Forums > Specific Focus > Home, Garden & Construction in Mexico

gustavo

Mar 31, 2005, 8:01 PM

Post #1 of 17 (5607 views)

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Sustainable building?

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I Just inherited a small lot in Guayabitos (10m x 30m, nr P Vallarta) and will be going down there to check it out. I've been doing some preliminary research on Sustainable Design techniques and am curious to hear your opinions of what might work for this area in terms of practicality (performance, availability & cost). I am a complete building novice and the project is still a ways off, but any upfront advice would be welcome. Thinking about a modest 2-3 bdrm home, maybe 1000ft2 footprint.

Techniques I am considering: Adobe, Strawbale, Cob, Earthships, Rammed earth. Passive cooling

Cost/Availability of materials and architects with expertise?

Thatched roof vs tile?

Solar Panel cost/availability?

Water catchment and Greywater systems?

THANKS!

jreboll

Apr 2, 2005, 5:40 AM

Post #2 of 17 (5569 views)

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Re: [gustavo] Sustainable building?

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Some of the techniques you mentioned use very thick walls. That might use up some of your living space.

abq

Apr 2, 2005, 9:08 AM

Post #3 of 17 (5551 views)

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Re: [gustavo] Sustainable building?

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I'm no expert but I've heard adobe doesn't fare well in humid climates. Do you get hurricanes there? That might be a factor in your decision.

Adobe is thicker and will eat up some of your living space.. Especially if used in both exterior and interior walls.

patricio_lintz

Apr 2, 2005, 11:53 AM

Post #4 of 17 (5540 views)

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Re: [gustavo] Sustainable building?

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Many of these topics have been discussed previously. If you search the forums for key words, there may be discussions which would help.

gustavo

Apr 4, 2005, 8:24 PM

Post #5 of 17 (5499 views)

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Re: [patricio_lintz] Sustainable building?

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Thanks, I've been doing some searches on the forum and have found a little info, but not exactly what i need. I'm hoping for references of green architects or design/build companies... I have found some refernces of strawbale buildings around Morelia and Tepotzlan but none on the coast so far.

I just had a one day seminar on Strawbale and Cob yesterday and asked some basic questions about building in sub-tropic mexico climate. The Strawbale and Cob guy basically said YES it is possible and viable as long as the HUMIDITY doesnt stay above 80% for extended periods (months). I noticed todays humidity in P Vallarta was 58%, much higher in the summer, so i'll have to keep my eye on this.

The interior/exterior of both of these are lime-plastered which keeps the water out of the walls. One must design it properly to keep water contact at a minimum by making large enough overhangs and built on a cement foundation to keep the base of the strawbale/cob from sitting on water. There are many cob buildings in England which are about 400-500 yrs old withstanding lots of rain there...

Yes, the walls are thick (2ft) but if designed/built correctly the comfort level with low energy needs makes it very attractive. You can build large windows into them for max daylighting. I personally love the organic aesthetic and natural qualities, using local, cheap low embodied-energy materials. We'll see what happens. I'm sure i'll be back for more questions...

abq

Apr 5, 2005, 6:07 AM

Post #6 of 17 (5488 views)

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Re: [gustavo] Sustainable building?

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Have you considered a nice palapa building? Pretty sustainable matiarials. In that area you don"t need insulation. You do deed to catch the breezes as much as you can.

gustavo

Apr 5, 2005, 1:34 PM

Post #7 of 17 (5465 views)

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Re: [abq] Sustainable building?

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YES, definitely thinking palapas! i love the look of these palma roofs and know they are local and sustainable. i was thinking of combining this with another technique or two. i like to push the envelope in whatever i'm doing and promote alternative concepts (if they make sense of course). I think mexico is ripe for sustainable building solutions amidst all the gringo invasive development...

i know airflow design is key for cooling. the insulation concern is for keeping cool when the breezes are warm during hot summer months, no way i want to put AC.

still a ways to go before i decide on anything, and longer til i put a shovel in the ground...

Esteban

Apr 5, 2005, 2:02 PM

Post #8 of 17 (5460 views)

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Re: [gustavo] Sustainable building?

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Palapa roofs are full of bugs right? Not bad for a restaurant or for someone who can't afford anything else. As to AC, it takes being born in the swamp to not want AC in the summer months in the coastal cities. Im always looking for something alternative too and would love to give up my $100 a month elec bill in the summer. Please, if you have a idea for cooling without AC let me know. I live across the street from homes on the water. The ones on the water get the breezes and don't require turning on the AC at least a month at either end of the summer heat compared to our location. I'd suggest buying on a hill, and discovering the breezy sites and build accordingly but I find it highly unlikely you'll not want AC unless maybe you're from Louisiana.

gustavo

Apr 5, 2005, 2:58 PM

Post #9 of 17 (5452 views)

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Re: [Esteban] Sustainable building?

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as a kid i went to mexico for the whole summer sevral times and always thought the heat and mosquitos were so oppressive, which is why i'm going in may (delayed from march) .

The property i have is on a gentle sloping hill with an oceanview about 1-2km from beach but no idea what airflow is like. the keys to keeping a home cool is DESIGN: strategic SHADE using building orientation, trees and adequate window overhangs. Low vents for incoming air which circulate around the house and escape thru a High ceiling vent, and insulative materials with high thermal mass such as adobe or strawbale. If you can keep the floor cool then your body will feel coooler than the actual air temp.

From what i've read and been told, utility bills for a well-designed passive heating/cooling strawbale home are 5-10% of what a normal woodframe home uses. yup, 5%! no suffering necessary...The main limitation for strawbale would be that it shouldnt be above 80% humidity many months in a row, so it may not work out down there, not sure, still doing research on that.

do you knwo what humidity % during these months? 90-100 ?

Esteban

Apr 5, 2005, 3:08 PM

Post #10 of 17 (5450 views)

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Re: [gustavo] Sustainable building?

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with an ocean view and that close to the beach, you should get a good bit of drier wind. Even with your distance from the ocean it should be drier, however, I don't know for sure. In Mazatlan (its not as humid as south of here) it's easily 80% humidity for around 4 to 6 months of the year. I like your passive cooling ideas but I'd be thinking in terms of concrete and tile rather than straw bale or wood. Using reflective surfaces, high ceilings, fans, proper venting, overhangs etc....all sound like they could work. But, you'll still be wanting an AC unit in at least the bedroom. That way you can SLEEP at night. Keep the bedrooom small because we all know cooling is about CUBIC FEET. Or, at least keep one or two bedrooms small with an AC because you probably wont have a lot of guests during the hot summer months and you can move into one of them until the winter months come back.

abq

Apr 6, 2005, 8:35 AM

Post #11 of 17 (5424 views)

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Re: [gustavo] Sustainable building?

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You're giving the gringos way too much credit. Development on the coast (invasive or not) would go on with or without the gringos. Mexicans are not all poor and many own second houses on the beach.

All that insulation in such a humid climate sounds like a mold trap to me. And you'd only save energy if you are using refrigerated air, The wind is free.

I really admired the Colonial homes I saw in Granada. The first floors were really porches, all open to the central courtyard. The second floor bedrooms were closed off more and if the residents could afford it were airconditioned. That design would be a challange on such a small lot but the design elements could be incorperated.

patricio_lintz

Apr 6, 2005, 10:23 AM

Post #12 of 17 (5417 views)

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Re: [gustavo] Sustainable building?

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http://maztravel.com/maz/climate.html

look at monthly humidity here.

My own advice is that sustainable building is a romantic idea. I went through all of the same tradeoffs. However, Mexicans have been building with masonary since times of the Mayas.

Bricks, mortar and labor are cheap, plus you help sustain people who really need the work. Mexico is an industrialized country, people here are used to masonary. They would have no idea how to use some of the other techniques.

That being said, I went with all styrofoam panel construction. When coated with two inches of cement inside and outside, the result is a self-insulating monolithic shell. Hurricane and earthquake resistant. Not that I have any concern of hurricanes on Lake Chapala.

I have no heating or cooling installed. Put on an extra blanket if it freezes!

The local albaniles here have built some of these. They work out well here. Technology is not all bad. Especially if you trade it off vs mildew, maintenance, insects, etc.

Palapas have to be re-roofed every several years. Any moderate blow will unroof them. As Kermit said, " It's not easy being green!" More importantly: Can you afford to be green?

wyhaines

Apr 7, 2005, 8:53 AM

Post #13 of 17 (5380 views)

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Re: [gustavo] Sustainable building?

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Strawbale has been very successfully used in the more arid regions of Mexico, and has been used successfully in some humid regions of the US.

Do not depend on your lime plaster to keep water off of your walls, however.

If it were me, I would build with ample overhangs, probably extending the overhangs sufficiently to form a wraparound porch around your house. I would use an earthen plaster on the exterior of the bales, and would cover that with a ventilated rainscreen.

I'd build two or three small, inexpensive structures, and use the porches to extend the living space, around them. The climate is very amenable to this, and especially if you are doing some or all of the work yourself, you should be able to build in this way very inexpensively.

Take a look here http://strawbale.archinet.com.au/ for some examples of this general philosophy of construction.

I would also probably start with a single small structure, if your situation allows for it. Something big enough to be useful, but small enough that if the humidity does appear to be a problem, a building failure will not be expensive. Embed some moisture probes into the walls of the structure, and monitor it periodically for a year. At the end of that year drill out some samples and see how everything is doing. If adequately protected from liquid water, and if an earthen plaster is used, I imagine it'll be fine, but this would be the best way to prove that without risking a lot of $$$.

Athen and Bill Steen (http://www.caneloproject.com) have a lot of experience building with straw in Mexico, but their work has all taken place in the arid northern areas. Still, their web site and their writings are a great source of information on the topic.

Kirk Haines

toocrazy

May 5, 2005, 2:37 PM

Post #14 of 17 (5322 views)

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Re: [Esteban] Sustainable building?

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There are some very good points about being green from others when designing your home. The point about the small lot is valid and will be a challenge in the design but here is a site you may want to look at and explore the idea of a wind cool tower. http://www.i4at.org/lib2/aircool.htm
As Esteban said, I don’t think I’ll want to be without AC in the summer months but this may help as a supplement.

latitude26

May 8, 2005, 12:42 PM

Post #15 of 17 (5264 views)

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Re: [toocrazy] Sustainable building?

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In our location in Baja Sur we have no choice but solar power and what we have learned is that it costs alot of green to be "green". To get the highest quality equipment we bring down (import) all of the panels,batteries etc and luckily we're able to drive down from the US.
If you go the solar route, plan way ahead to get your equipment- dealers have trouble getting the good quality panels from manufacturers because the "good stuff" all goes to Europe nowadays where the demand is greater. You will mostly likely have to get on a waiting list to get your panels depending what you choose.

A combo system seems like it would be ideal if you have access to town electricity-keep some batteries charged by the town power for emergencies, run your AC off of AC, and use your panels for lights,water pumping etc.

If you itemize your expected daily power needs and set your system up to meet those needs, remember that each time you want to add an appliance (no matter how small) you may have to add another panel and battery to your setup. This can add another $400-600 dollars to each little thing you want to put in your house.

wyhaines

May 9, 2005, 6:02 AM

Post #16 of 17 (5238 views)

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Re: [latitude26] Sustainable building?

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What about wind? I would think the Pacific coast would be a good location, in general, for wind power generation. I know it is farther north up the coast. Southwest Windpower makes some amazing little turbines that work well in a modular, pay-as-you-go system. http://www.windenergy.com is their URL. If one has sufficient available wind, combining solar generation with wind generation makes a lot of sense to me, as they often tend to complement eachother. The days with the most sun are often the calmest, and the days with the least sun are often the windiest.

Kirk Haines

latitude26

May 17, 2005, 1:35 PM

Post #17 of 17 (5164 views)

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Re: [wyhaines] Sustainable building?

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Our property is just outside the remote town of SAn Juanico in BCS (pop. about 500). In 1999 the town was the beneficiary of a "Hybrid" solar and wind power generating system. This was a joint venture between several entities and was researched and co-ordinated by the Sandia National Lab which is a division of the US dept . of energy.

Sandia monitored the wind 24/7 for one year to determine the feasibility of wind turbine power prior to installing the large turbines (10 of them). We contacted them and explained that we were evaluating wind versus solar power for a home in San Juanico and they generously shared the wind data they had collected.

We were surprised that although we always thought of it as a windy place, the average sustained daily wind was not all that much. I don't remember the exact figures with regards to number of hours per day of what m.p.h. of wind and the number of watt/hours we could expect, but we figured out that that solar panels were less expensive for the amount of watts we would be getting daily and year round.

The American companies and agencies handed over the operation of the power system to the locals and it has fallen in to some disrepair. When the town got "power" for the first time folks went out and bought refers, tv, washers and electrical things they had never had before. This of course changed the estimations of the town's power needs that had done prior to setting up the system. So the towns old diesel generator still runs about the same number of hours per day that it used to!

We asked a guy at Sandia why the power systems were set up in Mexico and not some where in the US. He replied that the laws and red tape of setting up and studying such a system in the US made it cost prohibitive for them to do research.