Author Archives: mrettig

“Built to Code”

DSC_0092Owning a home that is built to code gives you access to many mortgage options and rebate programs, and can make it easier to sell your home when the time comes. But what does it mean to say a house is “built to code”?

A house is built to code when it meets the requirements set forth in local building code. Local building departments typically adopt the International Residential Code, designed to protect the health and safety of occupants.

The IRC regulates construction of houses, duplexes and townhouse units. It covers the whole building – from structural components such as floors, walls and roofs to mechanical, plumbing and electrical systems. It addresses common and conventional construction practices – and does not cover atypical, custom construction. However, the IRC is constantly being revised to address new technologies and practices as they become more common.

City building departments typically tailor the IRC to their location. For instance, in Fairbanks, city ordinance 5834 amends the code to clarify building type definitions and add requirements for carbon monoxide detectors. It also amends the sections on snow loads, ice barriers and flood loads to apply specifically to Fairbanks.

City building officials determine whether or not a house is built to code with a 3-step process. First, the code official inspects the building plans and identifies any code deficiencies. These issues will have to be revised before a building permit is issued. If the code does not address a technology or construction practice used in the building, the code official will decide as to whether or not adjustments should be made.

Second, the house must be inspected during construction – including foundation, walls, electrical system, mechanical system, ventilation system and more. Contractors must arrange inspections during certain construction milestones.  If the code official determines the house does not meet code requirements, contractors must bring it up to code before moving on.

At the end of construction, there is a final inspection and the city issues a certificate of occupancy.  At this point, the house is considered “built to code.”

While building code technically only applies to homes inside city limits, homes in the greater borough can also be inspected to receive a certificate stating they meet code if the homeowners need a mortgage or loan.  In this case, rather than going through the city building department, builders will have to consult with the International Council of Building Officials, a group of building inspectors.

A Holistic Approach to Sustainable Northern Communities

The First Roundtable on Holistic Design at CCHRC in Fairbanks, October 2014.

The First Roundtable on Holistic Design at CCHRC in Fairbanks, October 2014.

Tens of millions of dollars are spent each year on housing and infrastructure to improve quality of life in rural Alaska – wind turbines, power houses, roads, housing, weatherization, plumbing, and much more. Meanwhile, many Alaska communities are struggling to survive in the face of energy costs, climate change, coastal erosion, lack of jobs, and other challenges.

Plenty of organizations are trying to help – state and federal agencies, regional corporations, housing authorities, tribal entities, nonprofits – each focused on an individual aspect: energy, housing, sanitation, transportation, health, local economies, culture, education. Yet rarely do we address all these pieces in a holistic approach. The evidence is everywhere: brand new $70,000 sewer lines hooked up to rotting houses; leaky homes in villages that pay $8 a gallon for heating fuel; roads built one year and dug up the next to install water pipe.

Jack Hebert with CCHRC talks about the role of energy efficient housing and indoor air quality in community development.

Jack Hebert with CCHRC talks about the role of energy efficient housing and indoor air quality in community development.

The Holistic Approach to Sustainable Northern Communities is a demonstration project that will factor in the many elements of community development. It started with two roundtable discussions this fall, where leaders from all levels of government and community planning came together and shared their successes and challenges, their needs and ideas for a more effective process. Now we are planning a pilot project in the Yukon Kuskokwim region that starts with one piece and builds a model of collaboration for all communities in Alaska.

Stay tuned for our next roundtable in Anchorage in December!

What are Vacuum Insulated Panels?

Vacuum insulated panels, or VIPs, are a relatively new product making their way into buildings in the United States.

They can be used as stud cavity insulation or as continuous exterior insulation on structures, just like other types of insulation.

As the name describes, VIPs consist of a panel with the air inside of it removed to form a vacuum. It isn’t a perfect vacuum, but the air pressure inside the VIP is considerably less than ambient pressure. The panels are airtight and resistant to water vapor absorption. They make good insulators because the lack of air almost completely eliminates conductive and convective heat transfer through the center of the panels. Typical panels are fairly small, 1 x 2 feet or 2 x 4 feet, and about 1 inch thick.

VIPs have an R-value of approximately R-25 per inch at the center of the panel and about R-20 for the whole panel (exact R-value depends on the manufacturing process and materials). The center of the panel will have a higher R-value than the edges, much like a window, as edges provide a thermal bridge for conductive heat transfer and lower the R-value of the entire panel. Even the whole-panel R-value is considerably higher than other insulations: fiberglass batts are around R-3.8 per inch, EPS is around R-4 per inch, and XPS is around R-5 per inch.

VIPs are installed on the sheathing plane of a building using adhesive. The material surrounding the VIPs in a wall is very important, because it helps protect the VIP from damage during installation. However, because the VIP is not continuous, the lower R-value surrounding insulation will bring the total wall R-value down. This is similar to what happens in a traditional stud-framed wall with fiberglass batts in the cavities — the wooden studs provide a thermal bridge for heat to escape and reduce the total wall R-value. With VIPs, even if the “studs” were made of EPS insulation, the whole wall R-value will still drop more than the fiberglass wall drops with the addition of wooden studs. It is important to consider how to provide structure for VIPs without providing too much thermal bridging.

As with any new building product, there are potential disadvantages of using VIPs that must be considered. First, VIPs must be manufactured in a factory and then shipped to the building site.

They can’t be cut or modified in the field. This means that detailed plans must be completed prior to construction and there is no flexibility in modifying them, unlike a traditional stick-framed wall.

VIPs also cost quite a bit more than other types of insulation. In addition to the more intensive manufacturing process, the panels have to be shipped to the building location.

There are currently only a few manufacturers in the United States, so this could be quite a long distance.

Finally, panels will naturally lose some vacuum over time. When they do, the R-value drops substantially. Manufacturers currently estimate the lifespan of the vacuum at 25 to 50 years. The seals must be treated carefully during the shipping and installation process to protect the vacuum. And putting a nail through a VIP damages the R-value of the panel much more than with other types of insulation. Losing the panel vacuum due to a hole in the panel reduces the panel’s R-value by more than half, often bringing it down to around R-6 per inch.

VIPs in Alaska

VIPs have a number of applications throughout the world, including refrigeration equipment, vending machines, shipping containers and construction. A few companies are manufacturing them in the United States, including Nanopore and Dow Corning. The new engineering building at the University of Alaska Fairbanks will use Dow Corning VIPs in a test wall system, which consist of fumed silica (basically glass powder) wrapped in a layer of plastic and aluminum. In effect, the plan is to replace some EPS foam in the wall system with a small vacuum panel. UAF researchers are planning to measure the installed R-value of the panel to study its appropriateness for buildings in our climate.

Moisture Performance of Cellulose Insulation

Blowing dense-pack cellulose insulation into the test walls.

Blowing dense-pack cellulose insulation into the test walls.

Building envelopes have a hard job in Interior Alaska—keeping us warm, dry and healthy at 40-below. CCHRC tests a variety of building designs and products to see how they can be applied in this environment. We recently studied the moisture performance of cellulose insulation to see how it compared to other common types, like fiberglass and rigid foam, and how it performed in a super-insulated house.

First, let’s look at a conventional wood-framed wall with 2×6 or 2×4 studs and an interior vapor barrier. This system has historically worked in the Interior because the vapor barrier limits the moisture allowed into the walls and moisture that does sneak in remains frozen through most of the winter. During the spring, the walls thaw and dry to the outside.

But when you add exterior foam insulation to a house, a common retrofit technique to save energy, the walls can no longer dry to the outside. Is this good or bad for the wall? Depends on how much you add. If you add enough exterior insulation (for example, six inches of EPS foam for a 2×4 wall) the sheathing and framing will stay warm enough to avoid condensation, improving your overall moisture control. If you don’t add enough, however, you move your wall sheathing into the danger zone—above freezing and very humid.

We’ve learned from earlier studies how to use fiberglass and EPS and XPS foam in various wall systems to improve energy efficiency while avoiding moisture problems (See This latest study looked at how cellulose performed in different wall scenarios over an 18-month period. These were not standard walls—they intentionally lacked a vapor barrier because we wanted to force moisture into the walls.

Cellulose insulation is made primarily of recycled paper. As a local, rather inexpensive product, it has recently become more popular in building in Interior Alaska. “Dense-pack” cellulose is blown into a wall to a density of 3.2 pounds force per cubic foot, which is designed to prevent the insulation from settling over time. Dense-pack cellulose has an R-value (or insulation value) of 3.7 per inch—slightly higher than fiberglass batts and slightly lower than EPS foam.

Our study shows that cellulose can handle moisture better than fiberglass or EPS insulation when used properly. The test wall that used cellulose as both interior and exterior insulation maintained lower humidity levels (and was less likely to condense or grow mold) than the test wall that used interior fiberglass and exterior foam.

That can be partly attributed to material properties of cellulose. Dense-pack cellulose is actually less permeable to air flow than fiberglass batts. So when used as interior insulation, it reduces the amount of moisture that migrates into the stud cavity.

Cellulose also has the ability to absorb and release water vapor, allowing it to moderate moisture levels within a wall and prevent the large spikes in relative humidity that cause moisture damage.

It’s also more permeable to water vapor than EPS or XPS.  The test wall with exterior cellulose had lower humidity levels than the wall with exterior foam, because it allows faster drying to the outside.

Based on this study, dense-pack cellulose can provide a good option for exterior insulation beyond rigid foam board. In future studies we plan to look at the minimum amount of exterior cellulose needed to keep the sheathing warm and dry.

What is Timber Frame Construction

Photo Courtesy Dave Miller

Photo Courtesy Dave Miller

Timber frame homes are characterized by large structural wooden beams visible throughout the interior. Timber-frame construction techniques have been in use for hundreds of years throughout the world, initially brought to North America by European settlers.

The skilled craft of timber framing remained common practice until the early 19th century, at which point both milling and construction methods shifted to machines and mass production. Advances in technology, such as large powered circular saws, enabled mills to quickly produce large quantities of smaller dimensional lumber, which could be more easily transported. In turn, mass produced smaller framing members made it possible to erect a home with only a small team of builders using “stick frame” construction techniques that remain relatively unchanged to this day.

While timber frame construction is still in use, it has evolved from the purely practical construction technique that it once was. Originally, timber framing was primarily structural, however in today’s homes, timber frame construction is also used to showcase the aesthetics of the timber frame substructure, since it remains exposed towards the home’s interior.

Many different tree species can be used for a timber frame, including Douglas fir, Sitka spruce, Eastern white pine, red cedar, oak and Interior Alaska white spruce. The trees are handcrafted or milled into large beams.

In the United States, there are several suppliers who cut custom beams according to a computer-aided design plan sent to them by a builder.

At the building site, the beams are assembled into a structural frame that is fastened together with a combination of carefully fitted interlocking wood joints and wooden pegs and splines. In a traditional timber frame, metal connectors of any kind are seldom used. A completed frame will contain combinations of dozens of types of joinery that make it unique.

For instance, some substructures are built like wooden furniture, where the connecting beams use mortise and tenon joinery, a process through which two beams are cut so that one has a square or rectangle opening (the mortise) into which the other beam (the tenon) fits exactly.

Usually, joints of this type are held together with exposed wedges or pegs and have the additional benefit of great strength. (A similar construction technique, post-and-beam, uses metal braces and bolts to connect beams.)

After the timber frame substructure is erected, it is enclosed, often using structurally insulated panels (SIPS), to complete the home’s envelope. Most timber frames homes have open interior designs to showcase their exposed architecture. Plus, interior walls are not needed for structural purposes.

Timber frame homes come in all sizes, from small cabins to expansive homes. While timber frame construction tends to cost more than traditional stick-frame construction, the extra planning, materials, and labor results in a truly unique and durable home.

Today, timber frame construction fills both a practical and artistic role in the building community by crafting a home that is both a shelter and a work of art.

What is an Arc Fault Circuit Interrupter?

An arc fault circuit interrupter, or AFCI, is designed to detect dangerous electrical arcs and disconnect power to the circuit before a fire starts.  They contain current and temperature sensors as well as a microprocessor that can distinguish arc faults caused by unintentional electrical hazards.

An arc fault is the unintentional flow of electricity between two separate wires.  This electrical discharge can create enough heat to further break down electrical insulation and start a fire, especially if nearby objects are flammable, such as a wooden floor, wall or piece of furniture.  For instance, an arcing fault might occur in a power cord that has been damaged (for example, crushed beneath a piece of furniture).  The damaged insulation could enable electricity to jump across to a neighboring wire within the cord and build up enough heat to start a fire. Arcing faults can also occur in power cords where the insulation has cracked due to age – or in electrical wires inside a wall that have been accidentally pierced by a nail.

According to the Electric Safety Foundation International, arcing faults are responsible for 30,000 home fires each year in the United States. These types of fires can be prevented by installing AFCIs. In new homes, AFCIs are now required in the living room, bedrooms and dining room.

There are three types of AFCIs.  The most common, a branch AFCI, replaces standard circuit breakers in your home’s service panel. Branch AFCIs can detect an arc-fault in the circuit from the panel to the outlet and thus will shut off electricity to that branch circuit. Outlet AFCIs provide arc-fault protection to devices plugged into that outlet.  Combination AFCIs are a more advanced technology that can detect additional kinds of faults, such as an arc within a single wire due to a loose connection.

Does your home have AFCIs?

You can check to see if your home has AFCIs by looking at the outlets and the circuit breakers.  An AFCI outlet and circuit breakers will be labeled as such and have a TEST button on them.  AFCIs are not to be confused with ground fault circuit interrupters (GFCIs), which also have a TEST button. GFCIs are another type of electrical safety device that detect current imbalances caused by a current leak, which can occur in the case of electric shock. They are required in bathrooms and kitchens and are often installed in other locations with water exposure, because moisture increases the risk of electric shock.

GFCIs protect people from electrical shock and AFCIs protect structures from fires.  If you have AFCIs installed, they can be tested by pushing the TEST button. If the circuit trips, then the AFCI is working.  To reset the AFCI, first turn the breaker to the OFF position. Then you will need to flip the breaker back to ON.  If the circuit does not trip, the AFCI should be replaced.  AFCIs can be installed by a licensed electrician and typically cost less than $50.

For more information about AFCIs and other electrical safety devices, visit the Electrical Safety Foundation International’s .

What are indoor “pollutants”?

Ventilation receives more attention these days because houses are more airtight and better insulated than ever before.  While this saves on heating costs, it also means that passive air leakage through the building envelope will not provide sufficient ventilation. Mechanical ventilation systems, such as exhaust fans or HRVs, are needed to flush out pollutants and provide fresh air to occupants.

Pollutants can be introduced into a home in many ways – people breathe out carbon dioxide, heating appliances can produce carbon monoxide, radon can leak in through the foundation, and dust can blow in through a door or window.  Pollutants are also produced in kitchens, one reason for installing range hoods above stoves.

What pollutants are produced in kitchens?

Cooking is a source of both moisture and odors.  Both of these are good in small doses – water vapor helps to maintain higher indoor humidity during dry winters and smells can entice the family to a common place.  Excess humidity, however, is conducive to mold growth.

Gas burners release gases directly into a home, and they can reach harmful levels if not exhausted.  Nitrogen dioxide, which can cause respiratory problems, is produced as a result of gas combustion. So is carbon monoxide, a colorless, odorless gas that reduces oxygen delivery to organs and can be very harmful—and even fatal—to humans. If you have a gas burner, it’s a good idea to have a carbon monoxide detector in your kitchen, in addition to ventilation.

All cooking appliances also produce small airborne particles, including particles under 2.5 micrometers in diameter that can enter lungs and cause respiratory problems. An extreme example of this (and one you can smell) is when you turn on a heating appliance that has been off for a long time, such as when you use a toaster that hasn’t been used in months. Finally, certain cooking methods and foods can result in other harmful pollutants. The most common is acrolein, which many people will recognize as the acrid smell of burnt fats, such as cooking oil.

What is effective kitchen ventilation?

First, effective kitchen ventilation will depend on the amount and type of cooking that you do.  Boiling water for mac and cheese every once in awhile will not produce as many pollutants as pan frying steaks during on a Saturday night in a restaurant.  Of course, most homes fall between these two extremes. Consider your cooking habits when choosing a ventilation strategy.

Range hoods are your best option for kitchen ventilation and come as stand-alone systems or can be integrated into other kitchen appliances, such as microwaves. They should be turned on every time you cook. Range hoods can vary in performance, so it is important to ensure that your system provides sufficient ventilation for the type and volume cooking that you do. Also, range hoods must actually exhaust air outside a home rather than just circulate air through a grease trap. Ideally the range hood should also extend over all burners of the stove. In the summer, opening a window can also help with ventilation.

Whole house ventilation systems such as HRVs also help provide adequate ventilation for your house while cooking, as it’s common for range hoods to capture only a fraction of the pollutants released.  One option is to use a boost mode for the HRV while cooking.  If you do use an HRV for kitchen ventilation, be careful that the HRV is not in recirculation mode (which circulates air through a home but does not exhaust air outside and bring in fresh air) during cooking times.

How much can I save with a programmable thermostat?

Programmable thermostats are an easy way to potentially save hundreds of dollars a year on heating.

Programmable thermostats are an easy way to potentially save hundreds of dollars a year on heating.

Many of us use programmable thermostats to reduce the indoor temperature when we’re sleeping or away at work. These devices are relatively inexpensive to install and can save energy by automatically reducing the amount of heat provided to the home when you’re away and then returning the house to a comfortable temperature when you return.

The amount of energy and money saved by a programmable thermostat depends on a lot of factors: insulation levels, efficiency of heating equipment, and the typical indoor temperature all can affect potential savings. CCHRC modeled a typical Fairbanks home to estimate the savings from installing and properly setting a programmable thermostat. The modeled home is 1,840 square feet, has insulation levels typical of a home built in the 80s and 90s and uses an 80% efficiency oil-fired boiler. The thermostat is typically set at 70 degrees.

Over the course of a year, 16 gallons of fuel oil were saved for every one degree that the temperature was set back in this modeled home. This assumes that the temperature was reduced for 12 hours a day when the occupants were away or asleep. So, for example, a homeowner who programmed their thermostat to turn the heat down from 70 to 60 degrees for 12 hours while they were sleeping or away is estimated to save approximately 160 gallons of fuel oil over the course of a year–around $650 at today’s prices.

How can such a small temperature change save so much?  The key is that it happens every day throughout the year.  As a comparison, over the course of a year, the average annual temperature in Fairbanks is only about 10 degrees cooler than the average annual temperature in Anchorage– a few degrees each day can make a big difference.

Not everyone will see such large savings.  People with more energy efficient homes use less fuel, and thus stand to save less money from using a thermostat.  It’s also important to properly program the thermostat–recent research has shown that while people can save significant amounts of energy with programmable thermostats, many people see no savings because they haven’t properly programmed the devices.

For the average home in Fairbanks, programmable thermostats are a simple, cost-effective, painless way to lower your energy bills.

What are Structural Insulated Panels and considerations for Alaska

SIPsStructural Insulated Panels, or SIPs, are prefabricated building panels that combine structural elements, insulation, and sheathing in one product. SIPs can be used for the walls, roof and floor of a building in place of more traditional construction methods, such as stick-framing. A SIP typically consists of a foam insulation core with a structural sheathing panel bonded to both faces. Sheathing panels are usually made of industry standard OSB or plywood.

Building with SIPs


Constructing a home from SIPs begins at the design phase: builders must work with the SIP manufacturer since the panels are specific to the design. Once the plans are finalized, the SIPs are made and shipped to the job site. The panels are labeled so builders know exactly where each panel goes in the building.

As they are erected, the panels must be joined together according to manufacturer specifications. For instance, many panels are joined with splines that are secured with screws. When the structural connections between panels are being made, workers must take care to seal the joint between the panels to ensure it remains airtight. Air sealing the panel joints can be accomplished using sealing agents such as caulk, adhesive, mastic, spray foam or tape. A tight seal is also necessary in order to prevent moisture from entering the panel, which can lead to structural deterioration of the panel components over time. Some building inspectors may require a 6mil polyethylene sheeting vapor retarder be installed on the interior side (warm side) of the SIPs once the panel construction is completed.


Electrical outlets and wiring are usually installed into recesses and holes pre-cut into the panels, both on the interior and the exterior as needed. Any special considerations for running electrical systems or other mechanical penetrations through the SIPs should be addressed with the manufacturer during the design phase.

Benefits and Concerns

There are several potential benefits to building with SIPs. For one, the absence of an air permeable wall cavity prevents convective heat losses from occurring within the panels. Large panels will have fewer framing members than a stick-framed wall, which reduces heat losses due to thermal bridging. With a trained crew, SIP buildings can be erected quickly, a big advantage in climates with short building seasons. Properly constructed, a SIP panel home can realize a high level of air tightness and energy efficiency.

On the other hand, builders must take extra care to ensure proper assembly and sealing to prevent any problems due to moisture infiltration and air leakage. Builders also do not have much flexibility in on-site design changes, since panels come pre-cut. An experienced builder who can work through a home design with the manufacturer and who doesn’t cut corners with sealing panel joints is a necessity.

SIPs can be either cost-effective or cost-prohibitive depending on the situation. The design services and shipping costs may drive the price of SIPs above that of conventional framing materials. However, this can pay off in reduced labor costs if a trained crew erects a building quickly, or if several buildings of the same design are being erected.

CCHRC Creating List of Preferred Energy Auditors for Fairbanks Nonprofit Retrofit Pilot

CCHRC is pleased to announce that it is creating a list of preferred energy auditors to perform audits as part of the Fairbanks Nonprofit Retrofit Pilot project.  Qualifying energy auditors in Alaska are invited to apply at

The pilot project connects the nonprofit community with financing to enable energy efficiency retrofits. CCHRC will evaluate the process and outcomes of this model to better understand several factors: the extent to which financing can replace grant funding for energy efficiency audits, the extent to which program delivery is enhanced through reduced energy costs, and the extent to which partnerships with the nonprofit sector are necessary to advance energy efficiency retrofits from audit through construction.