Sunday the Extreme Makeover‘s army of volunteers will begin construction on the 3,300 sq ft monster in Hattiesburg, MS. This will be the 167th home built by the ABC Makeover crews. My part? As the home’s green building verifier I’ll be traveling to the “Hub City” at 3:30 or 4:00 a.m. (I should have my head examined) on Monday the 7^th for the faming inspection and thermal bypass checklist…(now that should be the news story…that someone was able to get my butt out-a-bed that early for work…)    ..    then midday Monday I’ll be back here in Jackson to work with the judges in the Growing a Greener Mississippi green building contest. They’ll look at 3 homes…Scott Shoemaker’s place and Randy Berg’s two houses.  Silver Level – all three of’um.

Remember the first place builder in the contest gets 50,000 green backs. Second and third ain’t chump-change…30,000 and 20,000 respectively.

Tuesday we’re off to Oxford and Starkville. One Silver and one Gold. Wednesday we cruse down south Mississippi to Biloxi and Gulfport, again one Silver and one Gold Level to judge. Before the day’s end I’ll visit Hattiesburg again for a final inspection at the Makeover home. I’m sure I’ll be “extremely” tired by then…

Pervious concrete allows water to flow through thereby slowing down the water run-off rate.

Pervious concrete can take in storm water at a rate of 3 to 5 gallons per minute per square foot of surface area. That exceeds the flow rate needed to prevent runoff in most rain events. The rainwater may be stored in a coarse gravel layer underneath the pavement or allowed to percolate into the underlying soil. Because the pavement itself acts as a retention area, it helps to prevent much of the polluted runoff that normally occurs with impervious pavements.

Can it get stopped up? It’s unlikely that a pervious surface will become totally clogged. Reducing erosion and sediment runoff onto the pavement through good design can eliminate most problems. If any voids do become clogged, vacuuming or pressure washing of the pavement can restore most of the permeability.

What are the limitations? While this thirsty pavement is an excellent option for certain situations, it may not always be a viable choice. Because pervious concrete has a rough-textured, honeycombed surface, moderate amounts of surface raveling are normal. This can be a problem on heavily traveled roadways.

Special attention must also be given to the overall design of the pavement system in order for pervious concrete to perform as intended. Proper engineering of the substrate beneath the pavement is essential, since it must be able to temporarily store the water while it percolates into the soil. An initial soils site survey and site-specific stormwater calculations should be performed by a stormwater management engineer.

Installation: Pervious concrete is delivered to the jobsite by conventional ready-mix trucks and placed within

A heavy roller press is used to place pervious concrete.

standard forms. Because pervious concrete is thicker in consistency than regular concrete, a vibrating mechanical screed is used to level it off. Vibration is followed by compaction with a heavy steel roller to attain greater strength.

Because pervious concrete has a low water content, curing is especially critical. After placement, the concrete is misted with water and then covered with plastic sheeting and kept damp for at least 7 days to allow full hydration of the cement.

Often paving crews can complete pervious concrete jobs faster than when installing regular concrete. That’s because pervious concrete doesn’t need to be worked with a bull float or trowel, since these finishing operations can seal off the pavement surface and decrease water penetration.

More:

Ten Strategies for Ensuring a Successful Pervious Concrete Installation

Pervious concrete design ideas

Sources:

www.concretenetwork.com

http://porterworks.com/

Points: 7

Documentation Needed:

Site plan showing that no environmentally sensitive areas are present or impacted. An environmentally sensitive
area is

• any area within wetlands as defined by federal, state, or local regulations
• area of steep slopes
• “Prime Farmland” as defined by the U.S. Department of Agriculture
• areas of “critical habitat” for any federal or state threatened or endangered species.

How to Verify

Verify that the documentation shows no sensitive area or if any a sensitive area is present on the site that the sensitive area is not impacted by the development/construction.

[[Eco-footprints are only a part of sustainability]]

Expect to see this number a lot in energy discussions over the next few years: 2.5 cents/kWh. It is the average cost of energy efficiency, a figure pegged this week in a new report by the American Council for an Energy Efficient Economy. http://www.aceee.org/press/u092pr.htm.

This number is big news because it is so small.  As a resource, energy efficiency beats out all conventional power sources on price.  (See chart below.) Moreover, it’s a price that has been dropping. Five years ago energy efficiency cost 3 cents/kWh.

But just because something is cheap, doesn’t mean people will buy it. How much energy efficiency will make it into the nation’s energy shopping cart?

Efficiency boomed in the early 1990s, but then busted later in the decade when deregulation allowed many utilities to shed their efficiency programs. It is resurging now, part of push by state and federal policy makers to green and ‘smarten’ energy supply.

Most utilities do not make money on efficiency, and this is part of the reason it busted in the late 1990s. Perhaps as important, efficiency’s branding was off. It was seen as an extra, a nicety to pursue out of goodwill when a utility or state had some extra money.

ACEEE and other efficiency advocates are trying to reshape the image. They refer to efficiency as a fuel – just like wind, sun, coal, natural gas, oil. And they want efficiency to be the ‘first fuel.’ This means that when a utility is planning its energy supply, it first applies as much efficiency as is cost effective and plausible, before it builds more expensive new power. Some eastern states are already using this planning concept. In addition, many states have set specific energy efficiency goals, some very aggressive.

That is why ACEEE’s 2.5 cents/kWh becomes so important. It is a kind of marker against which other resources will find themselves competing more and more in policy planning.

Meanwhile, an increasing number of states are decoupling utility profits from kilowatthour sales or instituting other financial incentives that inspire utility support for efficiency.

Of course, our economy cannot prosper on efficiency alone, but many studies indicate we still have a lot of waste in the system.  So as an energy planner, if you were confronted with increased demand – and are not dealing with policy or system issues that require generation or transmission as a solution – which of these would you pursue first?

Credit: Cost figures from ACEEE, “Saving Energy Cost Effectively: A National Review of the Cost of Energy Saved through  Utility Sector Energy Efficiency Programs,”  September 2009, http://www.aceee.org/press/u092pr.htm.

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Lisa Cohn of Energy Efficiency Markets interviews Ujjwal Bhattacharjee, a principal consultant with PA Consulting Group who specializes in renewable energy and energy efficiency. He evaluates energy efficiency in Massachusetts green buildings from 2004 – 2007.