NOTE: Make sure you read the first three posts (in order!) before tackling the rest, or it could be confusing: Post 1 is Designing the future, Post 2 is Setting up the problem, and Post 3 is Estimating basic requirements.

 Web peakoildesign.blogspot.com

Friday, October 27, 2006

Why not blow away Peak Oil?

RobTzu called me in to an interesting thread on LATOC discussing challenges to the notion that we can't save the world from energy decline after Peak Oil. In the thread, we calculated the required cost to replace the current world power usage fully with wind energy. Here was my contribution:

Well, my good calculator went missing at work a few months back, but I'll give it a try anyway :)

Actually, I get slightly different numbers, but your methods are essentially sound:

387.21*10^15 BTU = 4.09*10^20 J = 4.09*10^17 kJ
(reference #4 has an error: it cites 1054 for BTU -> kJ when it should be 1055 for BTU -> J)

For world power consumption for one year:
4.09*10^17 kJ /[(365.25 d)*(24 h/d)*(3600 s/h)] = 1.3*10^10 kW
(I'm not sure what number you used for the total time in the denominator -- perhaps I've made an incorrect assumption here on what you wanted to calculate)

Number of solar arrays = (1.3*10^10 kW)/(20 kW) = 6.5*10^8

Cost = (6.5*10^8)*\$6000 = \$3.9*10^12 (\$3.9 Trillion)
However, I see a problem with using reference 2 for the price: it says that units from 2 kW to 20 kW start at \$6000 -- so I think the lower number is for the 2 kW unit. We can either find a different source or use the 2 kW for \$6000 (still low, I think), which gives us:
Cost = \$39 Trillion

One more factor we're missing: In the first line of your post, Rob, it says that wind turbine power is really half the equivalent coal power effectiveness over the course of a year. So, multiply by 2:
Cost = \$78 Trillion

Although this is significantly smaller than the numbers you calculated, the main point is still the same: It is incredibly difficult and expensive to replace the entire world electrical grid with wind energy. Even though the number I calculated is near world GDP, it would take at least a decade to scale up production to produce the required number of wind generators. This is if we commit all our economic resources to the project, including food (as Rob pointed out). And, this still doesn't account for what is required to meet current growth in demand.

Solutions for saving the entire world from living with reduced energy is not possible, even with massive conservation, and even if we develop commercial fusion tomorrow. That said, we can save a lot of people from hardship by a massive redirection of efforts if we start now. However, this won't happen anytime soon -- and the longer we wait, the less we can achive. For now, we need to focus on who each of us can protect with our given resources, and design accordingly.

Wednesday, October 25, 2006

Trained farm dogs were essential in the past and will be so again in the future. Dogs help with herding livestock, fighting off predators, warning against intruders, and (of course) entertaining the children.

Our dog is a Catahoula (at least in part), although we didn’t know that when we got him from the animal shelter in Florida. Catahoulas are dogs typically trained for herding cattle and wrangling wild boar, and make fabulous hunting and guard dogs. We need to learn how to train him for these sort of activities eventually, but for now our main problem is trying to get him enough exercise with on our small suburban lot – they typically need 1 hour of free running time every day! And when he tries going over the fence at every squirrel and small dog, it’s tough to keep him contained. :)

So, my message today is to look into what sort of critters might help you out in your post-Peak Oil future, and make sure to include in your plans how you can best ensure you can keep them healthy and well-fed when the pet food factories disappear…

Monday, October 23, 2006

Water Requirements Throwdown

Once you’ve reasonably developed the high-level requirements for your design, it’s time to whip out as many requirements as you can. As one of the major concerns following Peak Oil is adequate water supplies, we can start by focusing on water requirements. We’ll also explore a few examples of effective requirements writing.

The water system shall provide potable tap water at a temperature suitable for drinking.

This requirement has the right idea, but how do we define what temperature is suitable for drinking? We could say it will provide “cool” water, but there’s no solid definition for this. According to the Association of Home Appliance Manufacturers cold tap water (for appliance purposes) is less than 86 ° F. There aren’t many solid references on “comfortable” cold tap water, so for now let’s choose (by intuition) 50 ° F for the lower end of cold tap water temperature range.

Similarly, we need a requirement for hot tap water. We can use guidance from the reference above:
The water system shall provide potable tap water at 112 ° F – 145 ° F.

Since one of our driving objectives is that the homestead will be safe for children, we need to ensure that the hot tap water isn’t too hot. However, there is a risk of Legionnaire’s Disease if they are allowed to incubate in hot water.
So we need a balance between water that reduces the risk of Legionnaire’s Disease yet doesn’t scald children. You can weight the competing concerns yourself, but remember that you don’t have to have a hot water heater – you could use a tankless heater or go old fashioned and boil water on the stove yourself. So there are design solutions that could meet the competing requirements.

With an eye toward maintainability, we can write:
The water system shall provide a source shut-off mechanism.
This function will enable practical servicing of the water system.

The water system shall remain above 40 ° F at all points.
This is to ensure the pipes won’t freeze in winter. It’s unlikely you would need a similar requirement on the high end – but worth considering if there’s a chance you could approach boiling (maybe a design-specific requirement when the time comes).

Thursday, October 19, 2006

Peak Oil dividing lines

The Peak Oil community is divided into three main camps: “doomers”, who anticipate devastating and total collapse; “optimists”, who believe technological breakthroughs will mitigate most of the crisis; and “cornucopians”, who believe any potential peak is decades or centuries away (or non-existent altogether).

Personally, I would fall somewhere between doomer and optimist. After analyzing production and usage data for energy, getting a good grasp of the physics of energy usage, and obtaining a limited education in the world’s complex economics, I’ve concluded that a major energy and economic collapse is inevitable in our near future. (This is even with excluding the converging crises of water, global warming, and pollution from the discussion.) I have no confidence that an energy alternative capable of approaching our increasing demand will magically appear.

A community may not have enough foresight, labour, tools, or funds to create alternatives to whatever their members use now for heating, lighting, cooking, refrigeration, water collection, water pumping, and disposal utilization of gray water and human waste.

There may be pockets of survivors who will be able to harness wind, water and sun using civilized technology for a while, but eventually the machines will wear out.
Where do you buy replacement parts, how do you make parts without plastic or wires?
How do you refine the metals needed to make circuits and transistors?
Those who know, no longer do; those who do, no longer know. How much knowledge will manage to survive the post collapse period, for the time that comes after when it may become useful again?

The author paints a dreary doomerish prospect for the future, but for me it reinforces my belief in careful engineering design. I have no illusions that life for isolated communities will be difficult. I do have faith, however, that we will have the capacity to engineer novel methods to capture solar, wind, and water energy, if not sustain our existing equipment. Yes, manufacturing wires and silicon panels is difficult without an industrial infrastructure, but I believe we can find alternative (if less efficient) processes to do so.

Such is my faith in the power of technology – innovation won’t allow us to live beyond our available energy, but it will enable us to find sustainable solutions to continue a reasonably energized life.

Wednesday, October 18, 2006

The link to the Objectives and Requirements Document for the Peak Oil Homestead Example Problem on the right sidebar now links to an updated document. The free site I'm temporarily using doesn't allow hot-linking, so there's an intermediate click required. This is just a temporary fix until I get a new site up and running.

Requirements Management

Lately I’ve been focusing a lot on sustainable Peak Oil solutions, but we need to make sure we don’t lose site of the design process. In the spirit of keeping organized (which is about 85% of Systems Engineering), I’d like to direct your attention again to our development of the Homestead Problem. The Objectives and Requirements Document (ORD) for the Homestead Problem is linked at the top of the right sidebar.

We’ve slowly developed a number of requirements over the past few months, and now you can see where they fit within the hierarchy.

There are some key ideas in requirements management:

1) No orphans -- Each requirement needs to link back to either a higher-level one or an objective
2) Hierarchy – All requirements at a given level must describe the same system. The size requirements of your rainwater cistern (if you have one) belong at a lower level than your basic water requirements.
3) Baselining – Each level in the hierarchy should be frozen against further modification before advancing too far. This prevents you from constantly reworking all of your requirements and helps force you to ensure the “goodness” of the higher-level requirements. The common rule of thumb is that you can work up or down one level from your current one, but the higher levels must be frozen before continuing. (Example: Requirement 2.1.1 for 280 lpd of potable water is the highest-level; the next could be regarding the water system temperature; the next level requirement would be regarding a specific component of the system (say the cistern). In this example we can’t move on to the third level until we baseline Requirement 2.1.1)
This doesn’t mean you can never change the higher-level requirements, it just gets harder as your design matures.

As always, strive to keep specific design solutions out of your requirements. It can be difficult not to design, but try to focus on defining your needs before figuring out how to meet them. You design will be so much better if you resist the temptation.

Tuesday, October 17, 2006

Info on NETL or Morgantown, WV

I may have the opportunity to transfer to a job with the Department of Energy’s National Energy Technology Laboratory (NETL) in Morgantown, WV. I was wondering if anyone here could tell me about either the laboratory or the surrounding area. As our next move will likely be our last, I’m particularly interested in the sustainability aspects: soil, climate, community, and other resources. I think the job would be fabulous -- working on potential Peak Oil solutions (hopefully). Thanks to anyone who can help.

Peak Oil Summary & Solutions

The absolute best Peak Oil article I’ve read so far was on Energy Bulletin yesterday. It sums up nearly every aspect of the crisis from a calm, rational perspective and presents the facts plainly.

From the article:

"From our perspective peak oil is not a tragedy, as long as it's handled correctly." As oil depletes and countries like China and India start to compete against the U.S. and Europe for increasingly limited supplies, Murphy sees a danger of more oil wars like Iraq.

"We are no longer attracted by the siren singers of breakthrough technologies that promise us we can continue living in a manner that denies a future for our children," Murphy told conference participants. "The solutions are not going to come from the same people who created the problem. The answers are not in the corporations of technology but in the villages and neighborhoods."

"There's this need to change our oil use driven by the supply question and from another direction by the global-warming question," Murphy said. "That's been causing a lot of cognitive dissonance. It took me about six months to understand that the issue is not how long the other half of the oil will last but that we can't burn the other half of the oil."

Monday, October 16, 2006

Breaking down energy needs: Insulation (Part 2)

In the last post we discussed the common industry insulation measure known as the R-value. Focusing solely on a material’s R-value can be a major mistake, however.

First, R-values are determined under very specific laboratory conditions: in a warm, dry, wind-free environment. Of course, every home is subject to wind and precipitation, and even protected layers of insulation will be affected by weather. Fiberglass insulation loses nearly all of its thermal properties when wet, and allows air to flow through it easily even when dry.

In order to properly insulate your house, you need to seal your home against moisture and wind. Some go so far as to recommend against fiber insulation altogether.

Vapor barriers should be placed on the warmest side of the insulation. This is obvious in either very hot or very cold climates, but in places where the temperature varies wildly throughout the year the placement isn’t always readily apparent. No matter what the case, you should never put moisture barriers on both sides of the insulation – that will prevent the moisture that forms (and it always will to some degree) from escaping. Trapped moisture can both ruin insulation and lead to mold growth.

Solid insulation has a lot of benefits over fiber insulation. In general, it prevents airflow and is more resistant to moisture. Spray-on insulation (such as polyurethane) is better than pre-formed sheets as it allows a complete seal, but petroleum-based insulation introduces several Peak Oil/environmental concerns. Someday your insulation will need replacement, and the old waste insulation will need to go somewhere. In addition, such materials won’t be available post-Peak Oil, and if you didn’t make accommodations for natural insulation you might lose valuable home thermal properties you counted on in your initial design.

Properly sealing your home is critical. This includes horizontal sealing between studs; sealing around outlets, windows, and doors; and sealing between the walls and vertical connections. Eliminate air gaps at all points (such as at the top of walls), as air has a much smaller R-value than insulation.

So great, your home is now fully insulated and sealed all around with an R-value of 70…and now you can’t breathe because you have no air exchange. You need ventilation, and that will be the focus of a future post.

References:
Monolithic Dome Institute
U.S. Department of Energy
Kansas State University
Ecobuild Network

Sunday, October 15, 2006

Conservation tips

I recently came across a great website called Blue Girl, Red State with some excellent perspective on sustainability and environmental issues. They recently posted a collection of conservation tips I thought I'd share here.

An excerpt from the post:

If everyone would run their electronics through a zip-strip and flip that switch off when the electronics are not in use, it would save a tremendous amount of energy, at both the micro and macro levels. While we are making modest adjustments that are capable of having a huge impact: Never purchase another incandescent lightbulb for as long as you live. Buy the flourescent bulbs that are all the rage. They aren't a fad - I've been using them since the early 90's, when they first came out and cost through the nose. Now my light company is paying a rebate on the purchase of them in the form of credit on your monthly bill. Total cost after KCP&L subsidizes the purchase: \$.99 - and you will save that much in three months time in saved energy consumed by each bulb. When you buy a new TV, get an LCD; skip the power-suckin' Plasmas and CRTs.

Friday, October 13, 2006

Breaking down energy needs: Insulation (Part 1)

An often-mentioned number in home building is “R-value” or “R factor”. The R-value is a measure of a material’s resistance to heat transfer and is used to compare different types of insulation. It is calculated using the thermal conductivity constant, k:

R = [thickness (in inches)] / k
k = [BTU * inch]/[ft^2 * hours * ˚F]

Insulation must be treated as a whole-structure concept. Just as the amount of insulation in your home means little if you leave your door wide open, using very high-R material in the walls may provide little return if you use low-R windows. It’s all in the rate of heat transfer.

The following table provides some common measurements for R-values compiled from various sources. A few things to note: R-values are calculated under ideal laboratory conditions and may vary considerably “in the field” (more on this later); these R-values are valid for wall, roof, or floor calculations; R-values for green roofs can be complicated and will also be discussed later.

MaterialR-value per inch thicknessR-value per unit
Metal0.0
Concrete0.08
Gypsum0.6 – 0.9
Hardwood (oak, maple)0.91 - 0.94
Softwood (fir, pine)1.3
Plywood1.25
Fiberglass3.0 – 3.8
Strawbale1.45
Sand/gravel0.6
Stucco0.2
Brick0.1 – 0.2
Asphalt shingles0.44
Aluminum/Steel Siding 0.61/panel
Loose cellulose2.8 – 3.7
Loose fiberglass2.2 – 4.0
Loose rock wool3.1
Loose vermiculite2.2
Molded polystyrene3.6
Extruded polystyrene3.6
Polyurethane foam5.6 – 6.2
Sprayed cellulose3.0 – 4.0
Carpet (with padding) 1.2 – 2.1/layer
Air (3/4” – 4”) 0.9
Windows
- Single 0.76 – 1.1/unit
- Double 1.2 – 2.2/unit
- Triple 1.3 – 2.6/unit
- Double, low emissivity 1.3 – 2.9/unit
Cement mortar0.2
Vinyl 0.05/layer
Soil (fine, 20% moist)0.08

Coming up next: The Fallacy of R-value Tunnel Vision

References:
Roofhelp.com
Oswego University
Grassroots

Thursday, October 12, 2006

Developing Peak Oil Skills: Get organized

Most people who have studied Peak Oil for even a short while recognize that certain skills are required in order to survive in an energy-deprived future. You have probably started collecting a short list of things to do or learn as soon as possible or perhaps just formed a vague vision of your future life.
Part of designing a sustainable home or community is designing our skill set. Each of us needs to develop requirements for ourselves based on our predicted needs and our existing skill sets. There are good lists like this one at Simple Living, and many such resources at LATOC, but each person will be different in their needs. Also, for this exercise I would emphasize skill acquisition over “activities”. Getting out of debt, moving to the country, making friends, and so forth are extremely important but belong on a different list than what I’m focused on here. A separate skills list will help keep you organized and focused on self-sustainability. You could set aside time every day or week to focus on skills development, working from your list.
I plan to run a continuous series within this blog highlighting my own learning process as I use Systems Engineering to design my future self. I’ll share what I’ve learned in hopes of easing the learning process for all who are interested. Remember that you cannot acquire a skill without actually doing it (repeatedly) and that your self-requirements list will likely be very different from my own.

My list of skills to acquire:
1) Food preservation: Canning, smoking, drying, freezing, etc.
2) Cheesemaking
3) Sustainable gardening
4) Building techniques: Foundations, framing, roofing, plumbing, wiring, carpentry
5) Blacksmithing/metalworking
6) Animal husbandry: Chickens, cows, sheep, alpaca; milking, butchering, shearing
7) Papermaking: Toilet paper, writing paper, wrapping
8) Hunting: Firearms, archery, trapping

Please remember a few things about this list: This does not include skills that I already possess; my list should complement my wife’s list so that we have an even distribution of required skills; and this list is dynamic – as I gain proficiency at some things I’ll be able to add more (less critical) skills.

Tuesday, October 10, 2006

Are we better off?

For thousands of years, our ancestors lived in a low-energy world. They worked the soil without the aid of powered machines, raised their own crops, and independently produced nearly everything they used. The post-Peak Oil future will require that we live similarly to our powered-down predecessors. But will we be better off than they were?

Knowledge
Without question, there is far more knowledge at our disposal now than at any other time in the past. This knowledge is our greatest ally and increases our ability to not only survive but thrive. We understand the vagaries of electricity, medicine, engineering, ecology, and even education itself that will enable us to live comfortably and sustain our environment.

Environment
Agrarians of the past enjoyed rich natural soils, unspoiled waters, and pure clean air. Obviously, this is no longer the case in most areas of the planet. The industrial period has left in its wake myriad forms of pollutants in our land, air, and water. Most surface and shallow well water (sometimes even rainwater) must be thoroughly treated before completely safe for consumption – a near impossibility after Peak Oil. Some staples of our diet, such as fish, are often highly contaminated with mercury, bromine, and other toxic chemicals. Excess fertilizers contaminate the soil and severely damage aquatic ecosystems.
The atmosphere has also seen very serious damage, particularly in the form of global warming. The coming decades and centuries will see increasingly unpredictable weather. The climates and basic ecology of entire regions will dramatically transform, driving many to disaster. For some areas, climate change may bring beneficial precipitation and temperate weather – but the net effect will be negative for humanity.

Health
Citizens of the past (and some in the present) had to contend with an astonishing array of deadly and debilitating diseases. On the whole we have learned how to treat or outright eliminate many diseases and life expectancy has soared beyond pre-industrial levels. We will carry most of this knowledge with us into a Peak Oil future and we will combine it with healthier agrarian eating habits.
Unfortunately, much of our improved health is owed to technology—particularly plastics—that is essentially gone shortly after Peak Oil. Post-Peak Oil doctors will be forced to innovate in order to maintain our current levels of health.
In addition, the intervening industrial period has introduced many contaminants into our environment which lead to many serious and difficult-to-treat conditions. The end of oil will reduce their rate of accumulation of carcinogens and other pollutants, but many persist in the environment for long periods of time.

Resources
The global population boom in the last century has put enormous demand on all of the world’s resources. Oil is the prime example, but the geologic theories of Peak Oil apply to metals minerals, water, and even salt. The key factor is that the most easily accessible quantities were obtained first, leaving increasingly inaccessible residuals available for future use.

So are we better off? The answers seem mixed. We're better prepared to handle the challenges of an agrarian life, but we face a greater number of challenges than probably at any point in human history. In some respects, the question is moot; but in others, answering the question allows us to assess what we can take from our ancestors' way of living. One thing is for certain: we will be far worse off if we don't plan carefully for the challenges ahead.

Monday, October 09, 2006

Living history, living future

During a visit home to Iowa last weekend, we took a morning trip to Living History Farms near Des Moines. It was refreshing to get a glimpse of simpler living and learn how they did it. It’s also interesting to consider how a pre-Oil way of life differs from a post-Peak Oil life. I recommend everyone take a healthy dose of the past to remember the peace of living towards which we’re working.

Thursday, October 05, 2006

Peak Oil Home Electricity Requirements (Part 2)

Smart design is about allowing for transition. Yes, appliances will eventually degrade and power sources will decrease in efficiency over time – but rather than requiring that you have all your sustainable skills and supplies in place by the time your home is built, allow time to transition from an energy-intensive life to a sustainable one. Don’t beat yourself up for using a refrigerator in your post-Peak Oil home, but learn to get by without it (e.g. using ice houses, root cellars, etc.) as part of your graduated development. Also, don’t design yourself into a corner for which you lack the skills or resources to cope.

If you design your systems to meet your current connected lifestyle with TV and computers (how else could you keep blogging?!?), when those devices are no longer useful you will gain spare electrical capacity.

This first estimate is by no means the final word on your electrical requirements. As your design matures, you may find that you don’t need anywhere near the initial estimates (after designing insulation, non-electrical heating, etc.) or that you can’t afford to generate that amount. If the latter is the case, you can fix your situation either procedurally or technically; that is, by adjusting your usage behavior or using more energy-efficient appliances.

For now, in the first design iteration, we will keep these values as test requirements and adjust things as we go.

Take a look at the numbers in table in Part 1. We can use the daily 65 kWh as-is for now, but the 27 kW of peak power is a huge figure. Already, it is obvious that running all of these electric devices at the same time is not practical (in fact, you would really have to work hard at it to run them all at the same time!) and procedural limits are required. Re-examining the list, we can see that the constantly running devices we don’t turn ‘on’ (e.g. fridge, water heater, etc.) could cause a peak of 6400 W (in the summer) if they all clicked themselves on at the same time. Using engineering judgment, we can then say that a limit of 3600 kW of transient electricity for the remaining appliances could meet the family’s needs. So for now, let’s choose 10 kW as our peak energy draw requirement.

Our second iteration on all the parts of this design will begin after we complete the other top level requirements.

Wednesday, October 04, 2006

Peak Oil Home Electricity Requirements (Part 1)

Returning to the Homestead Example Problem, it’s time to focus on figuring our electricity requirements. For this, it’s best to start by estimating high and then paring things down as we refine our design.

The following table is a rough estimate for a family of four in a 2000 ft^2 house.

Peak Wattage Usage frequency Daily energy (kWh) 600 8 hours/day 4.8 1500 10 min/day 0.25 5000 3 hours/week 2.1 2000 5 hours/week 1.4 300 1 hour/week 0.04 200 10 hours/week 0.29 300 8 hours/day 4 4500 6 hours/day 27 130 3 hours/day 0.4 300 1 hour/week 0.04 200 4 hours/day 0.8 125 4 hours/day 0.6 600 8 hours/day 4.8 600 12 hours/day 7.2 200 8 hours/day 1.6 1200 1 hours/day 1.2 300 1 hour/day 0.3 5000 1 hour/day 5 5 2 hours/day 0.01 200 4 hours/day 0.6 1200 1 hour/week 0.17 1000 2 hours/day 2 1000 10 min/day 0.17 300 1 hour/week 0.04 200 4 hours/day 0.6

Please note that I am not advocating the use of any of these items – I just want to give a complete list of the most common appliances we use today. If you choose to use a dryer instead of a clothesline, or a dishwasher instead of washing by hand, that’s fine. This is not a forum for us to judge each other, it is a forum for developing design strategies.

These numbers are first iteration estimates, which err on the high side. This serves several purposes: first, it prevents us from overly restricting the design too early in the process (remember, we are still in the first iteration of the design cycle); second, as appliances age they become less efficient.

Tune in tomorrow for Part 2 where we refine the estimate to more reasonable numbers.

Tuesday, October 03, 2006

Sustainable Industry in Wisconsin

The Madison Peak Oil Group has a post on one of the most promising stories I’ve heard in a while. Being in the aerospace industry, there are few opportunities for me to look for sustainable solutions in my job. But this gives me hope that there are possibilities I haven’t yet considered.

State firm's crane runs on veggie oil
From The Capital Times on September 30, 2006:

MILWAUKEE (AP) - A Wisconsin company is testing a
crane that uses vegetable oil to run its hydraulic lift system.

Most hydraulic systems use petroleum products that can
damage the environment if spilled. Manitowoc Crane Group
designed its truck-mounted crane to be used in or near
wetlands, lakes and other environmentally sensitive areas.

"It worked just like a regular boom truck. No problems," said
Jeff Johnson, chief operating officer of Scott Powerline and
Utility Equipment, a Louisiana company testing the crane.

Manitowoc Crane Group had been worried that the vegetable
oil would degrade or become rancid with heavy use, said
John Lukow, vice president of sales and marketing.

But so far, the test has gone well. Scott Powerline has put
more than 1,000 hours on its crane as it installs power line
polls near Dallas.

Manitowoc now plans to offer its eco-friendly crane to
others. In addition to using vegetable oil in the hydraulic
system, the crane runs on a soy-based biodiesel fuel.

The company doesn't expect the veggie crane to be a big
seller, but a spokesman said it gives construction companies
another option.

"You never know where they're going to end up, and where there
are going to be environmental options," spokesman Tom Cioni
said.

Monday, October 02, 2006

Trade studies for Peak Oil houses (Part 2)

After developing varying design concepts to meet your requirements, the next step is identifying the key characteristics of each so you can make objective comparisons. For the three design concepts in Part 1 I have sketched out the advantages and disadvantages.

Troglodyte Home:
1) High R-value (insulation) due to surrounding soil
2) Underground rainwater cistern stays insulated
3) Protected from wind
4) Low profile (security concerns)

1) External stairs could be treacherous in winter conditions
2) Snow could block vents/skylights
3) Little natural lighting (even with skylights)
4) Vulnerable to flooding (depending on topography)
5) Risky in earthquake-prone areas
7) Very uncommon design

For the Semi-Trog Home:
1) High R-value for lower level
2) Above-ground cistern allows for higher water pressure
3) More potential for natural lighting
4) More psychologically comfortable than Trog Home

1) Requires more supplementary insulation than Trog Home’
2) Above-ground cistern vulnerable to external temperature
3) Somewhat vulnerable to wind
4) Uncommon design

For the Loft Home:
1) Significant natural lighting
2) Earthquake resistant
3) Traditional framing/building techniques may be used