Hi all, new member here.

I live in the Central Florida area and am a bit "greener" than usual people around me. I've been interested in building a net-zero-energy home for some time, but at the same time want to protect my family from the harsh weather we experience here.

We're prone to both Hurricanes, Tornadoes and wildfires, and evacuations do occur every year or so.

I live in the land of home owners' associations and McMansions, so I'm not free to build any exotic looking house I want. But, I have quite a bit of freedom.

So, to summarize, I want a very energy efficient/insulating house but it should fit in with the neighborhood. This means Domes, for instance, are out even though I understand they are very strong during bad weather.

I've read that there are 2 ways to go for strength and energy conservation, the first being ICF (insulated concrete forms) and the other material called "CEB" (Compressed Earth Block).

After some searching, CEB seems to be a material used more in the southwest than the south east. I am not exactly clear if you can buy the CEB bricks, generally I only see the presses for sale to make your own and I have no idea if local soil will work in this application. Also, I am not clear if the house would have to look like an "adobe" style house that might stick out in the neighborhood.

Does anyone have experience with either of these materials? What are the pros/cons of each choice? Are CEBs even possible in Florida where it rains quite often? And would CEB be up to FL building codes?

I'd of course also have to find a builder knowlegable with the material as well locally so that is another concern.

The roofing seems more straightforward for energy conservation/sturdiness. Metal roofing with a high reflectivity.

Thanks for your suggestions in advance!

http://www.ecohomemagazine.com/news/2009/09/case-study-tornado-resistant-silo-home-debuts-in-greensburg-kan.aspx

Also Google Greenburg Kansas tornado, that is where the above home is.

http://inhabitat.com/greensburg-kansas-rebuilds-better-stronger-and-greener/

http://web.bsu.edu/capweb/portfolio/architecture/march/2008/Clemens_David.pdf

Beef you also have to consider average rainfall and humidity when considering building materials. In both regards FL is not that much different than here and we get almost daily afternoon rain during the summer. This means the question of will the CEB (or any material suitable for other locations) dry out and/or get destroyed by rain before you can finish building and stabilize them? Anything that relies on natural drying including mudding sheetrock, or painting (normal building) can be a challenge in the southeast.

Check this out.
http://www.youtube.com/watch?v=St4umWJttYk

Its in Pensacola, FL

oracle wrote:
Check this out.
http://www.youtube.com/watch?v=St4umWJttYk

Its in Pensacola, FL

This video is actually what got me interested in the first place! It seems like building technology has moved pretty far since this was made, specifically the ICF stuff. There is no question the dome shape is stronger, but it just doesn't have that traditional look I am comfortable with in most suburban american cities. You'd be labelled the "wierdo" of the neighborhood. The irony is not lost on me that you'd have the last laugh, though! But, at the same time, being unable to re-sell it and having difficulties furnishing it override the safety aspects, I guess.

Superadobe perhaps ?
http://calearth.org/building-designs/what-is-superadobe.html

I've been looking into this because I'm planning on headed to South Florida after graduation.

So far I think the Earthbag(superadobe) Homes are the most promising.

Cob may be viable if you have a decent amount of clay in your soil.

Beef wrote:
This video is actually what got me interested in the first place! It seems like building technology has moved pretty far since this was made, specifically the ICF stuff. There is no question the dome shape is stronger, but it just doesn't have that traditional look I am comfortable with in most suburban american cities. You'd be labelled the "wierdo" of the neighborhood. The irony is not lost on me that you'd have the last laugh, though! But, at the same time, being unable to re-sell it and having difficulties furnishing it override the safety aspects, I guess.

Yes, nobody wants to be the mushroom taster. We are held hostage to what someone else thinks is "lovely" but what we are drawn to is symmetry.

To me, a house that I can use as a storm shelter is beautiful. A house that needs a 4 ton unit instead of two five ton units is beautiful.

That said, an ICF is much better than stick. But you still have a roof. What ya gonna do there? An ICF house won't survive an F5 tornado. A concrete dome will.

earthbag dome

Beef wrote:
This video is actually what got me interested in the first place! It seems like building technology has moved pretty far since this was made, specifically the ICF stuff. There is no question the dome shape is stronger, but it just doesn't have that traditional look I am comfortable with in most suburban american cities. You'd be labelled the "wierdo" of the neighborhood. The irony is not lost on me that you'd have the last laugh, though! But, at the same time, being unable to re-sell it and having difficulties furnishing it override the safety aspects, I guess.

Id rather be a "weirdo" with a house, than a "normal" person without a house

You guys already have examples of the best structure for green building as well as being hurricane and tornado proof. The monolithic dome folks have a presence there and have already weathered a few hurricanes. If you are just looking for a shelter they have an option of building a monolithic dome that isn't insulated (called Eco-Shell).

http://www.monolithic.com/

Contact David South pertaining to this solution.

Hope this helps ......

Beef, what did you end up doing? I'm in the same situation. The previous house on site was wood and was literally eaten up by termites and mold/fungus, so I'm trying to avoid wood, but concrete is so energy-intensive. Also I'm on a small lot in the middle of a city so don't have the flexibility of someone on rural acreage. So far, code enforcement and permitting people love us for taking over the property and I don't want that to change, so I have to be very clear on what I'm doing.

I'm looking but not finding local (Florida) suppliers of something like compressed earth blocks.

Anyone help?

Compressed Earth Blocks - as far as I understand - are made on site from local soil, you don't buy them in. They are cheap on materials but expensive on time/labour.

For true storm proofing I'd look at earth berming of some sort - but this is more suitable fro rural areas where looks are less significant. You can also go some way to deflecting storm winds with earth banks to bounce the winds up and over the property. Call them raised planting beds/landscaping...

Personally, I would go with rammed earth over CEB. Much stronger because it is monolithic. CEB is just another form of masonry construction with the inherent weaknesses against shear forces that come with masonry.

You can use some Portland cement in the rammed earth mix to strengthen it some more, or perhaps a pozzolan or lime addition if Portland cement is unacceptable.

The shape of the building and how it presents to the heavy winds are really important elements to consider.

Unfortunately, there is no earth on my lit, only sand (plus the backyard is a septic field do can't be dug much), so something is going to have to be brought in, preferably from nearby.

I'm open to all practical suggestions. I'm thinking pressure-treated lumber would be greener than concrete. SIPs are a possibility, as long as they're not sandwiched with something toxic or termite-prone. I understand some are made from recycled foam, fwiw. Autoclaved concrete is somwhat local, but not much better than regular concrete.

* lot

Btw, I'm more concerned about heat, rain and humidity than hurricanes. It's almost like living under water.

And termites.

If toxicity is a concern, than please avoid pressure treated lumber. I really cannot imagine anyone calling pressure treated wood a green building material. Nasty stuff.
With a proper foundation and spaced off the ground appropriately, untreated wood that is protected from the elements will last for a very long time.

Thank you. I really haven't looked into what pressure-treated lumber is. It was suggested to me by a designer/drafter. After seeing what happened to the previous house on site within a space of a few years, using regular lumber is a scary prospect.

Andrea Wisner wrote:Thank you. I really haven't looked into what pressure-treated lumber is. It was suggested to me by a designer/drafter. After seeing what happened to the previous house on site within a space of a few years, using regular lumber is a scary prospect.

Treated lumber is a scarier prospect. With untreated and poor construction and maintenance you might have problems with the durability of your structure.
With treated lumber you can have real problems with your and your family's health.

Today's treatments don't appear to be as seriously toxic as some used in the past, but remember that the reason the wood is not consumed by termites, other insects or fungi is that it is toxic.

Termites need a protected path from the earth to the wood. A proper stem wall and some maintenance to keep the earth and the wood disconnected will stop termites.

Pressure treated timber is treated with toxins and is not 'green' or 'permie', and certainly not something we'd allow to be discussed on permies.com, especially in the natural building section.

Andrea Wisner wrote:Thank you. I really haven't looked into what pressure-treated lumber is. It was suggested to me by a designer/drafter. After seeing what happened
to the previous house on site within a space of a few years, using regular lumber is a scary prospect.

Andrea Wisner : Please look at this link below ! :

http://www.termiteweb.com/termite-mud-tubes/

Termites always leave a trail ! Termites can be excluded from your property ! Past mistakes do not have to be repeated! This includes using treated Wood !

You can have trees and shrubs close to the foundations of your house, foundations do NOT have to be pathways for Termites or carpenter ants to your home!

Any competent builder should know how to provide a safe secure home that excludes Termites and non-flying insect pests for just a few hundred dollars over

the costs of a non-protected home !

Most housing engineers would rather specify a house with treated foundations than trust that the contractor that the home-owner picks is competent to deliver
safe house ! This is simply the way it is, this isn't scare tactics on the part of the Building engineer, it is a matter of his natural desire to 'cover his/her Ass'

If your Building Engineer/ Architect is not willing to both provide adequate building plans, and back them up with on site supervision - you have the wrong 'Guy'

For the good of the Crafts ! Big AL

Hey, calm down everybody! I didn't realize that "pressure-treated" actually means "poison treated" and I definitely am not introducing any poison into my home. I hadn't researched it because I wasn't thinking much of wood for structure. There is no timber industry in Florida - the pitiful skinny pine trees here are probably not a great building material.

As to qualified builder, the builder is my husband (experienced carpenter, etc. etc.), the primary designer is me (permaculture certified, btw), and this is our first start-to-finish project. Actually not quite start-to-finish because the concrete slab is already there. So far my choice of structural material is autoclaved aerated concrete from 75 miles away or concrete fiber SIPs from almost 300 miles away (Miami). Note that these things use sand for a primary ingredient; sand is what Florida has. We could pour our own concrete mixture, but may have problems with permitting and it probably wouldn't be much greener, I've heard of concrete made with a high level of recycled plastic fiber (http://www.youris.com/Environment/Recycling/Plastic_Waste_Set_In_Concrete.kl), but I'm not finding any locally (FL). I'd love to just fill bottles or cartons with dirt, maybe combined with plastic fiber, but again, maybe permitting problems. Other building choices are regular concrete block or wood framing, with some kind of insulation added.

Aside from the structural walls and insulated unpainted galvalume roof (and rough plumbing, some electric, solar water heater unless we can get one used, cistern), everything else will be reclaimed or hand-made materials. We reclaimed what we could from the house we tore down, but other than the slab there wasn't much structural material to reclaim, being wood eaten by termites, mold, and other fungus - even the heavy, painted roof beams. The roof itself was made of some kind of cardboard with asphalt and rocks poured on top! My husband saved the rocks to put at the end of the driveway. We wouldn't want them near our plantings, being covered with asphalt (tar) as they were.

If anyone has any ideas for any type of building materials, please feel free to chime in.

This thread: http://www.permies.com/t/29551/natural-building/Geopolymers#345667 was helpful as it explains that MgO concrete does not use portland cement, and MgO is what the Miami SIP company provides.