though. To find the answer, you can hire an inspector to inspect your HVAC system.
If the attic room will get any kind of frequent use, relying on the old system is not ideal. Most builders who construct new homes put in HVAC systems just powerful enough for the finished rooms. Therefore, the old system will likely be insufficient.
Using a Separate Portable Heater and Cooler
For the budget-conscious homeowner, the cheapest method for cooling and heating the renovated attic is to plug in a portable system to be used for that room only. This option is ideal if the finished attic is small and will not be used as a permanent living space.
This option is not ideal if the attic is to be used as a permanent living space, because the air conditioner would be loud and need to be turned off when not in use. It will also have to be turned on for a certain amount of time before the attic could be used, at least in the summer.
Installing an Attic Fan
Air leaks in the attic can cause energy bills to skyrocket. The sun beating down on the roof can heat the attic to such a degree as to heat up the rest of the home as well.
This problem can be compensated for by installing an attic fan. An attached thermostat would automatically turn the fan on and off according to the temperature settings you have selected.
Installing a Powerful New HVAC System
Another, more expensive, option is to buy a new, more powerful HVAC system to accommodate the new space. This decision would need to be made during the renovation process, so ductwork and wiring could be put in place.