Cooling/heating costs 1 story vs 2 story house

[Leros]

I'm looking at several of houses around 1300-1600 sqft. A couple of them are double story and the rest are single story.

The two story houses are roughly evenly split upstairs and downstairs. How much extra in terms of heating and cooling costs am I looking at for a two story vs a single story house?

 

[DrPizza]

All else being equal (same square footage, same thickness of insulation in walls, same square inches of windows, etc.), the two story house will be cheaper to heat and cool - less surface area for the same volume.

However, all else won't be equal. An important consideration is the attic insulation. Also, note that the two story, with same square footage, would have a smaller attic - cheaper to add insulation. The downside is, it'll also have a smaller basement.

 

[BoberFett]

The size of the house makes less of a difference than the age and building materials/insulation. Compare our old home and new home:

Current home:
Built: 2002
Foundation: ~1500sqft
Total sq ft: ~3800sqft

Old Home
Built: 1922
Foundation: ~700sqft
Total sq ft: ~1800sqft

It costs half as much to heat the new one.

 

[Leros]

Hmm, I figured a 2 story house would be more expensive. In the summer you're going to fight to cool the second story as heat rises. In the winter you're going to be fighting to heat the first story as heat rises. Although I guess you would adjust the vents accordingly.

 

[Cyco]

I'm currently in a 1 story house, my last house was 2 story. Taking into consideration my current house is about 800 square feet less than my last one, my electric/gas bills went down to about half in the 1 story house.

 

[postmortemIA]

two story should be worse - it is impossible to cool down second floor in summer without having first floor being unnecessary too cold

 

[Leros]

Any more thoughts. I'm getting both answers in this thread.

Keep in mind, I live in Austin where its hot in the summer and not terribly cold in winter.

 

[ElFenix]

Hmm, I figured a 2 story house would be more expensive. In the summer you're going to fight to cool the second story as heat rises. In the winter you're going to be fighting to heat the first story as heat rises. Although I guess you would adjust the vents accordingly.

this is why 2 story houses should always have the floors be on separate units.

 

[NetWareHead]

I've always had 2 story houses and the most important thing is to have separate heating and cooling zones for the upstairs and downstairs levels.

 

[Leros]

Are separate zones different than separate units?

 

[bignateyk]

Are separate zones different than separate units?

Some units can do multiple zones. That way you can have the upstairs on its own zone so that you can control the temperature independently and not end up with a roasting upstairs in the winter and a frigid downstairs in the summer.