Friday, May 15, 2009

Solar Power!

We are very excited about the prospect of installing solar power on our house, something we were not sure we could afford. Through a new program that has just arrived in Massachusetts, we have signed up to have 4 kilowatts of solar panels installed on our roofs through what is called a power purchase agreement. The gist is that we pay very little up front ($1,000) and then sign a long-term power agreement with Sun Run Power, which charges us $0.14 per kilowatt hour for the next 18 years, which is about $.06 less than what we pay now. Even if electricity rates do not go up, we pay for the project in 6 years and then save money after that. If electricity rates go up, we save even more. And we expect that the 4200 kwh produced by these panels should provide more than half, maybe 2/3 of all our energy needs for the entire year! At least that's what we're hoping.

Alteris Solar was the local installer arm of this program and they came out a couple of weeks ago to do a roof analysis. Even though we have east and west facing roofs, their analysis showed that because our roofs are relatively flat, and we have very little shading, our production would actually be pretty good. We're very excited, given that our house will be all electric.

Exterior Foam Installed!

Scott and crew have made great progress in installing the 4 inches of exterior rigid poly-iso foam (from Iko Enerfoil) around the entire house. They have also attached wooden strapping, using 8 inch timberlock screws to ensure that the foam stays up and to provide a base to which the siding will be attached.

The foam was installed in two layers, staggered so the seams did not overlap, and then taped along the seams. The result should be an efficient air barrier and another R24 of insulation.

Apparently, the strapping was the most difficult and time consuming portion of the work, given that they had to pre-drill 8 inch holes into the studs and screw each screw individually.

The strapping also helps to provide a drainage plain behind the siding to allow water to drain away from the house. I have learned that this is a good way to do siding even if there is no added insulation.

Wednesday, April 15, 2009

Exterior Foam Started!

Finally, the exterior foam work has begun. Rigid closed cell foil faced foam (called Iko Enerfoil) arrived the 1st week of April and Scott's crew has moved quickly to begin the process of attaching the foam to the house.

Virtually all the shingles have been stripped and 2 layers of foam have been installed, with the seams taped and each layer staggered to ensure a more effective air barrier.

Remaining is some of the detailed air sealing work that will need to fill in all the gaps by the windows, doors, at the bottom and top of the foam. Scott Sorensen (contractor) and Olaf Vollertsent (architect) have had many conversations about where to spray foam, how to seal the foam at the corners, what screws to use to attach the foam and then the strapping, etc. etc. Complicated stuff but necessary.

More to follow on some of those details, but the photos here show some of the early foam work.

Construction Continues

Construction has moved quickly so that by late March/early April,, virtually all of the exterior framing and construction has been completed.
The top front dormer was completely demolished and then rebuilt with a new roof and entirely new framing and sheathing (see photos).
It's starting to look like it's supposed to, and even thought our exterior footprint is only slightly larger than our original house, it seems much larger both inside and out.

Scott and his crew work incredibly quickly, rebuilding the dormer in just a week. The site is kept incredibly clean at the end of each day and the work seems solid. We're especially pleased with some of the attention to details that have replicated the period roof and eaves.
The windows on the top dormer are especially large, primarily because of code issues and required opening height for emergency egress.

Our almost 4 year old son continues to call this our green house, and although I'd like to believe he understands what we are doing, I think it's just because the sheating is green. :)

Saturday, March 21, 2009

Material Recycling Report

Thought we'd post the results of our first Construction material recycling report from E.L. Harvey. For January and February the results are:

7.97 tons of materials generated

1.20 tons of concrete diverted

5.58 tons of wood diverted

6.77 tons of material diverted

85% recycling rate

Although we are astounded at the amount of material being generated from this relatively modest project, we are excited by the efforts and reporting of E.L. Harvey, which, apparently, is one of the premier C&D recycling companies in the area. And it's great to know the results, which seems to be a unique feature from this company. And, it costs no more than normal C&D management companies. We plan to get more information about where the materials being diverted actually go.

Tuesday, March 17, 2009

Totally forgot to mention that a week before work began, we had a blower door test conducted by Byggmeister (, a local newton green remodeling company, as well as a HERS rating analysis. For those who know about these things, the results were:

1. 2400 CFM at 50 pascals
2. A HERS rating of 111

I'm told that the 2400 CFM is a moderate leakage rate, not horrible but not great, and that the 111 score is better than many older New England homes, which often get scores of 130 or above. A home built to the current code would receive a score of 100. We'll say it here: our goal is to get our CFM down to 1,000 and our HERS score to 60. Not sure if we'll get there but we'll see.

Tuesday, March 3, 2009

We still have not yet begun the super insulation part of the project, but the house is starting to take shape inside and out. The addition is framed, using a Zip sheathing from Huber, which resists the elements better than traditional plywood sheathing and is slightly cheaper!
We plan to soon remove all the insulation from the attic (which has multiple layers of mixed types) but the weather has made things move a bit more slowly.

Several key decisions have been made, such as triple pane low-e glass fiberglass windows from Fibertec ( and we're actually converting to an all electric house, including the water heater and range. This is not necessarily our first choice, but there are several reasons, some of which are more compelling than others:
1. A house that is so tight is much safer without any combustion inside the house
2. The price of electricity can only go as high as the cost of solar, while who knows what will happen with gas prices.
3. We reduce our utility billing and payment effort to just one per month.
4. We eliminate the minimum charges associated with just having gas service.
5. Since our HVAC system, which will be the highest cost energy user in the house, will be electric, it made sense to go all electric.
6. Our water usage is pretty minimal (was about 10-14 therms per month) so even with electric the cost shouldn't be that high.

We will see if we made the right decision, but one option is to buy green electricity until we install renewables so as to reduce our carbon footprint.

We're also using E.L. Harvy to recycling our C&D waste and expect our first report from them in mid-March.
Several windows have been framed - note the extra inches on the window frame in preparation for the 4 inches of insulation on the exterior. In talking to our contractor, this is clearly a new approach to window framing but doesn't really seem all that complicated and provides the structural strength needed for the heavier triple pane windows.
We expect the exterior insulation to start once the front, 2nd floor dormer has been rebuilt. Will post more pictures then.