I am getting closer to building my first house w/ the SABS system.  I thought I would share what I have learned so far about this system and related costs, etc.

Strata is expected to have a completed structural cost of around $25-$30 dollars per square foot.  This is an installed price, and would include structure, insulation, interior finish (i.e. no drywall necessary).  Approximate materials cost is around $7 linear foot.  This seems to be competitive with a rate for "custom" stick frame construction, but with increased R-value, air tight construction, etc.

Strata provides 2 methods of partnerships: $1200/year to be a licensed contractor - or - provide single-use support which includes engineering for $.50 square foot, plus the purchase of materials.  Materials can be sourced locally, and they have been experimenting with more efficient ways of distributing the ad-mixture necessary for the GFRC application.

I was interested in installing radiant floors, and discovered that the local EPS supplier can provide PEX routing in the styrofoam for the floor at the time of manufacture.  The process would be:  lay the PEX in the styrofoam, then shoot the GFRC on the flooring unit, creating a monolithic floor with PEX. Desired floor finish on top of the GFRC. This is intriguing to me, but have some question on how the heat would be distributed through the GFRC.

For significant dead load areas, an increased amount of GFRC is applied. 

They do recommend a waterproofing membrane on the roof on top of the GFRC due to the potential of hairline cracks in the GFRC. 

One potential difficulty is routing of the HVAC equipment.  Without too much detail, they said they had great success with creating soffits out of steel studs and drywall to distribute heat/cooling.  This would be a major consideration in the design aspects of a house. 

Your questions and feedback are appreciated.

A few questions.
1. Can you do basements with the SABS system?
2. Are you doing a basement on your house?
3. How was the HVAC installed in the first two SABS homes that are pictured on their website?
4. I noticed on the website that a lot of the technical documents are not completed yet, are these detailed engineering issues flushed out yet?
The SABS system appears to have a lot of advantages but until some of the details are flushed out its hard to evaluate it for a potential new build.

JW

Interesting, sure seems like good potential for a nice strong energy efficient home. Good luck! Where are you building?

So they are selling the engineering and the proprietary GFRC mix? Do they have a site manager for proper erection of foam panels and gfrc application? They give you the foam panel schedules for any local supplier to provide the material? Do they convert any home plan into their system or do they have architects/designers that can help that are familiar w/ the system?

Highperformancehomes (Matt)

Thank you for posting about the Strata system.  Please keep us informed about your progress and cost.  I saw this system at a trade show in Orlando a few years ago and have been trying to follow it ever since.

I may be wrong but I understood that a thin layer of concrete would be needed over the GFRC floor.  Money would be saved if tile, carpet, etc. could be applied directly over the GFRC without the topping concrete slab.

I also understand that this system could be used for a basement but Strata is concentrating on building above grade.

I am not an expert nor a spokesperson for this system, but here is what I can answer:

You can do basements, but requires additional engineering and a significantly larger amount of GFRC on the retaining portion of the wall. I don't think they have any experience doing a basement, and are therefore a little apprehensive at this early stage. I am planning on a walkout basement, and will probably use vertical ICF for the basement.

Not sure about how the hvac was installed on the houses shown, but both being in Arizona leads me to believe that there is no heating. The only information I have is that they were successful in building the soffits to accomodate any hvac equipment. At one point they were using I beams for the floor, and I would think this would lend an opportunity to route mechanicals through, but not sure at this point.

Alot of technical documents are available, and the ICC-ES report is the most revealing and technical. They are 98% complete with a new construction manual, and that will be helpful. They readily admit that all of the kinks are not worked out yet, and are constantly finding revisions to the current process. Most of the changes appear to be in the process of construction and distribution, and not related to the physical components

Essentially they are selling the FEA analysis and GFRC mix. From what I understand, they will provide a site manager for the spraying portion of the process. They will take an existing floorplan and make suggestions and/or changes as needed. I was told I need to submit the plan and they will quickly look at it and return to me a fee schedule, depending on the complexity and completeness of the original floor plan.

Alton - you can call me Matt

You are right about the floor. You would have to finish the floor as you would the rest of the structure.

Very interested in your build. Thanks for contributing here, and please take a million pictures as the process evolves. A couple questions come to mind:
1. How do you hang cabinets? Embedded lumber? Or is the half-inch layer of GFRC strong enough alone?
2. If building on a slab, does one forego the EPS floor component? If so, how is the structure anchored to the slab?
3. If the roof will need some type of additional covering anyway, can traditional roofing materials be used (I am thinking the Ondura roof system would complement the 'stucco' finish nicely)?

Thanks again, and good luck!

MountainStone,

I am very interested in this system and hope to use it someday in one of my projects.

From talking with the SABS company at a trade show in Orlando a few years ago I was told the following:

The 1/4" thick GFRC coating is strong enough to hold cabinets without embedding wood.  The GFRC has to be pre-drilled to accept a certain type of screw. 

The walls are anchored directly to the footer with 3/4" thick radius of GFRC on both sides and then the floor slab is placed up against the wall.

The roof does require some type of roofing material in addition to the GFRC.

My information may be out of date by now.  Maybe someone on this forum using this system can  provide current info.

one of the questions that I have about this system is can the EPS for the walls be precut and conduit/wire chases pre-installed similar to what is done with SIPS. This would minimize the cutting of the EPS that would have to be done on site. Perhaps electrical boxes could be pre-installed as well. I don't know if there would be some issues with the way that the EPS blocks are glued that would prevent this from being done. Also if your design did not call for vaulted ceilings how would you handle the
HVAC.
JW

Alton,

So the slab is poured to a level ABOVE the footer on the interior to anchor the walls? Clever. In regards to installing a roofing system, I wonder how traditional materials are utilized considering that fastening into the GFRC must be accomplished by drilling and anchoring. That's good news about the cabinets, though.

jperiod,

Your ideas about employing more sophisticated manufacturing to the EPS blocks reveals a potential business opportunity. A company could design and engineer floorplans, manufacture huge EPS panels with all chases, conduits, ducting, etc and deliver to the jobsite via tractor-trailer. A small crew could assemble the large but lightweight EPS panels into the shell in one day and shoot the GFRC the next day.

When I was stationed in Saudi Arabia, I had the opportunity to drive around and view the 'suburbs.' All the houses there were constructed of formed/poured concrete. The structures could be quite elaborate and beautiful. They tend toward walled compounds with fanciful balconies, balustrades, crenelations and sophisticated architectural details. Methinks such beautiful details could easily and inexpensively be constructed with the SABS system, provided with sculpted EPS blocks.

I am not sure, but it seems possible to have all of the routing precut at the EPS factory. You would have to spend additional time in the design phase to include all of this in your CAD drawing, but that is probably a good thing anyways.

Handling the HVAC would be handled with either custom soffits or crawlspace in a one-story house. This is one area that I am not 100% confident with yet. Its essential to have a good architect that can work (read willing to work)with this new system.