We're planning to build a home here in Hawaii which will have neither heating nor air conditioning. Instead we will have a lot of open windows for ventilation. Is it still worth considering ICF? Or maybe a simpler question, would an ICF house with open windows stay cooler in moderately hot weather than a stick frame house with the same open windows? We will try to shade the walls with trees and other leafy things as much as possible. Aloha.

I can tell you in Tennessee in July I was outside of a large ICF home and went to the complete ICF basement that was not dried in and had no HVAC yet and it was still 20 degrees cooler. it was a considerable difference. home this helps.

Been in many icf basements with no windows, doors, or overhead doors. significant cooler than others i have been in.

i suspect much if not most of the heat load will come from the roof.
especially if it is a single story with a large footprint. its similar in s/e climate regions. but, if you dont have to worry about hurricanes or tornadoes, shading the openings will keep the warming sun rays out. keeping the roof material light colored and/or reflective, and good insulation in the roof structure will be the biggest help. icf walls are always nice for noise abatement and temperature fluctuations, but the roof is exposed to the sun all day.
insuldeckflorida

Agreed, roof systems are one big magnet for the suns rays.

Thanks for the help! We're planning a standing seam 'cool roof', to reflect as much heat as possible. I assume the noise abatement benefits of ICF fade rapidly once you open all the windows.

forgot to add the possibilty of termites....
there are icfs available with borates for protection, and most if not all are able to attach siding...
formed and poured concrete walls, vs stick-built, if a local concrete contractor is available, will address this problem...
then stucco or stone veneer, if you like the look....

The moderate to high R of ICF is overkill and not worth paying for in a Hawaii climate. Code-min for mass wall structures in HI are R3 continuous insulation if more than half the insulation is on the exteior, or R4 if mostly on the interior. The high solar angles make mid-day gains from walls almost non-existent- put the insulation money in the roof (a concrete roof makes sense), not the walls.

http://energycode.pnl.gov/EnergyCodeReqs/index.jsp?state=Hawaii

Mass walls are still a good choice in HI, but not necessarily ICF, especially since the mass effect is largely wasted when you have R8+ of foam isolating the interior from the concrete.

SCIP is a better choice for that climate, since the foam is on the interior where it's protected from termites by a full wrap shot-crete overcoat, and half the wall mass is in direct contact with the interior air. Putting most of the thermal mass in the floor is also a better use of the thermal mass of the concrete rather than the walls. Even an R10 SCIP would probably outperform an R20 ICF wall in that climate, due to the accessibility of the mass to the conditioned space.

https://www.facebook.com/TridipanelHawaii/photos_stream (<< never used these guys, found 'em in a google search)

Does this concept look familiar?:

http://www.concretedecor.net/decorativeconcretearticles/vol-11-no-3-april-2011/project-profile-hiilani-ecohouse-kukuihaele-hawaii/

http://www.hiilaniecohouse.com/scipconstr.html

http://www.islandplaster.com/hiilani-eco-house.html

http://www.sylvanecohouse.com/Tausch-Constr.html

Using stone slabs for the finish floor to add to the accessible thermal mass beyond the mere structural concrete can be useful too. These folks made good use of scrap 1-1/4" granite from a luxury countertop shop as a finish floor to enhance the thermal mass of their mostly-passive house:

http://www.greenbuildingadvisor.com/sites/default/files/Spartan%20-%20completed%20interior.jpg

TwoStepsBack,

I guess you already know that StrataUS has a Saebi Alternative Building System builder in HI.  Just like with ICF, get references and actually talk to people already living in SABS homes.