The Value of Walkability

Transportation is a huge part of the equation of sustainability.  It’s an issue that hits home.  Considering both financials and the environment, what is it worth to be able to get around without a car?

First the financials.  These days Americans drive on average 13,476 miles each year. Assuming a cost of $0.55 per mile driven (IRS mileage rate — a AAA study showed costs ranging from $0.38 to $0.98), the cost of that driving habit is $7412 each year, or $618 each month.   Making the commitment to get around by walking or biking, means that $7412 saved each year can be put to other things.  Like solar panels!

Now the atmospheric impact.  Each gallon of gasoline burned produces at least 14 pounds of CO2.  Those 13,476 average miles driven, in an average 22 MPG fuel-efficient car means 5.21 tons of carbon dioxide is contributed by each driver to atmospheric greenhouse gases.  Getting rid of one car and going with a walking or biking lifestyle, would reduce the disproportionate environmental impact of an American of 16.9 tons/year by almost one third, and bring it more in line with the impact of a European.

Of course it helps to live in an area where its walkable.   For any residence you may be considering renting or buying, you can get a walkability rating from  The website looks for common destinations, like grocery stores, drug stores, restaurants, parks, libraries, etc. and gives a rating from 0 to 100 on how many of these are less than one mile away — or ideally less than a quarter mile away — with 0 being totally car dependant, and 100 being the most walkable with everything one needs in life a short walk away.  According to, Seattle overall is the 6th most walkable city in the US, with an average walk score of 74, meaning “very walkable — most errands can be accomplished on foot”.

If the cost savings and environmental benefits aren’t already enough, several organizations are offering incentives to people willing to get rid of one car for at least a year in a “One Less Car Challenge” in Seattle.  It’s a cold-turkey approach which may be intimidating for most people.  In my own life, I got into the mode of walking and biking for transportation gradually.  It took re-thinking my expectations, habits, timing, and clothing.  It’s a great way to stay fit, have contemplation time, and feel connected to the community.  I put a high quality-of-life value on walkability!

Solar Electric Production Exceeds Expectations!

As a brand-new owner of a solar electric system, of course I want to know how it is producing — whether it is on target for producing 90% of the expected electrical use of the house.  The good news is that it’s on track for 100%!  I say this with only 6 weeks of data to look at.  What makes this estimate seem reasonable is the fact that the Autumnal Equinox is within those 6 weeks.

One of the biggest factors which affects the electrical productivity of a solar PV system is the length of day.  The longer the time of daylight, the more energy that is produced. In Seattle day length varies from a maximum of 16 hours in the summer to the minimum of 8 hours in the winter.  Midway through the year at the start of Spring and Fall, the day and night is about equal, at 12 hours of each.

You can never really know exactly how much electricity a solar PV system will produce in a year until it has produced it.  And it may vary year by year because of other factors, like weather and dust and debris accumulation on the panels.  However, in an attempt to predict how our new system is doing, I have taken a sample to extrapolate.  I chose Sept 7 through Oct 6, a 30-day period with the Autumnal Equinox in the middle of the time period.  The graph below shows the length of day and night on the 21st day of each month and the sample range between the red lines.

Amount of daylight for "average" month

30-Day Period (Sept 7 thru Oct 6): Averaging approximately 12 hours of daylight each day

During this 30-day sample period, the system produced a total of 433 kWh.  The best day produced 19.2 kWh, the worst day only 3.9 kWh, the average was 14.4 kWh.  Assuming this period is an “average” month for daylight, by multiplying this value by 12.16 (to get the 365 days of the year), it would seem to indicate the annual electric production potential.  This would mean annual production of 5,265 kWh.  That’s 100%!!!

Looking at one year of utility bills, the annual electrical use was 5,242 kWh.  The solar PV system was originally designed for an annual target of producing 4,536 kWh, or 90% of electrical use. But the installers unexpectedly upgraded a few panels to higher efficiency panels.  And could it be that September being historically the driest/sunniest month of the year in Seattle it’s not an “average” month for weather?

Call me an opptimist, but it’s fun to think it may turn out that the house electricity is 100% solar!  Net Zero Energy, here we come!



Oh, the joy of seeing the electric meter run backwards!

There are 3 major benefits to having a grid-tied solar electric production system, rather than being totally “off the grid”:

  1. You don’t have to purchase and maintain a set of batteries (save money!).
  2. You don’t have to find a place in your house to put all those batteries.  (save space!)
  3. You get the joy of watching your electric meter run backwards (joy!).

“Net Metering” is an energy swapping deal with the electric utiltiy company.  They take your extra electricity when you don’t need it, and they give it back to you when you do need it.  When your solar PV system is producing more electricity than you are currently using, the extra energy goes onto the utility power grid.  The electric utility company then sells it to your neighbors.  Then when you are using more energy in your home than the solar PV system produces, the extra energy you need is pulled from the from the grid.  The electricity you buy from the electric utility company at that point is free — until you run out of your solar production credits.

You’ll tend to produce extra during the daytime, and draw on your credit at night.  Overall you’ll be accumulating credit during the summer, and drawing down your credit through the winter.  In Seattle the days are so long during the summer that it produces enough during those few months to power a house through the rest of the year — even if the rest of those months are dark and rainy.

I have personally found the joy of seeing the electric meter run backwards so satisfying, that I have noticeably changed my electric use habits almost overnight.  I am much more conscious of my energy use.  I am much more likely to turn the lights off when I don’t really need them — when I can see by the light coming through the windows.  Our system was designed to meet 90% of the expected annual electrical use of the house.  I’m finding myself semi-consciously motivated to have this 90% system cover 100%.  It’s a bit irrational, but even when I’m somewhere else I find myself turning lights off!

Experience the joy for yourself!  Watch how it looks when the electric meter runs backward.  Click below to see a 25-second video:

Net Metering – meter running backwards!

Net Metering

Click to see the video of the meter running backwards!





Water and Sustainability: The New-Old Idea of Rainwater Harvesting

Americans have come to take for granted the abundant clean water which so conveniently pours out from our faucets. Drinking water seems so abundant here we often let it just run down the drain unused without even giving it a second thought.  In developing countries people are sometimes painfully aware of how important and valuable water is.

Seattle-ites get pretty tired of the rain sometimes. How could wet rainy Seattle ever have a water shortage?  The fact is there have been many water shortages during the summer months when demand for water is higher and rain is rare.  Since the droughts of the 1980’s water use restrictions and new tiered water rates have encouraged a change in how we all use water.  The most noticeable difference in Seattle is that it has become socially acceptable to let your lawn turn brown during the dry summer months. Those who still keep their lawn green may pay almost 3 times as much for each extra gallon of water!

The newest culture change for water conservation is the advent of the rain barrel.  Across the country, cities are doing pilot programs for encouraging rainwater harvesting using rain barrels.  The idea is for people to collect rain water from roof downspouts and use it for watering their outdoor plants to relieve some of the strain on municipal water supplies.  City employees wondered whether people would go for it.  The surprise has been how popular the programs have been!

Rainwater harvesting in Seattle

Industrial-strength cisterns store rain water for use by gardeners at a community garden in Seattle

There’s nothing new about rain barrels.  Rain barrel technology is as old as barrel technology, although there have been some minor refinements with newer matterials. Ultimately it’s a new/old idea that is catching on because of a new awareness of how valuable water really is.

wooden barrels being used as rain barrels

Wooden rain barrels and wooden downspouts in historic St. Charles, Missouri


Structural Sustainability: Doing a Home Earthquake Retrofit

A house really isn’t very sustainable if it falls down and has to be rebuilt!  When upgrading an older house to 21st century sustainability standards, it makes sense to do an earthquake retrofit as part of the project.  While nothing can ever completely guarantee any building will survive an earthquake, doing a few things can make a big difference.

Hiring someone to do the work on an earthquake retrofit for you can cost many thousands of dollars, but could prevent significant damage to your home which may not be covered by your home owners insurance.  Or you can do the work yourself for a few hundred dollars in materials, plus some sweat and effort.  It can be dirty uncomfortable work, but it’s not difficult.

Back when craftsman bungalows were being built (and other classic houses), building designers made the false assumption that the downward forces of gravity alone are enough to keep a house on its foundation.  So there was nothing really connecting the wood frame of the house to the concrete foundation wall beneath it.  This is generally true for mid-century and earlier houses.  Unfortunately, during an earthquake other forces are at work — the shake, rattle, and roll of a seismic event — which could cause a house to fall off its  foundation.  When that happens, the structural damage throughout the house might be too much to try to repair it.  A total rebuild might be required.  NOT very green!

The first step in doing an earthquake retrofit is to connect the wood frame of the house to its foundation with anchor bolts.  Holes are drilled through the lower-most wood piece (the sill plate) and into the foundation wall with a rotohammer.  Then the anchor bolts are pounded down into the hole with a sledgehammer until they are snug against heavy-duty square washers.


earthquake retrofit anchor bolts
Anchor bolts and square washers installed in the sill plate of a basement pony wall. The bolts connect the house wood frame to the concrete foundation wall as a critical part of an earthquake retrofit.

The short “pony walls” of the basement need to be strengthened structurally, so the house won’t twist or sway on top of its foundation.  The most common and least expensive way to reinforce these walls is to cover them with plywood sheets.  Nailing every few inches on every part of the wood frame creates a stiff structural panel resistant to seismic motion.  Nails are used instead of screws because they flex and don’t break under stresses.

Structural reinforcement of basement walls

Plywood sheets nailed to wood framing creates a structural panel resistant to seismic stresses.

The first floor of the house needs to be connected more securely to the strengthened basement wall, so the first floor doesn’t fall off.  Metal framing clips are put on top of the wall, and nailed to both the top of the basement wall below, and the joist for the first floor.  A palm nailer is an extremely helpful tool in this process!

Reinforcement of structural beams and posts

Reinforcement of structural beams and posts

Other reinforcement include nailing metal framing clips to posts and beams to keep these important internal stuctural members connected during a seismic event.  Then connecting the water tank to something structural with metal straps to prevent it from falling over.  All the above steps I have been able to accomplish with some help from handy family members — with training and tools from the Phinney Neighborhood Association and with a couple of hours of consultation from a specialized contractor on design, plans, and permitting.  The project was done in two phases, with each phase taking two weekends of work.

The third and final phase will be to remove the furnace chimney from the center of the house.  Chimneys can topple during earthquakes, causing damage to the roof and anything and anyone below.  Plus after nearly 100 years, the brick mortar has deteriorated to the point of being problematic in other ways.  Originally built to exhaust an oil-burning furnace, it’s time for this relic of the oil-era to go!  But that will need to be done as part switching heating for the house and water to renewable energy

Shades of Green: Measuring Success in Sustainability

How green is your sustainability project?  Says who??

In the field of sustainable building, rating systems and certifications have been springing up in abundance in the last few years.  There are so many systems for measuring “green” that it’s hard to know which one to use.  All offer extensive checklists, weighted points for doing different things, and require applications and large payments to get their certification.  All have standards for both new construction and retrofits of existing buildings.  Going through the certification process earns the building owner public-relations kudos and maybe a link on the certifier’s website.

Here are the sustainable building rating systems used which I have found so far to be commonly used in the United States:

LEED (Silver, Gold, Platinum) – Developed by the US Green Building Council in Washington DC, LEED (Leadership in Energy and Environmental Design) is perhaps the best-know rating system in the US.

Green Globes Green Building Initiative – Coming from the UK to the US via Canada, the Green Globes system of 1 to 4 offers “a streamlined and affordable alternative to LEED”.

BuiltGreen – A local Seattle-area rating system developed by the Master Builders Association of King and Snohomish Counties using 1 to 5 stars.

Passivhaus – PHIUS+ projects follow a German standard for airtight super-insulated buildings for ultra-low energy use.

Net Zero-Energy Building and Living Building Challenge are two related standards developed by the International Living Future Institute.

While many of these rating systems have a lot in common, proponents of each of these approaches seem to occasionally have differing and sometime conflicting opinions on what is or is not sustainability.  Behind each certification system is a different philosophy with slightly different priorities.

Shades of green

Shades of greens near Rifle, Colorado

Fortunately, as nature shows us, there is room in this world for many shades of green.

Today’s Solar PV Economics: Buy 1, Get 2 Free!

… and maybe get another 2 or more for free after that!

Once upon a time, it took at least 20 years to get your investment back on the purchase of a solar photovoltaic (PV) system.  The cost of the solar PV systems has been coming down, and state and federal incentives have been increasing to the point that at least in the state of Washington the cost can be as low as an 8-year return on investment.  That makes it a buy-1-get-2-free deal!  In other words: Buy 8 years of electricity, and get 16 years of electricity for FREE!  And that’s just during the 25-year warranty period.  There’s every reason to beleive the equipment should last another 16 years or more after that with minimal maintenance.  So that would mean getting another 16 years of electricity (or more) for free after that!

Solar panels on west-facing roof

Solar panels on west-facing roof

After talking with several different solar electric installers, and carefully considering the options, we chose Oregon-manufactured SolarWorld solar panels with microinverters by California-based Enphase Energy, installed by West Seattle Natural Energy.  While this grid-tied system combination does not take full advantage of the made-in-Washington renewable energy production incentives, it more than makes up for it in low initial cost, length of equipment warranty, and elegance of the installation.  A big selling feature was not requiring any equipment to be installed inside the house — which might constrain future remodel possibilities.  But we especially love the technology which constantly monitors and reports on the production of the system.  We can take a peak at how our PV system is doing through the internet from anywhere in the world.

See for yourself!  Click here to view the Solar PV system performance for the “Green My Bungalow” house.  There are 6 solar panels on the south side of the roof, and 10 panels on the west side.  (Apparently west-facing roofs are almost as good as south-facing roofs for solar electric production, because the vast majority of sunshine in northern areas is during the summer when the sun is high in the sky and the long days mean lots of western sunshine in the afternoon and evening.)  The Enphase Enlighten website shows graphs from daily to lifetime electricity production, and sends email notices to us when there is a problem with the functioning of the system.  I’ll be watching carefully, as I learn more about the day-to-day practical realities of owning a solar-electic system.

Step 1: The Home Energy Audit

It seemed logical to officially start the “Green My Bungalow” retrofit project by doing an energy audit on the house.  The idea was to have some baseline data on the current energy use of the house as a starting point, and see what recommendations the auditors might make.  A grant-funded non-profit organization called SustainableWorks is currently offering CityLight-subsidized home energy audits for the bargain price of $95.  Normally closer to $600, the audit was a thorough inspection of the energy use of the house, from attic to basement and everything in between.  The most exciting part, of course, was the blower door test, in which a large fan is placed in an exterior door to draw air out of the house.

Energy Audit

Blower Door Test for Energy Audit

The blower door test is like having all the bathroon fans, the kitchen fan, and the dryer on all at once, sucking the air out of the house, creating negative air pressure inside the house. As a result, outside air comes into the house through tiny and not-so-tiny leaks in the exterior walls, doors, and windows.  A special infra-red camera sees the temperature differential where the outside air is entering the house.    The energy audit took the inspectors several hours, and they concluded with a 16-page report.  Overall the house was rated as using slighly less energy than the average house for the area.  The report included ideas big and small for improving energy efficiency in the house.

Earthship Biotecture: The Quintessential Green Building

Many different types of “green” buildings have been developed since the dawn of the environmental movement and it seems new design concepts are springing up every day.  But so far Earthship Biotecture continues to win my personal all-around sustainability award.  Invented by Michael Reynolds and evolved over several decades, the earthship form of building gets high marks in just about every category of green. Building materials are recycled, renewable, local, low-energy-use, and non-toxic.  Building energy is renewable, energy use is extrodinarily efficient, and water-use efficiencies are off the chart.

Earthship biotecture

An earthship in Taos, New Mexico at the Earthship Biotecture company’s visitor center

I consider earthships to be the quintessential green building form.  Beyond “net zero”, they are totally off-grid in every way — power and water systems.  The combination of passive solar and heat-storing massive ground-insulated walls solves the problem of space heating simply and inexpensively.  The rainwater collection and grey-water recycling systems provides abundant water in even dry climates.  Wind and solar electric systems easily power the lights and appliances.  Best of all, the technology and building technique for earthships is simple enough for motivated people to build themselves, inexpensive enough for the developing world, yet they can be elegant enough for the most sophisticated tastes.

From what I know about earthships, the main drawback is that they tend to need large building lots, which makes them well-suited for remote, rural, or suburban areas, but not so well-suited for dense urban areas.  And that means being dependant on cars for transportation.  If I wanted to live in an area where the house lots are large, I would definitely consider building an earthship. But I love the convenient walkable lifestyle of the in-city neighborhood, where a car is rarely needed.  I just can’t see an earthship working on a 35-foot-wide urban lot.   And when it comes down to it, I love my craftsman bungalow and the traditional neighborhood setting and would be sad to leave it!

While an earthship may be in my future someday, it won’t be in the near future.  In the meantime, I will have to settle with doing a sustainability refrofit on a stick-built house on a 35-foot lot.

What Does “Green” Really Mean?

We hear this term “green” in so many advertisements and communications.  It seems everyone is being encouraged to be more “green”.  But what does “green” really mean?  I think of being green as making conscious choices to do what seems to have less impact on natural systems than the standard practices of the day.  It means taking steps to use less energy, burn less oil and coal, send less garbage to the municipal landfill, and cause less loss of wildlife habitat, and using resources at a sustainable rate.  When it comes to house construction and remodeling, it can also mean using fewer toxic materials which might affect indoor air quality.  To “green” (using it as a verb), means to consciously weigh each of these factors when considering every element of a house.

In the spirit of a environmental science project, I will try to “green” every element of my house:  interior finishes, electrical use, space heating, water heating, refrigeration, cooking, water and waste water, food production, solid waste, landscaping, wildlife habitat.

Another different but common use of the term “green” relates to economics.  Green is the color of money.  The environment and the economy have an inherent relationship.  So another element of sustainability in the Green My Bungalow project is financial.  Whatever “green” improvements are made, they also need to make financial sense.  But in the spirit of going green, I’ll need to also think outside the box of conventional wisdom in financial justification.  I will apply long-term, systemic, sustainable thinking to the financial side of the equation.  I have to beleive that if it makes sense for the sustainability of the natural environment, it must also make sense financially, one way or another.