The climate in your region will determine some of the details, but porches that are comfortable all year round have these six features:
1. Heating, ventilation, and air-conditioning duct connections to control temperature and humidity.
2. Insulation in the ceiling and in the floor (if the room is on a raised or crawlspace foundation) to help keep the space comfortable and lower energy costs.
3. Electric radiant heat to warm the floor (if the porch is built on a concrete slab). Radiant heat consists of heated wires or water-filled tubes set in the concrete, and it goes a long way in making a room cozy.
4. Dual-glazed windows with ultraviolet light reduction to help keep heating and cooling costs down and protect furnishings and fabrics from fading.
5. Window screens to admit breezes but repel bugs. A screened porch can be used during at least two seasons of the year.
6. Window coverings that can be lowered or raised to control sunlight and allow privacy.