Hello. First off this site has been great for info. I have learned a tremendous ammount from the people here. Thanks.

Now, We are beining the process of desigining a home in Gulf Breeze Fl. It will be waterfront and needs to be eleveated. The design we came up with is about 2250 sq.ft. on a single living level, ICF, on pillings, with the underneath enclosed with garage doors. The basic shape is rectangular with no kick outs or nooks or anything like that. There would be one covered porch about 25 x 12. The porch could be wood and not part of the ICF structure. We would like the floor and roof to be ICF as well.

The question has anyone built anything similar to this design and if so what was the construction cost? I get alot of standard answers of 5% to 10%  more than wood frame but that's not helping me out much right now. I was hoping someone had done something close to this and could give me an idea of what they actually paid.

Thanks to all for any info you provide and also for all the things Ive learned here. C-

One more thing. Does anyone have the going average cost per sf of construction in the Gulf Breeze Fl. area?

Your best approach is to show your plans to local builders and get at least three quotes.  Even a simple home has a lot of variables that will affect the total cost.  The foundation can be significant.  What do builders use in that area for pilings?  How deep will the pilings be?  Are you shooting for the lowest initial cost or the lowest life cycle cost?  Since it will be ICF on pilings, I think you will need the services of a structural engineer to size the grade beam on top of the pilings.  A structural engineer may also be needed for the ICF portion.

You might want to also consider some mixes of rigid foam and poured or sprayed concrete. Ie, there are some combinations that would work just as well and yet not actually be ICFs.

Our cost for ICF walls, for 1600sq ft (x2) was about 30-33k. That's the icf blocks, rebar and concrete.

Posted By onesojourner on 12 Jul 2013 10:16 AM
Our cost for ICF walls, for 1600sq ft (x2) was about 30-33k. That's the icf blocks, rebar and concrete.

Is that 3,200 sqft of wall space for $33K? That would be around $10 per sqft of wall space.

Even a bottom of the line 2" + 2" R16 ICF is kinda overkill on wall-R for the climate in Gulf Breeze, though reinforced concrete has it's merits in hurricane zones if you tie in the roof well enough. A reinforced concrete wall with 2.5" of exterior-only EPS might even outperform it slightly from an energy use point of view, since it makes the full thermal mass of the concrete available for soaking up the other solar gains, whereas the R16 ICF isolates the thermal mass from the interior with R8.

It's a climate that's kind of dialed for SCIP construction, where the EPS is in the core, with concrete sprayed onto both sides, making the concrete the scratch coat for stucco on the exterior, hard plaster on the interior but I'm not sure how hard it is to find the right contractor in your area (could be harder than finding a competent ICF contractor.) With 3-4" of EPS in the core and 2" of heavy wire-reinforced concrete on both sides it's a very stout structure, and you can even make it a continuous monocoque with a SCIP-technlogy roof, which is VERY resilient against high wind forces and hurricane-blown 2x4s. It's less load for the pilings than an ICF wall too.

A lot of good info being given. The roof and floor can be InsulDeck and that can create a solid monolithic structure that would be hurricane resistant. Don't neglect the roof. Many people build concrete walls and then go with a wood truss roof, which almost always will fail in any high wind/rain event. Do it right and do it in concrete.

This might help out: ICF Florida

Thanks for the replys. We will be reght on the sound there which can get some nasty surge. On the maps we are in the "V" zone which means velocity. I imagine that the ICF would be the best although not the only choice. SIPS are the other thing I am looking at. Like all projects this will be a cost/value issue. I like the extra elevation that it seems I can get with concrete pilings. The house we designed is 1 living level on pilings with garage doors underneath on all sides to let water run through. The plan is 2250sf not including a deck, which could be timber.

Thanks for the ideas. Please keep them coming. C.

A couple of suggestions:

See http://gulfconcretechnology.com/  for Structural Concrete Insulated Panels (SCIP) from Long Beach, Mississippi. 

See http://www.pearsonpilings.com/  for fiberglass pilings.

I know someone with a raised house on the ocean in Florida. It works well, except that the car parked underneath gets ruined when a hurricane causes water levels to rise. I've wondered if he could build a completely water tight garage (think swimming pool with a watertight door).

Posted By jonr on 13 Jul 2013 04:13 PM
I know someone with a raised house on the ocean in Florida. It works well, except that the car parked underneath gets ruined when a hurricane causes water levels to rise. I've wondered if he could build a completely water tight garage (think swimming pool with a watertight door).

Or, he could take it out of the garage, wrap it in heavy duty plastic, tie a rope to it, and let it float! Seems like I read or heard of someone who did that!