Sunday, March 18, 2012

Blower Door Testing

As Maine home builders strive to enhance energy efficiency in new home construction, blower door testing is being utilized as a valuable tool to measure how effective we are at air sealing to eliminate unconditioned air from entering the building envelope

A simple concept: with all windows, doors, and other pathways for outside air to enter closed, the blower door temporarily seals itself into an exterior door opening, blows air out of the house at a controlled rate, and measures how much (or how little) replacement air is entering the house


Often, a test may be conducted before the installation of insulation so that air leaks can be identified and corrected while there is access to areas that will be inaccessible after insulation has been installed

An additional test may be conducted after insulation and drywall have been installed to measure the final results

Some municipalities in Maine are now requiring blower door testing as a condition to receive a certificate of occupancy

While test results can vary widely depending upon the goals and construction details of the project, blower door testing can benefit all new home construction in Maine

Saturday, December 10, 2011

Geo-Thermal heating in Maine

We are currently working on a project that is utilizing a ground sourced Geo-Thermal Heat Pump HVAC system.
I am a big fan of these systems as they are unmatched for efficiency of operation. Geo systems are about 400% efficient as compared to the best LP systems which are about 95% efficient. In other words, for every dollar of energy purchased to operate the system (electricity for a Geo system) a Geo-Thermal system delivers four dollars worth of heat (the LP system delivers .95 cents worth of heat for every dollar of LP purchased)!


This system was designed and installed by Elco Geo-Thermal Heating of Bangor ME.
It is an "Open Loop" system which utilizes the existing domestic supply well for its heat exchange source. Simply, water from the well is pumped to the heat pump, heat is extracted from the water, and then it is returned to the well.




The system delivers heat and air-conditioning via a ducted forced air delivery.
As an added benefit, whenever the system is operating it also pre-heats domestic supply water as a free by-product which is then held in a storage tank until required which further reduces energy costs.

We have also added a Heat Recovery Ventilation (HRV) system which works in concert with the HVAC system to provide a continuous fresh air exchange into the building envelope while capturing much of the heat from the exhaust air being removed from the house.




These systems do cost more than typical Oil or LP boiler/furnace systems, however they currently enjoy a 30% Federal Tax Credit (through 2016) which makes the installed price very competitive and the return on investment time relatively short.

I am a big fan of these systems and we are specifying them in several upcoming projects, including our own home!

Monday, August 15, 2011

Energy efficient construction

No matter what house style, no matter what budget, energy efficient building techniques should be utilized to enhance ongoing home energy performance.
The following photographs of a current project in New Gloucester Maine highlight a few details that will have a dramatic positive effect regarding how comfortable this house will be, as well as less expensive to heat.

Intersecting wall framing techniques that allow full insulation to be installed in the outside wall cavity which eliminates an area of potential thermal transfer from conditioned to unconditioned space


Insulated window and door header assemblies with continuous rigid foam insulation


Wall corner construction that allows our blown in insulation to fully insulate this often neglected area


Even though we utilize foam sill seal gasket between the sill plate and foundation wall,
we also caulk this seam with silicon caulk


We will foam seal all sheathing panel edges as well as both sides of any wall stud where two panels meet and at the top and bottom plate

It only takes advanced planning, a little extra time and a few cans of DOW Pro foam to make a big difference.

Tuesday, May 24, 2011

Build new houses tight, tight, tight!

I sometimes hear people say things like "new houses today are being built too tight".

I might share this opinion if I were a home heating fuel salesman, but as a Maine home builder with a focus on saving my customers money through energy efficient construction, I say that it is better to understand building science, specifically moisture management, and build new homes as tight as you are able.

Years ago, fuel costs were low, and moisture management not well understood. Houses that leaked air were not much of a concern. They would get wet, but with an abundance of air moving through the walls would dry avoiding moisture damaged assemblies.

With rising fuel costs houses had to become better insulated and tighter, and fortunately within the past decade or so, building science case studies have shown new home builders the way to build structures that are not only tight, but also properly manage bulk moisture from external sources and moisture vapor from internal sources.

Today's home builders are fortunate to have the availability of a wide variety of excellent building products as well as the educational resources to build new homes that are both energy efficient and sustainable.

Products such as "Greenguard Raindrop house wrap" which facilitates a drainage plane between exterior cladding and wall sheathing, "Advantech" brand roof and wall sheathing which is highly resistant to moisture damage, "DOW" "SIS Structural Insulated Sheathing", "Styrofoam" extruded insulation panels, and "Thermax" insulation panels, "DOW" "Weathermate" construction tape and "DOW" "Great Stuff Pro" expanding foam insulation just to name a few.


New home builders that combine tight construction methods with advanced insulation materials and follow proper moisture management techniques will have happy customers enjoying comfortable, sustainable homes with reduced utility costs.

Wednesday, April 13, 2011

Fiber-Cement Siding: Worth considering for your new home

If you are interested in a durable, low maintenance, clean finished look for your new home construction project, Fiber-Cement siding is an excellent choice to consider.

Available in horizontal lap, vertical panel, shakes, and trim, it is a green product known for durability and beauty.

A wide variety of factory applied finish colors are available which will remain beautiful long beyond that of a typical site applied finish product.


We have utilized CertainTeed "WEATHERBOARDS" horizontal lap siding on a recent project and have specified it again for several upcoming projects as well. In addition to all of the previously stated benefits, "Weatherboards" has an industry leading realistic wood grain appearance as well.



Proper installation techniques are critical when utilizing fiber-cement siding. A drainage plane should be incorporated into the wall system to assure that moisture can not be absorbed into the back side of the siding, and industry best practice techniques should be followed for flashing, sealing, and bulk moisture management.

As an added benefit, Fiber-Cement costs compare favorably to other available siding choices.

I look forward to exploring with you how Fiber-Cement siding could be a good consideration for your new home project.

Tuesday, March 22, 2011

Energy Efficient Wall Construction

There are many choices to consider when designing wall assemblies that will be energy efficient and provide homeowners with a comfortable home that is economical to heat.

But which is the best balance of performance and cost to build?

We have been utilizing a method that combines advanced framing techniques, insulated sheathing, diligent wall sealing, and high performance blown in insulation to achieve these goals, and are happy to see that in a Building Science comparison of high R-value wall assemblies, this method scored quite favorably.


The Building Science study can be viewed here:
Building Science.com/high-r-value-wall-assemblies


Additional details and construction photographs can be viewed here:
The wall system, balancing efficiency and cost.



We look forward to exploring with you how these construction methods could be the best choice for your new home construction project.

























Tuesday, March 1, 2011

What does "Green" mean to you?



"Good for the environment". "Energy efficient". "Healthy".




These often spoken descriptions for "Green" construction are all applicable.




But what does "Green" really mean to you?




And which elements of green construction are important to you to incorporate into your next home?





As a new home builder in Maine, here is my "Green Construction" check list:





"Sustainable" To utilize materials and methods which ensure durability. Construction designed to last and require less maintenance. Using best industry practices learned from building science case studies(such as proper bulk moisture management techniques including drainage planes) in the structure.






"Efficient" To build beyond code minimums regarding insulation requirements. To properly install insulation following Energy Star thermal bypass guidelines. To utilize construction practices which minimize air infiltration (extensive wall sealing) and thermal bridging (insulated sheathing and advanced framing techniques). Making product selections which optimize ongoing energy efficiency (Energy Star rated appliances and lighting).






"Healthy" Utilize materials which eliminate or minimize VOC (Volatile Organic Compounds) within building enclosures to assure a healthy living environment for the occupants (Low VOC paints and Formaldehyde free plywood, sheathing, and insulation products).


Incorporate Radon resistant construction and venting techniques.


Ensure proper moisture management and ventilation practices to prevent mildew and mold growth (appropriate vapor barrier/retarders utilized).





"Environmentally Responsible" Utilize sustainable materials and products featuring recycled content (such as fiber cement siding). Use locally produced materials whenever possible (such as framing lumber that is grown/produced in Maine from forests managed for sustainability). Reduce job site waste and extensively recycle.





"Cost effective" Help homeowners to make informed product selections which best balance performance and their budget.



I look forward to hearing exactly what "Green" means to you and discussing how we can assist you to incorporate those attributes into your future home.