Here's an item from the Green Built Home checklist and the corresponding explanation from the verifier's manual:

C.35 (2) HVAC supplies and returns are fully ducted (no use of building cavities).
It is recommend that supplies and returns are fully ducted (using sheet metal). Using building cavities for duct work is not recommended because usage can develop large resistance to flow, has a greater potential for leakage, and air quality issues can arise -- as there's usually construction debris present and the wood supports could develop mold if wetted.

In addition to energy efficiency, we are also focusing hard on indoor air quality. In typical construction the air returns are bounded by studs and the back of drywall, i.e., the building cavities.  Matt worked with Modern Heating & Cooling to arrange for sheet metal stacks to be installed for these air returns, which we expect will give us cleaner and better indoor air.

Ring up another 2 points for a healthier house!

Matt met with Jason from Alpine Insulation at the house today to confirm everything, and the insulators started to hang the fabric to hold the blown-in insulation in place.

Since this was my last chance, tonight I did something that I would strongly encourage any homeowner (or builder) to do.  Take detailed pictures of every wall before the insulation and drywall go on so that you can locate electrical wires, plumbing, ducts, and atypical framing in the future when you need to drill or nail into the wall for any reason. In addition to the practical value, it reduces future waste (less "test holes" or outright drywall rip-outs to replace) which is why we listed it on our green built checklist as an innovative idea.

Here are some of the detailed photos, which double as photos of the insulation preparation that was installed today.

Today the framers finished off the deck and built the deck stairs.

They also created the frame for the bathtub in the upstairs master bathroom.

The HVAC folks routed the bath fans up through the roof, rather than out the side. This allows our spring-loaded duct dampers.

Electricians placed more light fixtures, wired more outlets, and installed my attic antenna. They aimed it right at the Madison Community Tower, which is about 5 miles away.

Plumbers installed gas lines, including the rough-in for the refrigerator water supply and the gas line to the cooktop.

I'm posting these pictures because I like wires and pipes...

From all indications, today was another busy day for the electricians and HVAC crews.  However the most visible progress for the day is the plumbing and installation of a radon mitigation system, so today's post will focus on those two items.

Plumbing (including drain water heat recovery)

Today the plumbers installed our Power-Pipe (which is explained in much greater detail on our Drain Water Heat Recovery page). The folks at Dave Jones plumbing were cooperative with us on this install, arranging the drainage so that all three bathrooms, including all showers, drain through this system.

They also installed the supply pipe and vent for the hot water heater (natural gas). The plumbing in that area is a little bit congested, and will become even moreso when the second hot water heater arrives. However, we are keeping all this stuff in a small area to maximize the space for finishing the basement.

Radon Mitigation

Radon is a radioactive gas that’s invisible and can neither be smelled nor tasted. It is produced from a natural breakdown of uranium in soil, water and rock and can contaminate the air you breathe. According to a recent National Academy of Sciences study, radon is the second leading cause of lung cancer in the U.S. today behind smoking.

A sealed sump pit was a requirement for Energy Star qualification of the home. A rough-in radon mitigation system was good for a couple points on the Green Built Home checklist. The total charge to us for the sealed pit and the passive system was $500.

As it turned out, Focus on Energy offers a $250 rebate for an "active sub-slab and moisture management and ventilation system" -- and the cost to us to add a fan was about $200. Thus, the option to add the fan was cash-flow positive, so we got the complete solution up front.

As for the attic fan, we located it right next to the attic access, over the master bedroom closet. The fan is supposed to be virtually silent, but over the closet and toilet room, that doesn't matter as much. The average fan is also expected to last 7-10 years, so this location is much more convenient for servicing when the time comes.

This morning I met with Matt and Modern Heating & Cooling at the house. We discussed placement of the geothermal heat pump, ducts, and thermostats. I also picked up the housings for our LED recessed lighting at Madison Lighting, and brought those out for the electrician. Tonight, under the light of the setting sun and the rising full moon, I came back for picture time.

The "punch list" contained many of the issues that were discussed yesterday with Laura during our Energy Star visit.

I also took a video this morning as Madison Gas & Electric was digging the trench for the gas line: