New build framing question

[PT Doc]

I am always surprised at the vast bank of knowledge that lives on gj. Maybe someone can take a best guess on this question.

3450 sq ft 2 story home. Current plans show 2x4 construction in 95% of exterior walls. If architectural plans were modified, what would be a reasonable guess as to the ADDED cost from changing the exteriors walls to 2x6. Walls were netted 2x4 with blown in insulation. New 2x6 walls would be the same insulation.

Just looking for a best guess based on your experience. Thanks for the help.

 

[kd3pc]

framing materials alone will likely cause a 25-30% bump. All the sills, plates and such will have to be upgraded to play well with the walls....really can't do one with out the other. The 2x6 are substantially more, than 2x4 here in middle TN.

Double the amount of blown in insulation (and I would change that if I were you, as most blown in settles and you will end up with cold spots on the tops of the finished walls. AS 2x6 is almost twice as deep as 2x4.

Measurements for all fixtures will need to be reset, as well as clearances of doors and such to those fixtures. You don't think about it, but look at your home now and add those inches to already close by walls, fixtures, etc - added cost by architect TBD. In VA, that process would start at $2K and go up depending on hours to recalculate and change.

Window and door trim are more expensive, especially if you use wood or clear trim, as opposed to pieced together/resin stuff.

Others will chime in, perhaps some in your area.

 

[p_mori7]

 

[holdover]

go to the local lumber yard and price the difference between a 2X4 and a 2X 6 for your answer also the difference for a 2X4 X 12 or 16 to a 2X6 X 12/16 for your plates, you are also only talking outside walls here. Price out the insulation as well, stay away from blown in in the walls, if you don't think it settles take a thermo image gun to a house that has it.. All doors and windows are made either way, just a slight difference for 2X6 When looked at the overall cost of the house it is small change. The positive is you start with at least R19+ as opposed to R13+ for 2X4. I have not built a 2X4 outside wall house here in VA in over 30 years, years ago many power companies will not hook up power to a new construction home framed with 2X4, Duke Power in NC was one of them when I built a house down there in the late 70s, it had to be 2X6 outside walls. It can get could out there in Denver. You will save energy both summer and winter. It is like someone telling you that a front wheel drive vehicle will go in the deep snow as good as a 4WD, no way.

 

[7echo]

Look up 'advanced framing', here are some links to start...

http://www.buildingscience.com/documents/insights/bsi-030-advanced-framing

http://energy.gov/energysaver/articles/advanced-house-framing

http://www.greenbuildingadvisor.com/blogs/dept/musings/pros-and-cons-advanced-framing

 

[Zeke]

Pretty simple math here. The labor stays the same. Buy the lumber.

 

[PT Doc]

Pretty simple math here. The labor stays the same. Buy the lumber.

Sure Zeke, it's simple math. Get detailed drawings and count each stud. Call insulation company and ask the right questions. But that is why I was asking for a best guess, hoping someone working in framing would read this.

Basic math: a 2x6 stud is 57% wider. The quick check on hd shows a 56.5% increase in price. I thought that was pretty amazing. Since the cavity is 57% deeper there will be 57% more insulation. Headers will need to be increased as well. Window trim finishing will require more material as well. A few inches lost on each wall only becomes an issue in a few areas such as a powder bath in the corner of the house but there are inches to loose since it's a 3500 sq ft house.

This was more of a I wonder what it would cost question. Thanks

 

[PT Doc]

go to the local lumber yard and price the difference between a 2X4 and a 2X 6 for your answer also the difference for a 2X4 X 12 or 16 to a 2X6 X 12/16 for your plates, you are also only talking outside walls here. Price out the insulation as well, stay away from blown in in the walls, if you don't think it settles take a thermo image gun to a house that has it.. All doors and windows are made either way, just a slight difference for 2X6 When looked at the overall cost of the house it is small change. The positive is you start with at least R19+ as opposed to R13+ for 2X4. I have not built a 2X4 outside wall house here in VA in over 30 years, years ago many power companies will not hook up power to a new construction home framed with 2X4, Duke Power in NC was one of them when I built a house down there in the late 70s, it had to be 2X6 outside walls. It can get could out there in Denver. You will save energy both summer and winter. It is like someone telling you that a front wheel drive vehicle will go in the deep snow as good as a 4WD, no way.

I don't understand the fwd analogy. Who is telling someone something, and what is that something?

 

[PT Doc]

Look up 'advanced framing', here are some links to start...

http://www.buildingscience.com/documents/insights/bsi-030-advanced-framing

http://energy.gov/energysaver/articles/advanced-house-framing

http://www.greenbuildingadvisor.com/blogs/dept/musings/pros-and-cons-advanced-framing

I saw a video that a builder in Texas made about advanced framing. The comments were very funny. So many non believers.

There are some very energy efficient homes being built in Denver. Most homes have the ducts leak tested and a leak test through a simultated front door. Great numbers can be attained without going crazy with new fangled construction.

It's intersting to hear about the settling with blown insulation. The R value improves with blown compare to batt since everything in the bay is insulated as framing is never going to be truly 16" oc.

It was also interesting to read up on spray foam. Spray foaming the sill plates seems to give a good return based on the price and difficulty getting that insulated. At some point cost surely comes into the picture and the decision has to be made when to stop.

I appreciate the comments and look forward to hearing other points of view.

 

[boobag]

i build homes. and i calculated on a 2000 square foot ranch, that the material cost would add about 2,000. that includes lumber, drywall, insulation, and siding. how if the exterior were brick, there would be a lot more expense.
now, how much a builder will charge for it is another story.

 

[Jlbc212]

The only advantage (and it's a big advantage) in using 2x6 exterior wall framing is the added space for extra insulation. The energy savings over the expected life of the house are huge, hence the big advantage. In the long term framing with 2x6's and installing the extra insulation is much cheaper than framing with 2x4's.

 

[PT Doc]

i build homes. and i calculated on a 2000 square foot ranch, that the material cost would add about 2,000. that includes lumber, drywall, insulation, and siding. how if the exterior were brick, there would be a lot more expense.
now, how much a builder will charge for it is another story.

Can you explain the role of the exterior sheathing being siding or brick. I'm not sure how that would play a role since I envisioned the added 2" being taken from the inside of the structure.

Thanks for the calculation in your example. That is what I wanted to see.

 

[PT Doc]

The only advantage (and it's a big advantage) in using 2x6 exterior wall framing is the added space for extra insulation. The energy savings over the expected life of the house are huge, hence the big advantage. In the long term framing with 2x6's and installing the extra insulation is much cheaper than framing with 2x4's.

I very much agree. The cost of NG doubled based on the energy star sticker on my 2001 water heater compared to one that I replaced it with in 2011. Within reason, building a home with smart choices for efficiency make sense. It's a one time cost and energy costs will likely increase in the upcoming years.

 

[boobag]

Can you explain the role of the exterior sheathing being siding or brick. I'm not sure how that would play a role since I envisioned the added 2" being taken from the inside of the structure.

Thanks for the calculation in your example. That is what I wanted to see.

i was just calculating this on a house and my mind went off track, because i was also calculating the difference between 8' and 9' celings. so disregard my previous statement.

to go from 2x4 to 2x6 for the same house was around 750, but thats assuming the foundation and exterior dimensions stay the same. you'll lose square footage inside due to the walls being thicker.

 

[fury9]

The header will be the same just furred out with scrap 2x

 

[PT Doc]

I'm not sure if it is now code but I asked a builder about one model that had extensive 2x4 exterior wall framing and they said something to the effect that it was grandfathered in. So something has definitely changed and for the better.

 

[speed bump]

Unless you are doing spray foam or rigid foam or additional insulated sheathing 2x4 walls won't meet code in Colorado for insulation. 2x6 walls will be about 30% lower heat loss through your wall cavities and in general make for a stiffer house.

quick reference
https://energycode.pnl.gov/EnergyCodeReqs/?state=Colorado

 

[MScott]

Often, when upgrading from 2x4 construction to 2x6 the studs are placed on 24" centres rather than 16". Strength remains basically the same, but thermal bridging is reduced resulting in even greater insulation improvement. Also, the reduced number of studs means that the cost increase is less than the increased cost of lumber in most cases.

 

[Msliechty]

Just furr out the interior walls if you want to add more insulation If it's new construction is definitely go 2x 6 exterior walls and just **** up the added cost


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[PT Doc]

Thank you very much to everyone that chimed in. Such a wealth of information within the gj community. I am never surprised anymore with the info that can be gathered. Zeke, that means you too.

 

[Nowater]

You can make a quick estimate by dividing the perimeter of the structure (in feet) by 1.33feet to estimate about how many 2 x 4s are in the outside walls. Multiply that number by the cost difference in the studs.

Or just go with the 2 x 6s and get better insulation.