Setting Priorities for your Sustainable Home Design is the Key to having a Green Home

If sustainability is one of the goals for your building project, then a sober assessment of priorities will help to guide your selection of green building technologies.  Whether your project is a new construction, remodel or renovation, the sustainable identity of your home will only be genuine when its components and elements furnish positive returns on investment.  Unfortunately, the most visible and showy applications may offer the least value for supporting sustainability.  Solar collectors and panels can be exciting and enticing.  Unfortunately for our egos, it is most often the very common (even dull) conservation measures which furnish the biggest bang for the buck.

Conservation

A bit of clever design can find much opportunity for energy savings through conservation methods such as thick insulation, secure air barriers and construction detail which are carefully considered and executed.  Tight high quality windows and doors can reward investment.  Caulking and weather-stripping can be the most boring, but the most effective means of saving energy.  Don’t forget the lighting.  CFL and LED lamps can reduce electrical usage.  These and other basic conservation techniques should be the first considerations.

Passive Solar

The next most effective resource-conserving approach is passive solar architecture.  If your home is located at a site with southern exposure and in a cold climate, then a passive solar orientation can provide significant financial savings with little added expense.  Such application can be as simple as arranging more glass on the south side of the house than on the other sides.  If the sunshine entering these windows lands on masonry surfaces, then energy can be stored by day and slowly released during evening hours.  Modest overhangs will shade the heat gain during winter and allow the sunshine to enter during the winter due to the seasonable changes of the sun’s motion.  The simplicity of such designs is appealing.  Passive solar architecture can be accomplished without moving parts (except for the sun) and is therefore affordable and reliable.

Passive Solar Home Design

Active Solar

Finally, for those who have taken advantage of all of the above opportunities and still wish to venture further into sustainable home design, then active solar collection systems may be appropriate.  These will include photovoltaic power generation and domestic water heating systems.  In locations where water is scarce, rainwater harvesting and grey-water recycling may be employed.   All of these installations however will represent significant investment and financial returns must be carefully examined to determine if they are economically justified in each particular application.  Tax credits and deductions may be available for these systems (as with conservation and passive solar expenses) and these incentives will vary from region to region.  Full financial analysis can be complicated, and solar panel installers can often lend helpful support.

PV Solar Power System

By establishing priorities, your project will follow sound principles that lead to architecture with integrity.  You will be assured that the green building measures employed in your sustainable project truly support your commitment to conserving energy and other resources.

Some of the more heavily discussed topics of early 2010 include renewable energy, green infrastructure, clean water, and more. In particular, the addition and/or substitution of green spaces has been quite controversial as of late. Senior resident of Urban Land Institute Ed T. McMahon states “Green space adds value to property.” Not only would these areas of conservation drive economic trends upward, but they also improve the overall health of the surrounding community. For example, substituting things like golf courses for conservation areas would essentially increase surrounding property value while diminishing overpriced maintenance fees. The same holds true for airports and other large acre-eating developments.

Some of these areas are already abandoned or unkempt. For instance, park and recreational areas that were once highly visited have become urban wastelands. In an article from the Salt Lake Tribute, Lindsay Whitehurt discusses how an area that was capped with tennis courts to replace an old reservoir had been empty for some time now. She further explains how the University of Utah received a loan to fill the old reservoir and turn the land into a conservation area.

Much larger metropolitan areas are also playing their role in promoting sustainability by implementing many Green Spaces within the city. In Meg Muckenhoupt’s new book Boston’s Gardens & Green Spaces, she discusses different green space within the city of Boston. With very low cost maintenance fees and little liability, these areas are perfect for protecting our wildlife and the environment. They also attract further tourism; which would in turn generate revenue from ticket/tour sales.

This aligns with the implications of “economic viability” and long term sustainability, posing the questions, “Would substituting golf courses and airports in the short term lead to an abrupt economic downfall? It’s true that this type of architecture provides undoubtedly high revenue. On the other hand, they both come with ridiculously high expenses and maintenance. Incorporating various elements of green architecture implies things like green roofing, which could in turn drive down electrical/gas costs dramatically.

Larger organizations are already taking a step in the right direction in Haiti. Machine behind the CGI (Clinton Global Initiative) Doug Band has been working closely with organizations like AFH (Architecture for Humanity) to discuss potential means of green restoration. Combined with the additional efforts of many large collaborative units like the USGBC (United States Green Building Council), they plain to rebuild Haiti in a greener fashion.

Recent findings have driven people like McMahon and fellow conservationists to investigate further into upgrading and expanding green infrastructure efforts. As earth day 2010 slowly approaches, it’s important that we as individuals follow and support these ventures. It’s equally important that we adapt greener disciplines to support both our planet and our economy.

It was a great Columbus Day weekend in Washington DC, and Solar Decathlon was making waves on the news… Well, actually it did not. Not even bigger green sites and blogs covered this truly green event. Probably there were much more important things happening in our capital – like Obama’s newly “adopted” dogs .

So I’ll let the big guys do their things, while I tell you about the event, which so many people waited 2+ years for, and worked so hard to make it happen – ladies and gentlemen – Solar Decathlon 2009!

This was our first Solar Decathlon, but certainly not the last. Since we were sponsors of Team Boston Solar Home, most of my coverage will be focused on it. However, there were many great solar homes this year: Team California and Team Germany were battling for first place (you can see Team Germany solar home in the picture above – a black house, second from the right).

As I wondered through the Mall, looking at these homes and being hesitant to stand in line to see very similar interior set-ups, my main focus was on the outside. Solar technologies, energy efficiency and exterior design were my main concern, as these factors make a true solar home, while the inside can always be remodeled.

Team Boston Solar Home:

As a future architecture student, and a “construction worker” now, I look at these houses with a slightly different perspective than most people. For me, the ease of construction, most energy efficiency and reasonable cost are the most important things, followed by a nice design. Unfortunately, many of the innovative approaches used for this competition, are not accessible to the masses, and remain to be a privilege for the most extravagant home buyers with deep pockets. While I have no problem with it in general, in my opinion, the purpose of a Solar Decathlon is to move innovative green building technologies into the mass housing market, so that such technologies would actually make a major difference in improving the environment and reducing CO2 emissions.

It is expected of all these homes to be super insulated and have solar PV panels on their roof. I was interested in innovative new approaches at achieving maximum effect (energy efficiency or energy generation) using the least expensive methods. In this regard, the Boston Solar home has (had) great potential, if not for the massive glass array on the northern side of the house. All these windows and doors will let all the heat escape in the winter, which makes it that much less efficient. This is a fixable situation however – just remove most windows and put a wall there

Despite potential heat loss, the liquid-filled glass units on the southern side of the house will collect tremendous amounts of solar heat and store it, making it much easier to heat this house. Find out more about these liquid-filled solar thermal windows and wall panels.

In addition to solar thermal wall panels, Boston solar home has about 6.4 KW solar pv system on the roof and a solar thermal hot water heater, for heating and domestic use. There are many other new and innovative design features used by BAC (Boston Architecture College) and Tufts University students in the construction of this home – too many to list here. You may check out the project’s website – www.livecurio.us.

Team Spain solar home:

Another solar homes that attracted my attention was the one build by Team Spain (which for some reason was doing VERY poorly in this competition).

Apparently, these bi-pv cells are very good at capturing indirect sunlight and help the house generate the most electricity it possibly can.

Team Spain used a very interesting )in my opinion) approach at capturing ALL available solar energy with their powerful solar PV array. This roof mounted array can rotate at the center, following the sun going across the sky, thus always keeping the most efficient angle of the PV panel to the sun. It is basically a gigantic solar tracking system, which is however complicated and expensive systems to implement, which make this house not as competitive in terms of costs and ease of building.

Additionally, the glass walls of this home have integrated solar PV cells, which captures even more solar energy. It is a good idea, but and overkill in my opinion, and the roof mounted solar system should be more than sufficient and, unless they used “dummy” cells on east, west and north sides of the house, it is a waste of solar capacity, as the sun will barely or never hit those solar cells.

Cornell University Solar Home:

Another interesting design, which for some reason reminded me of the Water World movie was a solar home built by Cornell University students. It featured three round “rooms” connected to each other, and a large solar PV system, which for some reason was mounted flat to the ground.

It may not be the best designed house (in terms of competition rankings), and round rooms make it ever more difficult to build, but the steel frame and a VERY cool vintage design made it very attractive. As I was writing this, Cornell’s solar home was in 6th overall place, with a few more contests to go. You can view current team rankings here: http://www.solardecathlon.org/scoring/

As a side note, as of Oct. 13th, Team Boston solar home is in 12th position and Team Spain is in 18th place, while 1st place belongs to Team California.

Let the best solar house win!

The Solar Decathlon will continue for another week or so, and there are a lot of contests left in which either team can pull forward dramatically. Therefore, I will not even try to predict the winner. All houses presented in the Solar Village this year were very well designed and built, and the green building technologies used in them will in the (hopefully) near future migrate into traditional construction markets and help home and building owners reduce the over all energy use and make our environment better. This competition is also an inspiration for the new wave of architects who will be literally building our future homes and infrastructure, and as you can see, they all have great ideas. I will continue the cover the Solar Decathlon 2009 in future posts, and soon you will be able to review the IB flat roof installation which we did on the Curio Home – look forward to seeing it soon on our cool roofing blog.

In October 2009, the National Mall in Washington, DC will be turned into a “Solar Village”, where 20 contemporary solar homes from all over the US (and one solar home from Germany), will be on display to demonstrate all the latest and greatest in green construction, and renewable energy. This is the Solar Decathlon 2009, a bi-annual event sponsored by the US Department of Energy, many colleges and universities, as well as private businesses specializing in green buildings.

In 2007 Solar Decathlon, Boston was represented by a Solar Home built by the MIT team and many volunteers interested in green technologies. This year it is Boston Architecture College and Tufts University that sponsor the solar home built by Team Boston. Why team Boston? Because many folks that participated in the 2007 Solar Decathlon are doing it again.

We and IB Roof Systems (the manufacturer of Cool PVC flat roofing membrane) had our own humble involvement by sponsoring the roof installation on top of this amazing creation of the latest architectural designs and green construction technologies. Now, with a new IB 50-mil PVC membrane, this solar home will be completely water-tight and the built in water collection system will provide it with as much H2O as needed. The roof is also very well insulated with over 5 inches if rigid ISO tapered insulation and additional 12 inches of insulation between the rafters. The cool roofing properties of IB Roofs will minimize its cooling needs, and will waterproof the entire building. Hopefully everyone will be eventually replacing their old black roofs with cool roofs such as IB. Also, when roof removal is required by code, calling a skip hire to remove the old material, and then installing these new highly efficient roofs is an economical and sustainable way to deal with roof tear-off. In some cases, the old asphalt roof can be recycled and used in synthetic roofing products.

About the Team Boston Solar Home:

By definition, a solar decathlon project will use different solar technologies available on the market. Team Boston has created such a design where virtually every solar system has been be utilized. There will be a 4.6 KW Solar PV system consisting of 20 SunTech PV panels. There will be a large solar hot water installation using Viessmann Solar Thermal hot water panels and water storage unit. But aside from these common, roof mounted solar systems, there will be a new solar thermal system, that will provide up to 70% of FREE heating to this house. It is a so called “trombe wall”. I’ve discussed it in our previous article about solar thermal mass windows. But this time, the Boston Solar Home will have new and improved solar thermal windows: these are not the old 2×2′ window blocks. It will be a full size 8×2 wall/window units, covering the entire south side of this solar house to provide it with all the heat it will need in the winter. To avoid overheating in the summer, the roof will overhang the southern side by 3 feet, and an additional retractable awning will roll out to provide the shade for these thermals walls / windows.

The walls of this solar house have 2 inches of ISO insulation on the outside and 6 inches of between studs insulation. In total, there will be more than 30-r in the walls. Although this is a stick construction home, it can easily be labeled as super-insulated, and it will have minimal heat loss, while providing more than enough energy to be completely off the grid, and won’t need any outside energy sources for either heating or cooling.

Portable design of this Solar Home:

For the purpose of the competition, the house has to be transportable, therefore it is designed and built in 3 sections on portable foundation blocks, so that it can be put on flat-bed trucks and transported to DC for the competition, and then transported back.

The house is designed to be easily taken apart and put back together: All the mechanical components, bathroom, kitchen, heating and air-conditioning equipment and electrical panels ate located in one part, and special quick connect ports are used when two living sections are connected. Solar PV panels and solar thermal system are installed on removable racking systems that are mounted to the parapet walls on the roof, eliminating any roof penetrations and potential roof leaks. This also allows for easy removal and re-installation of both types of solar systems.

There will be a fold-able / removable deck / patio area with a handicapped access ramp, making this home a perfect choice for comfortable living in the summer and winter, and usable by anyone.

Final thoughts about the solar house:

Since this solar home is still in the construction stage and many systems are not installed yet, it is difficult to get a complete picture of how it will perform. Still, this will be a true zero-energy home, and will actually produce a lot of excess electric power to be sent back into the grid. My biggest personal concern about this home is the cost: without having the exact information and costs run down, the estimates are around $800,000. This amounts to about $1000 per square foot of living space (a maximum of 800 sq. ft. of living space is one of the guidelines of the Solar Decathlon competition), which is very expensive and is not very practical. However this is just  a prototype and if it was a mass production home, the actual cost would be a lot less. This cost also includes the transportation to and from the competition site in Washington DC, and nominal expenses such as marketing, promotion, creation of the website, etc. So the actual construction costs are somewhere around $500,000-600,000.

This is just the firs report on this solar home, and there will be more, as construction goes on. Stay tuned for a complete report on the roof and solar PV system installation, as well as overview of the new solar thermal window units.

Useful resources:

http://www.coolflatroof.com/flat-roofing-blog – Learn about the green cool PVC roofing systems, solar roof products and metal roof installation methods.

http://www.mbmcarpentry.com – Green construction and home improvement in South-Eastern Massachusetts and Rhode Island.

MA Metal Roofing – Flat roofs will not always fit the design of a solar home, and that is where the greenest roofing technology – a Metal Roof – is a perfect fit for any sloped roof design.

The most economical Solar Roofing combination is to use a Standing Seam Metal Roof with Thin Film Solar Panels – a practical and sustainable option for residential Solar PV installations.

In this solar roofing guide you will learn about pros and cons of metal roofing with laminated thin-film solar PV panels manufactured by Uni-Solar Ovonic, or simply UniSolar which is an Energy Conversion Devices company/brand.

UniSolar thin-film solar panels have been specifically designed to be installed with a standing seam metal roof and have a nominal width of 15.5 inches, which fits perfectly into a 16″ standing seam metal roof panel. With a special butyl adhesive backing, the installation of thin-film solar panels is very simple and fast.

Watch how the the solar metal roof is installed and how solar panels start producing free electricity right away:

Solar Metal Roof Installation video:

Benefits of Solar Metal Roofing and roof-integrated solar systems:

Solar metal roofing is the most cost effective way to get a lifetime roof installed together with a solar PV system. The saving comes from the fact that the installation of the solar system is greatly simplified, because there is no need to install the racking system, which holds conventional solar panels. This saves you about $1 (one dollar) per watt DC of solar system, and eliminates an additional $.50 per watt for the installation of the racing system and solar panels. With thin-film solar PV laminates, the installation is reduced to cleaning the inside of the metal roof panel, applying and rolling in the solar PV laminate and installing the metal roofing panels.

Later, when all the standing seam metal roofing panels have been installed, the solar integrator connects the mom and pop contacts on each solar panel to form one, two or more strings of solar panels, and runs the wiring down to the inverter, which then converts the DC power from solar panels into AC power at 240 volts and feeds the electricity into your home’s power network. All excess electricity is sent into the grid (for grid-tied solar systems), or to your storage batteries (for off-grid solar systems). You can use solar calculator to estimate the cost of solar system and calculate solar roof price

Why use roof-integrated solar system vs. conventional solar panels?

The main problem associated with general Solar PV systems that you can now see on many homes around the country, is the fact that an asphalt shingles roof will fail much sooner than the Solar panels. When that happens, those home owners will be faced not only with the re-roofing expense, but also with complete removal of the solar array and re-installation. This MUST be performed by both the roofer and the solar integrator, as the roofer alone will 99% of the time screw things up. And bear in mind that a roofing warranty will usually not cover damages to the solar equipment, let alone all the possible short-circuit type situations.

The additional cost associated with these procedures should be at-least the same as the cost of the new roof itself. Think about it: Electricians unlike roofers have to be licensed. An apprentice electrician needs at-least 4 years of schooling/work experience. This is like an undergraduate degree. A master electrician needs another 4 years. Therefore, electricians usually charge $75-100 per man-hour. You’ll need at least two electricians for this job, which will take a whole day to remove the panels and another day to put them back, if not more.

The math is simple: 2 guys * $75/h * 8 hrs. * 2 days = $2400 plus any possible parts and supplies that may be required. So let’s say it costs you $2500 extra. In some parts of the country that is how much an average 1200 sq. ft. cape house roof will cost today with the material.

Metal Roofs vs. Asphalt shingles

Unlike very “popular” asphalt shingles, metal roofs are pretty much permanent. They are for the most part, produced from recycled metals, and when installed by a trained professional, they will not leak for decades. Read more about residential and commercial metal roofing .

Metal roofs combined with Renewable Energy technologies can create a perfect combination of light, long-lasting and affordable solution for Solar Electric and Solar Hot Water, as demonstrated in the image to the below:

There are other numerous benefits to having a metal roof combined with Solar PV and other renewable energy technologies. When looking at a metal roof vs. asphalt shingles, also consider that a metal roof will save our land fills from getting more shingles dumped there in 10 years or so. Combined with beautiful looks, you get a permanent roofing solution, various solar technologies, and when paired up with a geo-thermal system, you can easily design a 100% energy-free home, with great curb-appeal.

Check back in a couple of weeks for a complete Solar Metal Roofing Guide.