Are raised-heel trusses worth it?
Brian_Pettee
| Posted in General Questions on
Hello,
I am in Northern Utah and working with a local builder to do a semi-custom single story ranch home with a full basement. Specs are:
Zone 6B
2100 sq. ft. main level
9 ft. ceilings on main and basement
Standard OSB (taped)/Tyvek
LP Smartside
Blown in fiberglass
I requested a quote for 12″ raised-heel trusses and the quote came in at $4000. Does this sound accurate. I know there is increased cost for truss design, sheathing, siding etc. If this is accurate, does it make sense as a ROI energy efficiency-wise? Comfort-wise?
Thanks for any help!
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Brian, are you staying that including the raised heel cost an additional $4,000? Or the entire truss package is $4,000?
Trusses can vary depending upon pitch, span, snow loads, lumber grade, and whether or not piggy-backs are needed. I can't imagine that the raised heel feature would add much to the cost.
This would be additional costs. Seems like a lot to me but I am not a builder and I know labor and materials are super high right now. Perhaps the sub does not want to be bothered with the change?
That's absolutely insane. The average uncharge here is a few hundred bucks tops. There must be something else at play.
The $4,000 upcharge must be from your builder? This would reflect the added costs of labor and materials in raising the height of your building by a foot. If that's the case, I'd say it's reasonable and definitely worth it! If that's JUST the upcharge on your truss package, it's absurd. Find another truss guy.
Brian,
I am assuming a 2x6 wall? That is a bit weak for your climate, R-30 would be better with an R-60 ceiling. What is your air barrier detail and ACH50 target. I have been working with a couple of builders in UT building Net Zero homes. If you are getting roadblocks by your current builder choice, look around. Times are changing and progressive builders are out there and don't need hand holding through the process. Accept nothing less than the 12" energy heel with ventilation.
I should stay out of this but I think that may be a reasonable number. Lots more blocking and bracing. Trying to keep the bottom chord flush with top plates all the way around. I hated stepping over those trip hazard raised heals. Its usually 7" or 9" if you stack the top and bottom chords or use a 2*6 as one of the members. So its has as much room as the wall to insulate. If you want more insulation why not just use 2" eps as a baffle/vents. 12" not so terrible to work with but taller that that is miserable in my opinion. Talk nice to him and maybe you can get him to do it for a bit less. I am probably the only one left that thinks it is not worth it. Spend the money almost anywhere else. Its not a religion for me. No return on investment even at 3%. No noticeable improvement in comfort in my opinion.
Way too much money for that upgrade, 1/2 that at most, it is not that much additional work. Your builder needs to step out of the dark ages and into the real world of modern building.
Whats the real world dollar benefit for Brian? I am not going to do the math but does he save $4.00 a month.
What is the cost of chronic ice dams? This home is to be built in an area where ice dams are a real possibility. Dollars and cents don't always make sense when it comes to building. There is a clear path to a functioning roof system and it includes adequate insulation over the exterior walls along with ventilation in each rafter space.
Hundreds of thousands if not millions of homes built with out energy heals and no ice dams. My observations are in Minnesota. Totally agree with you on the ventilation.
20-30% of a typical home's heat loss is through the ceiling. It depends entirely on the design, of course, but not doing a raised heel might reduce that by 10%. 10% of 20% is 2%. So by not doing raised heels, you're paying on the order of 2%-3% extra on your heating bill. A typical heating bill in cold climates varies a lot but might average $2000. 2% of that is $40, 3% is $60. A lot more than $4, and a lot less than $4,000.
I believe your MN building code is different than the IRC that most of us use? In the IRC, for zone 6 the minimum required ceiling insulation is R-49. That can be reduced to R-38 if the insulation extends across the entire top plate. That's about 10" of cellulose, plus 1" to 1 1/2" for a ventilation baffle. So unless you have at least 11" heels, you can't meet code minimum standards. There is a provision in the IRC to reduce the ceiling insulation to R-30 over a total of 500 square feet. That still requires 9" heels. You could use spray foam at the eaves, if you don't care about the environment, and the costs would increase.
I always spec energy heels so I don't know how their cost compares to those without energy heels, but it's the same effort to build the truss, essentially the same effort to install them, and hardly any difference in material, aside from a couple extra rows of siding. So I don't believe the $4,000 number is fair.
Hi Michael, Its entirely possible that you over guesstimated the cost to heat for Brian by 50%.
If its $50.00 as you said we need to divide that by 12 months. That's a bit over $4 a month.
It's like 15 years since I built anything as a contractor so I am not up on code but does code still allow you to calculate instead of prescribing to meet energy code.
Addressing you third paragraph, Its not the same effort to build the trusses, not the same labor.
Take a look at the picture of energy heals on today's GBA Product guide, Working with zip wall R- sheathing. That's expensive.
I am making the argument that Brian should spend his money elsewhere.
The two things that change when the raised heels on trusses go over about 12" are the ease of standing them, and that in high seismic areas structural blocking between the trusses may be required. The cost of the additional sheathing and cladding to cover the heels is marginal.
Malcolm,
Good point on the bracing for seismic zones. All of the talk about payback for improved efficiency is based on current cheap energy. With what is going on today with the virus and financial market meltdown, an improved building envelope may be a good place for smart money.
I wouldn’t make design changes to your house based on the current virus scare, which will likely pass in a matter of weeks or months. Your house is going to be around for decades.
I would consider energy savings based on increased energy costs in the future, which is something that is very likely. That means that the same percentage of energy savings will save you a higher number of actual dollars for that same amount of saved energy in future years compared to today.
Bill
My thinking was more along the lines of cheaper money (lower loan rates) as a result of the virus. An improved building envelope would be less expensive due to lower carrying costs, possibly a good inflation hedge.
Interest rates are already at or near zero on an inflation adjusted basis. Have been for almost a decade.
>"I believe your MN building code is different than the IRC that most of us use? In the IRC, for zone 6 the minimum required ceiling insulation is R-49. "
Though based on the IRC 2o15, the amended Minnesota codes axed chapter 11, replacing it with Chapter 1322 of the Minnesota Energy Code:
https://www.revisor.mn.gov/rules/1322.0402/
Note that R49 is still code minimum everywhere in MN.
The prescriptive wall-R under MN code s lower than the IRC, but some of the bigger changes from the IRC in are the details found under section R402.2.8 Basement walls.
Utah code is also based on IRC 2015, prescribing R49 for roofs/attics state-wide, but also allows a whole house U/A alternative to prescriptive R values, which in decently designed homes can usually get away with lower attic-R than R49:
https://up.codes/viewer/utah/irc-2015/chapter/11/re-energy-efficiency#N1102.1.2
https://up.codes/viewer/utah/irc-2015/chapter/11/re-energy-efficiency#N1102.1.5
Dana, It’s an R49 with a 6” minimum energy heel in MN. They don't derate the missing insulation at roof edges as long as you have the minimum heel and it transitions to an R49 value. In WI you can skip R49 and do R38 if the full thickness extends to the outer edge of the top plate, which you could do with a 12”, otherwise you need R49 depth ASAP with the 7” heel.
Standard energy heel from a plant is around 7”, 2x4 bottom chord with the pitched 2x4 top chord on top of the bottom chord at the heel. Little sliver of wood shim fills the angled gap, you can of course get whatever you want.
$4k upcharge? Depends on the layout and roof style. Seems high, but it could be 100+ piece, hipsets with girders, coffered, vaults, trays whatever. If its a little 1600 SF flat ceiling ranch then it’s bonkers.
For reference in WI Ill pay around $3200 for 1600 SF house plus garage, structural gable ends, 1 girder, hangers, anchors, 1 valley set with a 7” “energy heel” in a standard L shape delivered. Ive paid many times that on larger complicated houses. No ice dams, if conditions are right maybe a couple inches at the edge for a bit then they melt off.
For $4k you'll most likely never get your money back, nor notice any difference. My own house has both 9” heels in some areas and by roof design some 18” heels, the 18” heel area has more exterior surface and glazing % and runs slightly cooler than 9” heel area. Not a simple answer except that $4k is likely better spent elsewhere.