Advantages of a One and a Half Story House?

[MJ]

Forgive me if this has been a past topic here, but I am wondering what are the real advantages of building a one and a half story versus a full two story house.  I think I read somewhere on here that a two story platform frame is actually easier to build.  Has anyone done an analysis of material cost and labor cost between the two (especially when dormers are used with the 1.5 story)?  How about a comparison from an energy saving standpoint (habitable space to building envelope ratio, etc.)?.  I know Christopher Alexander and other architectural thinkers advocate for a "sheltering roof", which would be a key feature of a 1.5 story.  I have also read arguments against a 1.5 story - see http://www.greenbuildingadvisor.com/blogs/dept/musings/martin-s-ten-rules-roof-design.  Any thoughts???

[Steve_B]

To each his own as they say... I loved the 1.5 story with the loft and the charm of that long lost art of building a house that way, but in my case, it seems easier and more reasonable for me to go the tw story route

Still working out the figures on materials for a two story house, but I am thinking it is going to cost a few dollars more to build then the 1.5.... a few dollars being 3k to 5k

More windows, more engineered floor joists, more 2x lumber, more interior walls.... but more room in return

Not including flooring, cabinets, lighting, and appliances... my estimate at doing all the labor myself on the 1.5 except for $3,000 set aside for an electrician, was coming in right about $23,000 which included the concrete slab cost as well

Still trying to work on an estimate for the two story right now.... someone else will answer this I am sure

[flyingvan]

   I've built two places now--the first is a one and a half story @714 sq ft and the other two story @716.  I did the 1 1/2 that way to deal with the slope and height restrictions.  The second one had the same sort of slope, but a much higher height limit, so made it two stories.
   If I made a chart of advantages/disadvantages, all the 'advantages' would be with the two story.  The foundation was 20x20 instead of 20x30.  The heat distribution is far superior.  It required much less materials---I'm going to ballpark guess it took 75% as much material as the 1 1/2. 
   So from a practical standpoint I'd pick the 2 story.   If you are building your own home though, the design you like best should weigh much higher, in my opinion

Thanks for posting the 10 rules of roof design link.  I disagree with his hatred of dormers, but still good info

[MJ]

Steve - By "long lost art of building that way", do you mean balloon framing?  It seems that 1.5 story wood frame buildings were facilitated by and become popular during the balloon framing era - especially when long straight, old growth studs were readily available.

Flyingvan - Were your materials savings realized from the smaller foundation (20x20 as opposed to 20x30) or was it something other?  I also assume your better heat distribution was a result of a square shape as opposed to retangular?

[flyingvan]

  Yes---the 20x30 footprint translates to 600 square feet of roof framing, more wall framing, sheer panel, longer romex.. The 20x20 is basically a cube and the fireplace and wall heater are in the center of the first floor---the heat radiates pretty even (the loft in the 1 1/2 gets pretty hot)  If you compare the volume of the structure to the exterior surface area, a cube is hard to beat (unless you want to live in a sphere)
   The perimeter foundation for the 1 1/2 translated to 120 linear feet (20x30 with a wall in the middle where the structure steps down) vs. 80 linear feet for the 2 story


So this one follows the slope.  I've got beams going every which way

And this one's the basic cube


So the framing was much more direct

  Plumbing runs were shorter, which not only saves materials but also gets the shower hot sooner. 

[lazair2]

Steve, are you estimating based on the 1-1/2story plans from this site? Any revisions? I am looking at doing the same. Where are you located?

[Don_P]

The way the building code looks at it, as soon as the rafters are not tied to the floor joists its a 2 story. The requirement for tieing the roof together at their bottoms or in the lower third of rafter height or a ridgebeam is required. There are some framing constraints as the second floor wall changes height across the range of 1" to 10'. If the wall is shorter than about 4' I'd use a ridgebeam. If the wall is taller than 5' I'd frame it with a raised tie. The appeal of a 10' balloon frame is it has a prescriptive, non engineered wall height in a greatroom and gives a foot or so of kneewall upstairs in the balloon framed area. But you won't get the tie high enough to clear headroom requirements in the 1"-4' portion of the height spectrum, I'd use a ridgebeam in that height range.

If I wanted to avoid the ridgebeam I'd make the kneewall 5' or taller, platform frame it on a full second floor and use a raised tie. Things just changed in the interior.

As a house get's tall and narrow in either direction, remember overturning become an issue, a reason to be well tied to a good massive foundation

[flyingvan]

That's a good point, and does offset some of the savings.  I had to sink ties into the foundation with rods going up through the stemwall to the first floor studs, and sheer transfer all over the place.  Those simpsons aren't cheap either

[Steve_B]

Steve - By "long lost art of building that way", do you mean balloon framing?  It seems that 1.5 story wood frame buildings were facilitated by and become popular during the balloon framing era - especially when long straight, old growth studs were readily available.

Flyingvan - Were your materials savings realized from the smaller foundation (20x20 as opposed to 20x30) or was it something other?  I also assume your better heat distribution was a result of a square shape as opposed to retangular?

Balloon framing, as well as the use of a loft like it is planned. Sometimes the simplest things make for the most charm as in the loft....

[Steve_B]

Steve, are you estimating based on the 1-1/2story plans from this site? Any revisions? I am looking at doing the same. Where are you located?

Yes, based on the 1.5 plan here from the site... I live in Columbia, SC and pretty much all prices for wood and trusses comes from builders first source

I've never built anything wood before, but prices seem very very reasonable here.... I know if I were back in jersey, the price would more then double in cost!!!

[Huge29]

Forgive me if this has been a past topic here, but I am wondering what are the real advantages of building a one and a half story versus a full two story house.  I think I read somewhere on here that a two story platform frame is actually easier to build.  Has anyone done an analysis of material cost and labor cost between the two (especially when dormers are used with the 1.5 story)?  How about a comparison from an energy saving standpoint (habitable space to building envelope ratio, etc.)?.  I know Christopher Alexander and other architectural thinkers advocate for a "sheltering roof", which would be a key feature of a 1.5 story.  I have also read arguments against a 1.5 story - see http://www.greenbuildingadvisor.com/blogs/dept/musings/martin-s-ten-rules-roof-design.  Any thoughts???

Thanks for the link!  He makes a lot of good points to consider in designing. 

[MJ]

Yes, reading that article led me to start this thread.  Lots of good ideas, but it seems not using dormers or even roof valleys would be very limiting!

[flyingvan]

Don't be afraid of valleys---just make sure the intersecting roof pitches are identical, and lace the shingles in the valleys and you won't have problems

[Don_P]

As we travelled around the country building one thing that changed depending on where we were, was valley detailing. Drive around and pay attention to what you see alot of and whether it is working. In some areas an open valley with exposed metal was thought to last longer as a glacier moved down the valley, I've seen the unseen pan under there 3' wide. I do the same thing with Ice and Water membrane. We sheath, run a 14" metal flashing up each valley with a well defined crease, this defines and reinforces the valley, it can be several pieces lapped to drain. Then the ice & water, then lap the main horizontal tarpaper from bottom. Weave if the pitches and material allow for best appearance. If the conditions require an open valley the membrane runs up each side of the exposed valley metal. If the pitches are dissimilar usually you'll run the main body of shingles through the valley first and cut the minor roof's shingles along the valley line. While driving you can usually spot everything, but pay attention to what you see the most of... the pros in the area know how to avoid callbacks. I don't agree with him entirely, his examples were good though, detailing a roof for nothing is expensive and asking for more trouble. You can do dumb things with dormers, jambing several close together concentrates snow and water between them and at least one side is shady. I've popped alot of dormers out of loft rooms and made them into nice spaces. It adds cost fast but it also adds space and interest.

[flyingvan]

   I'm a huge proponent of designing exactly what you think it should look like, then figure out the best way to do it....   I also put the membrane down first, but in our area here (hot summers, lots of pine needles)  I won't put in the metal flashing---I've fixed other people's roof leaks too often.  No matter how far back you put that flashing there's still a downhill pathway you create with a roof edge right where water flows.  Metal under shingles shortens their life span, and when pine needles pile up there they find their way under that edge of shingles.  If you line the valley with EPDM and lace (or weave, if you prefer) the shingles, being careful they fully embed and no nails in the valley, it's pretty foolproof.
   It's a little hard to describe the downhill pathway I'm talking about, but if you fold a piece of paper to make a mock-up, and imagine a line angling off downhill from the crease that is the valley, you'll see what I mean.  You tear off roofs like that and see a classic corrosion mark angling down that metal flashing to its edge, then the water slips underneath back to the valley.  If someone had a roof leak inside anywhere near a valley, and that valley had metal flashing, that's where I'd find the leak.  Ugly blops of Henry's would get them through the season and give them a few months to save up for a tear off and all new roof.   The roofers I learned from felt that the less metal under composite shingles, the better

Also some cheap insurance----if you cut some scrap wood and bridge the very bottom of the valley, when you lay your membrane down, install the felt, and lace the shingles, they have something solid to rest on where they bend into that valley.  Later when you're walking up that valley you don't tear anything (except maybe your achilles)  If you look carefully you can see the strip in the valley there...Also in my earlier reply on this thread you can see where I learned the mistake of dissimilar pitches on the 1 1/2 story build---the shingles don't weave 1:1.  If Don drove through our neighborhood he'd no doubt spot that flaw and I'd have to dole out some mea culpas and a beer.