OUR PREDICAMENT

Our North American way of life has been created and is dependent upon cheap fossil fuels, in particular, oil. As predicted by M. King Hubbert, we have now reached or will soon reach “peak oil” - the point in time when the maximum rate of global petroleum extraction is reached, after which the rate of production enters terminal decline. The rush to “peak oil” will increase as world demand increases. The potential ramifications of “peak oil” will dramatically change the global economy and our way of life - transportation, agriculture, habitation and industry.

Concurrent with “peak oil” is the dramatic effect that burning fossil fuels - oil, coal, propane and natural gas - is having on the global climate. Human activity is raising the overall temperature of the planet with undeniable effects. Living in Canada, the signs of global climate change are obvious in the reduction of arctic sea ice, increasing melt of the Greenland ice sheet, increased release of methane from the permafrost, and warmer winters as temperature rise is greater than at the equator.

As population increases, the amount of productive farm land decreases due to urban expansion and fertility depletion. The planet offers a finite amount of resources to sustain current human activity. Finite limits have not yet been met only because of the economic disparity between nations. Wealthier nations are increasingly consuming larger amounts of resources while poorer nations live on meager and diminishing resources. The resources of the planet are not adequate to allow all nations on the planet to consume resources at the current rate of the most developed nations. Human “sustainability” has already been surpassed, yet we still talk of the need for continued growth.

The economies of the western countries - both Europe and North America - have experienced significant instability beginning with the 2008 United States housing bubble implosion (how far behind is a housing bubble in Canada?) and now the Euro crisis in Europe. Governments have shown an inability or unwillingness to confront the imperatives of peak oil, global warming (Europe doing better here), increased exploitation of natural resources, and inequality between nations.

As individuals, we may not be able to significantly impact the world on the macro level, but we do have the ability to affect our impact on the planet within our local communities, neighborhoods and homes. In order to survive as a species, we must live our lives in harmony with the natural parameters of planet Earth.

ROSS CHAPIN & MARIANNE CUSATO

Christmas has come and gone and its time to continue discussing people that have a profound influence on my thoughts.

Ross Chapin is an architect that has developed some fantastic designs of homes and cottages that he is more than wiling to share. I must admit that I envy his ability to design spaces with a true eye to detail. His homes provide a warmth and earthiness that is immediately appealing. Ross has gone one step further and written a fantastic book "Pocket Neighborhoods - Creating Small Scale Community in a Large Scale World". This book illustrates where I would like to go with my blog in the future. We all to often focus on "a building" or "the building", but avoid the context in which it will exist. His work offers a vision of how people can live in a community that fosters social interaction. This book is a must for anyone pursuing studies in architecture or anyone developing a more sustainable way of living.

Marianne Cusato is an architect that is best known for her Katrina Cottage, a housing type resulting from the devastation on New Orleans by hurricane Katrina. The Katrina Cottage concept came out of the New Urban Guild and propelled Marianne into national recognition. Once again, I am inspired by the simplicity and traditional character of her designs. Katrina cottages have been built to replace homes lost in the hurricane as well as incorporated into pocket neighborhoods. Katrina Cottages have even been sold as kits by Lowe's Hardware similar to the kits for Sears Homes.

What's most important about the work of Ross Chapin and Marianne Cusato (as well as others) is their willingness to openly share their work. If we are to transition into more sustainable communities, it will be imperative that we all openly share our knowledge. This is not the time to hoard information and ideas for personal pride or monetary gain. Food, clothing and shelter are too basic to become the domain of a few. As design professionals, we have an obligation to discuss and provide our musings with society at large.

I invite all to share in this ongoing adventure of discovery.

THOUGHTS ON SUPER INSULATED DESIGN

I just noted that I have not added any comments to this blog since April 2010. This has not been due to lack of interest or ideas. I have simply been meeting new folks and investigating new directions. Super insulation concepts are still the way to go when building a home in my climate - the Canadian Maritimes - or any other cold weather climate. The long term energy savings are real. Building codes are being upgraded (too slowly) to reflect the need for more insulation, more air-tightness, and controlled ventilation. Besides the detailing and dialog provided in past postings focusing on double stud wall construction, I have been looking at other techniques and materials (ICF, vertical truss joists, straw bale, etc.). I have found the Green Building Advisor as a valuable resource for information and discussions - in particular the Musings of an Energy Nerd blog.

While there is much to be learned in the ongoing development of super insulated design and construction, my energy is also focused on the context of the home within the larger environment. While I am always open to any questions or comments you can share, my upcoming posts will try to lead the readers to issues and sites that discuss energy efficient housing in a broader context that responds to cultural transitions we are currently experiencing.

MAISONS SCOUDOUC HOUSES

MAISON SCOUDOUC HOUSE PLAN "A"

The Maison Scoudouc House Plan "A" is designed as a small 512 sq.ft. mini-home for a single person. This size is in line with the recommendation of 500 sq.ft. per person for the size for a basic superinsulated house. A single person needs much less enclosure of spaces. In this basic house the bathroom is the only interior room with a door. The home has a basic galley kitchen and open living room. Rather than having a bedroom, this design has a sleeping alcove with adjacent closets for clothing and drawers under the bed.

The super insulated construction techniques include ICF crawl space foundation, double exterior stud walls (R45), triple glazed casement windows sized for 16" o.c. stud spacing, and raised heel roof trusses (R60). See link to Construction Details for more information on materials and detailing.

MAISON SCOUDOUC HOUSE PLAN "B"

The Maison Scoudouc House Plan "B" design is the same small 512 sq.ft. mini-home for a single person, but with a 256 sq.ft. covered porch. The porch could also be enclosed as a heat sink during cold months and an expansion of living space during warm months. The floor plan is the same as the Plan "A" with the same features.

The superinsulated construction techniques include ICF crawl space foundation, double exterior stud walls (R45), triple glazed casement windows sized for 16" o.c. stud spacing, and raised heel roof trusses (R60). See link to Construction Details for more information on materials and detailing.

MAISON SCOUDOUC HOUSE PLAN "C"

The Maison Scoudouc House Plan "C" is designed as a small 624 sq.ft. one-bedroom home or retirement cottage for a single person or couple. The 144 sq.ft. covered porch is accessible from both the living room and the bedroom. In this basic house the bathroom is the only interior room with a door, but a door could be also be added at the bedroom for privacy. The plan contains a combination living / dining room with an L-shape kitchen, bedroom and full bath.

The superinsulated construction techniques include ICF crawl space foundation, double exterior stud walls (R45), triple glazed casement windows sized for 16" o.c. stud spacing, and raised heel roof trusses (R60). See link to Construction Details for more information on materials and detailing.

MAISON SCOUDOUC HOUSE PLAN "D"

The Maison Scoudouc House Plan "D" is designed as a small 688 sq.ft. one-bedroom home or retirement cottage for a single person or couple. The 176 sq.ft. covered porch is accessible from both the living room and the bedroom. In this basic house the bathroom is the only interior room with a door, but a door could be also be added at the bedroom for privacy. The plan contains a combination living / dining room with an L-shape kitchen, bedroom and full bath. In addition to the private bedroom, this design also has a sleeping alcove with adjacent storage closets and drawers to accommodate daytime napping and visitors.

The superinsulated construction techniques include ICF crawl space foundation, double exterior stud walls (R45), triple glazed casement windows sized for 16" o.c. stud spacing, and raised heel roof trusses (R60). See link to Construction Details for more information on materials and detailing.

MAISON ST. THOMAS HOUSE

Maison St. Thomas House was designed for a friend in Nova Scotia to be built into a hillside overlooking the Bay of Fundy. The concept was to build a small one bedroom house (960 sq.ft.) with both a southerly and easterly view. Originally, the house was not designed to super insulated principles, but has been modified - more insulation, triple pane windows, HRV ventilator. Materials and detailing would be similar those shown for the Maisons Cocagne and Grande-Digue Houses in earlier posts (see Archives and Construction Details in links).

The upper level of the Maison St. Thomas House is the public level of the home. the entry foyer can serve as both closet and pantry. The upper level plan is a large open space composed of the living room area and a kitchen area with a table built into the kitchen cabinetry. The wood stove would be a pellet stove with an outside combustion air source (a must in superinsulated houses) to be used for backup and/or tempered heating.

This is a similar upper level floor plan, but with an L-kitchen with separate table and chairs for dining. Wood stove would follow comments above or could be replaced with a few baseboard heaters. The projected heating load would be reduced by the super insulated features where supplemental heat demand would be low. Ground source heat pump could be overkill as the demand is so low, but a heatpump water heater may have potential for hydronic or fancoil heating.

The lower level of the Maison St. Thomas House is the private area of the home containing he bedroom and bathroom. This level would be sheltered by the earth on the west and north elevations, and open to a walkout patio or garden on the south and east elevations. The south and east patio areas of the lower level could also have a covered porch if so desired.

MAISON GRANDE-DIGUE HOUSE - Exterior Deck

The exterior decking of the Maison Grande-Digue House can be done in any of several porch decking techniques. It is critical however that the deck framing be spaced from the building to prevent rot. All structural framing members should be topped with strips of asphaltic, water resistant building paper or ice shield. Materials shown are treated materials using appropriate fasteners for the treatment used.

MAISON GRANDE-DIGUE HOUSE - Foundation

Maison Grande-Digue House is designed with double 2x4 insulated, exterior stud walls @ 24" o.c. separated by a 3-1/2 inch fully insulated space to isolate the exterior walls from thermal bridging. The outside double stud walls would be erected prior to construction and erection of the interior partition walls. The inside stud walls are designed to be load bearing while the outside stud walls are designed to carry the exterior finish. The cold side of the inside stud wall is completely covered in a 6 mil vapor barrier then sheathed with 1/2 inch CDX plywood sheathing to provide lateral bracing as well as protect the vapor barrier.

Red dashed line shows location of the 6-mil vapor barrier in the wall system. Red dots show locations where barrier is sealed with acoustical caulking.

Experience has shown that the vapor barrier can be safely installed inside the wall as long as 2/3 of the insulation is on the cold side of the barrier. Locating the vapor barrier at the cold side of the inside stud wall allows for installation of electric without penetrating the vapor barrier. The cold side of the outside stud wall is sheathed with 1/2 inch fiberboard sheathing, then covered with house wrap. The design allows for the walls to be framed and insulated on the floors and lifted in place using wall jacks. A perimeter truss with 2x4 vertical blocking in line with the 2x4 wall studs above is required to carry the loads to the foundation. Details for optional balloon framing and openings are provided in the links and will be discussed later.

The Maison Grande-Digue House foundation walls are formed using LOGIX insulated concrete forms. While not a fan of rigid insulation, insulated concrete forms do have their place in the design of a foundation. The two layers of insulation used in the ICF system provides R20 insulation for the basement plus facilitates installation of finishes both inside and outside as well as easing reinforcing placement. The concrete foundation walls also create an effective vapor barrier. Care should be taken in laying out the exterior dimensions of the building and height of basement walls to match the dimension of standard ICF components (standard LOGIX block is 16" high x 48" long x depth desired). The 12" x 24" footings are the standard architectural overkill. Adjustments are feasible based upon engineering for local soils and conditions.

As mentioned in an earlier posting, crawl space and slab-on-grade foundations are also feasible, but space must be made on upper floors for mechanical equipment. See links to construction details for additional details and foundation systems.

MAISON GRANDE-DIGUE HOUSE - Roof

Roof trusses at the main building block of Maison Grande-Digue House are parallel chord trusses to allow for 18 inches of glass fiber batt insulation (R60). The roof trusses are installed at 24 inches on center in line with wall studs below. 6-mil vapor barrier is attached to the bottom chord of the truss. Gypsum wallboard or other desired finish is attached to the truss chords on 1x4 furring strips at 16 inch on center perpendicular to the trusses.

The benefits of installing radiant barriers are still in question. If used, I would recommend attaching the radiant barrier taping all joints to the bottom chord of the trusses after installing the vapor barrier, but prior to installation of the furring strips.

Roofing material is TRACC Moderne Slate roof shingles over ice shield underlayment. This is a 50-year roofing material made locally from recycled materials capable of withstanding a 175 mph wind driven rain. This is a very important feature on the Northumberland Strait where northeasters are not uncommon. The roofing sheds snow easily so consideration must be given to sliding snow in our climate. The roofing also works well for a rainwater collection system (guttering not shown).

Maison Grande-Digue House is designed with double 2x4 insulated, exterior stud walls @ 24" o.c. separated by a 3-1/2 inch fully insulated space to isolate the exterior walls from thermal bridging. The outside double stud walls would be erected prior to construction and erection of the interior stud walls. The inside stud walls are designed to be load bearing while the outside stud walls are designed to carry the exterior finish. The cold side of the inside stud wall is completely covered in a 6 mil vapor barrier then sheathed with 1/2 inch CDX plywood sheathing to provide lateral bracing as well as protect the vapor barrier.

Red dashed line shows location of the 6-mil vapor barrier in the wall system. Red dots show locations where barrier is sealed with acoustical caulking.

Experience has shown that the vapor barrier can be safely installed inside the wall as long as 2/3 of the insulation is on the cold side of the barrier. Locating the vapor barrier at the cold side of the inside stud wall allows for installation of electric without penetrating the vapor barrier. The cold side of the outside stud wall is sheathed with 1/2 inch fiberboard sheathing, then covered with house wrap. The design allows for the walls to be framed and insulated on the floors and lifted in place using wall jacks. A perimeter truss with 2x4 vertical blocking in line with the 2x4 wall studs above and below is required to carry the loads to the foundation.

Details for optional balloon framing and openings are provided in the links and will be discussed later.

MAISON GRANDE-DIGUE HOUSE - Foundation @ Root Cellar

The foundation walls at the root cellar of the Maison Grande-Digue House are constructed using LOGIX insulated concrete forms. While not a fan of rigid insulation, insulated concrete forms do have their place in the design of a foundation and in particular a root cellar. The two layers of insulation used in the ICF system provides R20 insulation for the basement plus facilitates installation of finishes both inside and outside. The concrete foundation walls also create an effective air and vapor barrier.

Being as this is a root cellar, it is necessary for a cool, damp environment to be created. The floor of the cellar therefore is an exposed earthen surface. PVC vents are installed to control the temperature and humidity of the cellar.

The ceiling framing of the root cellar must be isolated from the moisture generated in the cellar and insulated from the cooler temperatures of the cellar. The 6-mil vapor barrier is applied to the bottom flange of the floor joist, then covered with furring strips and the cellar finish.

MAISON GRANDE-DIGUE HOUSE - Roof @ Kitchen Extension

Roof trusses at kitchen extension are raised heel trusses to allow for 18 inches of glass fiber batt or blown insulation (R60). The roof trusses are installed at 24 inches on center in line with wall studs below. 6-mil vapor barrier is attached to the bottom chord of the truss. Gypsum wallboard or other desired finish is attached to the truss chords on 1x4 furring strips at 16 inch on center perpendicular to the trusses.

The benefits of installing radiant barriers are still in question. If used, I would recommend attaching the radiant barrier taping all joints to the bottom chord of the trusses after installing the vapor barrier, but prior to installation of the furring strips.

Roofing material is TRACC Moderne Slate roof shingles over ice shield underlayment. This is a 50-year roofing material made locally from recycled materials capable of withstanding a 175 mph wind driven rain. This is a very important feature on the Northumberland Strait where northeasters are not uncommon. The roofing sheds snow easily so consideration must be given to sliding snow in our climate. The roofing also works well for a rainwater collection system (guttering not shown).

Maison Grande-Digue House is designed with double 2x4 insulated, exterior stud walls @ 24" o.c. separated by a 3-1/2 inch fully insulated space to isolate the exterior walls from thermal bridging. The outside double stud walls would be erected prior to construction and erection of the interior stud walls. The inside stud walls are designed to be load bearing while the outside stud walls are designed to carry the exterior finish. The cold side of the inside stud wall is completely covered in a 6 mil vapor barrier then sheathed with 1/2 inch CDX plywood sheathing to provide lateral bracing as well as protect the vapor barrier.

Red dashed line shows location of the 6-mil vapor barrier in the wall system. Red dots show locations where barrier is sealed with acoustical caulking.

Experience has shown that the vapor barrier can be safely installed inside the wall as long as 2/3 of the insulation is on the cold side of the barrier. Locating the vapor barrier at the cold side of the inside stud wall allows for installation of electric without penetrating the vapor barrier. The cold side of the outside stud wall is sheathed with 1/2 inch fiberboard sheathing, then covered with house wrap. The design allows for the walls to be framed and insulated on the floors and lifted in place using wall jacks.

Details for optional balloon framing and openings are provided in the links and will be discussed later.

MAISON GRANDE-DIGUE HOUSE - Second Floor

SECOND FLOOR PLAN

Maison Grande-Digue House second floor plan features two bedrooms under a sheltering roof with central full bath under a roof dormer. Attic areas would be accessible for additional storage. As mentioned previously, these homes were originally built with finishing of the second floor as an option.

The exterior gable end walls continue the double 2x4 stud walls from below. Casement windows are chosen to fit into the stud spacing to reduce framing. Final finishes and detailing to be selected by owner.

The main building component is framed with parallel chord trusses to allow for high level of insulation.

See column at left for link to architectural detailing.

MAISON GRANDE-DIGUE HOUSE - First Floor

FIRST FLOOR PLAN

Maison Grande-Digue House has a compact first floor floor plan featuring a living room, kitchen / dining space, full bath, bedroom and den. Externally, the home is shown with a wrapping deck connecting entries to living room and kitchen.

The main floor bedroom would facilitate use of the home as a young couple, family or retired couple. The den could be used as a second small bedroom, guest room, sewing room, etc.

The exterior walls are fully insulated, double 2x4 stud walls @ 24" o.c. (16" o.c. spacing may be required in high wind areas or as a preference of the owner). Triple paned casement window units are sized to fit into the stud spacing to reduce additional framing (OVE engineering). Final finishes and detailing would be decided by the owner.

More specific detailing can be found in the details links provided in the column at left.

MAISON GRANDE-DIGUE HOUSE - Basement

BASEMENT PLAN

The Maison Grande-Digue House is designed with an unfinished full basement with a root cellar. With the exception of the mechanical room and stairs, the space can be used as needed by the owners for storage, laundry or hobbies.

The basement walls are constructed using insulated concrete forms (ICF) manufactured by LOGIX.

Specific detailing can be found in the detail links located in the left column.

MAISON GRANDE-DIGUE HOUSE

The Maison Grande-Digue House is a house style that can be found in many communities throughout Canada and North America. It was built after WWII in response to housing needs for returning veterans and their families. It is included as a prototype for superinsulated housing for its simplicity and affordability. In contrast to the Cocagne House, this prototype design incorporates a sheltering roof for the second floor. Surprisingly, the floor space is about the same. When originally built, the finishing of the second floor to include bedrooms and second bath was marketed as an option. A couple could purchase an affordable home and finish the upper floor as their family grew, but revert to the main level as they aged. The homes were often constructed in developments rather than individually. Over the years these home were modified with additions or shed roofs. The homes were individualized by special architectural detailing, materials and landscaping.

The house presented in this blog is built on a full basement with two bedrooms and a bath on the second floor. It could also be built on a crawl space or slab-on-grade foundation. It could also be built as only a one story house with a trussed roof.

HEAT LOSS, HEAT GAIN & SUPERINSULATION

This will be my last post dedicated to background technical information, but is necessary to understand why a superinsulated house is superior to an insulated house. Simply put, a home gains heat and loses heat. If the home gains more heat than it loses, then we need to open the windows and/or air-condition. If the home loses more heat than it gains, then we need to shut the windows and turn on the furnace or other source of heat. The amount of heat and the length of year heat is required is referred to as the heating season. Superinsulation design will reduce the amount of heat required each day as well as shorten the heating season.

HEAT LOSS

Every house loses heat when the outside temeprature is lower than the inside temperature, always moving from warm to cold. Home heat is lost by three basic mechanisms:

1. Conduction - heat loss through materials and assemblies.

Most homes built in the past, as well as today, only incorporate the level of insulation and construction detailing that is "commonly practiced" or required by building codes. Superinsulation techniques reduce the amount of conductive heat loss by the intentional application of high levels of insulation (R40 or greater in walls / R60 in ceilings), reduction or elimination of thermal bridging in the structural framing, and installation of energy efficient doors,windows and storm doors, etc.

2. Infiltration - heat loss through air gaps.

Air-infiltration can often be the largest component of overall heat loss. Most houses built in the past, and unfortunately most today, did not fully address the need to reduce the amount of air infiltration for a multitude of reasons - "a house needs to breathe" or "don't worry, we'll put in a larger furnace" or "wood is cheap". Superinsulation techniques reduce the amount of infiltration heat loss by the design and installation of a complete, air-tight vapor barrier around the home's thermal envelope reducing air-infiltration to a minimum.

3. Ventilation - heat loss through exhausting warm air out of the house and cold intake replacement air into the house through bathroom vents, rangehoods, dryers, etc.

Superinsulation techniques reduce the potentially significant amount of ventilation heat loss by replacing traditional ventilation systems with heat recovery ventilators (HRV) that uses the warm exhaust air to preheat the incoming fresh air. This is critically important to provide a controlled source of fresh air in the air-tight environment of the thermal envelope.

In milder climates, exhaust-only ventilation system can use air-to-water heatpumps to transfer warmed exhaust air to heat domestic water and hydronic space heating.

Total Heat Loss Coefficent (HLC) is the heat loss rate for each degree of temperature difference between the inside air of the thermal envelope and the outside air measured in Btu per hour per degree Fahrenheit (Btu/h-°F). It the total sum of heat loss through all building components (walls, windows, doors, ceilings, basement walls, floor,etc.) due to conduction, infiltaration and ventilation. When multiplied by the indoor/outdoor temperature differential, it will provide the total home heat loss, but only for a point in time.

HEAT GAIN

Superinsulation design does not by itself increase or decrease heat gain mechanisms, but by intentional construction and design techniuqes takes full advantage of heat gain mechanisms to increase the home's energy efficiency and to reduce the home's heating load. While a home in a cold climate is losing heat through the heat loss mechanisms mentioned above, it is also gaining heat through three basic mechanisms:

1. Intrinsic heat gain is the embodied heat source produced from processes and activities occurring within the home - lighting, cooking, bathing, hair drying, human metabolism, appliances, refrigeration, etc. In a non-superinsulated home, most of the intrinsic heat is insignificant in comparison to or lost though high levels of conductive, infiltration and ventilation heat loss. In a superinsulated home, intrinsic heat sources are available for the heating of the home. The level of intrinsic heat gain available will vary depending on the activities occurring and when they occur, e.g. a television generates intrinsic heat, but only when it's in use. In a typical home, intrinsic heat can amount to between 2000-3000 Btu per hour.

2. Solar heat gain though either passive design or active collection systems can add significant heat gain depending upon the latitude of the home, the time of year, the amount of sunshine and cloud cover, the orientation of windows and the amount of shading. Maximum solar heat gain is typically received at midday between 10 am and 2 pm. While advantageous to receive this 'free' solar heat gain, it is not an imperative to successful superinsulated design.

3. Auxiliary heat gain is simply the the additional heat required through some controllable heat source to maintain comfort, i.e. the difference bewteen the home heat loss and the sum of the intrinsic heat gain and solar heat gain. The amount of auxiliary heat required will vary throughout the heating season and during each day. In superinsulated homes, the auxiliary heat gain requirement is so reduced, it is often a problem to design a heating system that is small enough to provide the required auxiliary heat.

BALANCE-POINT TEMPERATURE

The balance-point temperature (B-PT) is the outdoor temperature at which the total heat loss (HLC) equals the intrinsic heat plus the solar heat gains. When the outdoor temperature is at or above the B-PT, no auxiliary heat is required.

BP = Ti - [intrinsic heat input + solar heat input] / HLC

The balance-point temperature will vary throughout the day as the intrinsic and solar heat gains vary. Since superinsulated homes have a lower heat loss coefficient (HLC), they tend to have a much lower balance-point temperature (B-PT) even without solar heat gain. Factor in solar heat gain and the B-PT falls even further.

Typical heat loss / heat gain calculations used for mechanical equipment sizing assumes an average 65°F balance-point temperature as most homes have lower levels of insulation, are prone to air-leak infiltration and have exhaust-only ventilation systems.

In a superinsulated home with higher levels of insulation, air-tight construction and controlled heat recovery ventilation, the average balance-point temperature could be 42°F or even lower. This reduced B-PT can dramatically reduce the number of degree days (measurement of the difference between the average daily outdoor temperature and a specified base-point temperature) when auxiliary heat is required and could reduce the heating season from 8 months to 4 months. In essence, the lower balance-point temperature of a superinsulated house is the overall reason behind why superinsulation design techniques can so dramatically reduce the daily/seasonal heating load and cost for a building.

Now that the principles of superinsulation have been outlined, my next postings will provide several home designs and detailing that incorporate these principles. They will represent a series of solutions, but are by no means the only solutions. Any home can be superinsulated and alternative construction details exist and are possible if the basic principles of superinsualtion are understood and utilized as a total design system.

Many of the principles and concepts presented in my posts are gleaned from "The Superinsulated Home Book" by J.D. Ned Nisson & Gautam Dutt published 1985 by John Wiley & Sons. Most of the principles they presented in 1985 still hold true today and are still in practice. Unfortunately the book is no longer in print, but can be found in some public libraries and on Amazon for a price (I was lucky and got my copy for $35). If you are serious about building a superinsulated house, I would highly recommend investing in this book.

INSULATION & SUPERINSULATION

Superinsulation is not a material, it is a system consisting of thermal insulation plus other building components which, when designed and installed properly in concert with each other, produce superb thermal performance in a home or business. Proper installation and design are paramount.

HEAT TRANSFER

In case you were sleeping during your science classes, let's begin with the basics. Heat is transferred in three ways --

1. Conduction is the movement of heat energy (from hot to cold) through materials. Different materials conduct heat at different rates. That's why a down filled jacket is warmer than a fleece lining. Hold the end of a knife over a flame and the heat will travel to the other end. Heat inside a house is being conducted through walls, ceilings, windows, doors, etc. to the cold outside.

2. Convection is the transportation of heat energy by a moving fluid - water or air. Natural convection is fluid movement resulting from temperature differences - principle behind radiators transporting heat energy throughout a room by convection currents or heat loss inside an uninsulated wall. Forced convection occurs when an external force acts to move the fluid - forced air furnace or wind drawing heat energy from the house.

3. Radiation is the transfer of electromagnetic energy - e.g. heat transfer from a wood stove to people or materials. Near windows warm body heat is radiated to the cool glass surface making one feel cold. If surfaces are warm, people will feel warm regardless of the air temperature. A room has a mean radiant temeperature (MRT) - the 'averaged' temperature of all exposed surfaces within the room.

INSULATION

Insulation reduces heat transfer through walls, ceilings, windows, doors, etc. by dividing the large interior space of a building component into thousands of tiny air pockets. It is not the isulation material itself that creates the thermal resistance, but the low conductivity of the still air created by these air pockets. All insulation materials - fiberglass, mineral wool, cellulose, straw bales, foams - work by the same principle. Each material is given a conductivity rating (R-value) that measures its thermal resistance to heat transfer. Convection heat transfer is virtually eliminated because the air is trapped and prevented from moving. Radiant heat transfer is greatly reduced because long range infrared radiation is absorbed and/or scattered.

SUPERINSULATION

Insulation

Easy enough, pick an insulation material with the highest R-value per inch! Not so fast. Remember that superinsulation not a material, it is a system. Superinsulation also avoids thermal defects that can reduce the overall thermal resistance of the building components:

• Insulation Voids: The component spaces must be totally and completey filled. For example, a superinsulated wall or roof installation should have as many voids as roof leaks or plumbing leaks - none. If a wall had 5% overall insulation voids, its overall resistance could be reduced by up to 25%.

• Thermal Bridges: Thermal bridges are points or components with relatively low thermal resistance that intrude or 'bridge' through the insulation layer of the thermal component - studs, rafters, plates, window & door openings, corner framing, etc. Unlike insulation voids being addressed by thorough and careful installation practices, thermal bridges are addressed through proper design detailing.

• Air Intrusion: Even if air is not allowed to flow all the way through the insulation system, it can degrade overall thermal performance by merely penetrating the insulation from one side.

• Convective Loops: Wherever there are hollow spaces around insulation in a wall or ceiling, heat can be transimitted through the system by convection, even if the insulation is completely sealed agains leakage or air intrusion and no inside or outside air penetrates the system. Faced insulation batts stapled to the side of studs leave an air gap between interior finish and he insulation facing. Voids in hollow concrete block walls can develop convection loops cooling the wall. Air chases around a flue can transmit warm air to the attic.

• Moisture: Moisture comes from human activity - breathing, cooking, bathing, plants, etc. Moisture can degrade the thermal performance of insulation by convection - moisture moving into insulation through gaps - and diffusion - moisture moving through materials. All insulation systems have a dew point - the location within the system where water vapor will condense into water due to temperature.

Air/Vapor Barriers

Air-tightness is a crucial element of the superinsulation system and requires careful attention to detailing and workmanship. Heat loss by poor installation of air/vapor barriers can negate all the beneifits of well installed insulation and can even result in building damage. Air/vapor barriers in a building system will be shown in greater detail when we look at construction detailing in later blogs.

The most typically used air/vapor barrier in buildings today is 6 mil polyethylene sheets. The air/vapor barrier is always located on the warm side of the exterior wall systems where it is will be above the wall's dew point temperature to prevent condensation. Practice over time has shown that an air/vapor barrier can be installed 1/3 of the way into the warm side of the overall insulation and still work effectively. This will come in handy later when electical and plumbing needs to be run in the wall system.

The air/vapor barrier must be meticulously sealed at all seams and at all penetrations including windows, doors, outlets, plumbing, vent stacks, vemt fans, etc. Techniques will be discussed later when we look at constuction details. The air/vapor barrier must be protected throughout the building process and all damages must be repaired as soon as they occur. Before any interior finishes are installed, the entire house should be blower door tested to insure air-tightness of the thermal envelope.

Air Barriers

An air barrier is typially installed on the cold side of the exterior sheathing. This is commonly referred to as 'house wrap' in the building trade, e.g. TYVEK - a spun-bonded polyethylene. Unlike the air/vapor barrier that blocks both wind and vapor penetration, air barriers protects the insulated walls from air intrusion and makes the thermal envelope tighter, but allows water vapor to pass through to the outside. Care should be taken to tightly seal all wall penetrations (windows, doors, vents, etc.) and to tape all overlaps in the air barrier.

Support Structures

These are the structural elements or structural frame of the building - what holds up the building. Support structures must also (1) provide adequate containment of the insulation materials while minimizing the effects of thermal bridging, and (2) provide adequate support of the air/vapor barrier and the air barrier.

For the purpose of my blog, wood frame construction and materials typical of the maritime region will be incorporated. While I will be using double stud wall construction techniques in most details, other walls systems have successfully been used in superinsulated houses, e.g. 2x6 stud wall with rigid insulation as exterior sheathing; TJI joists used as wall studs; strapped walls; larsen trusses; straw bales; etc.

For the purpose of my blog, roof framing will incorporate raised heel trusses and parallel chord trusses to allow for full thickness of insulation material over the entire roof area. More later.

In my next post, I will be discussing heat loss, heat gain, and how superinsulation techniques can dramatically reduce the overall yearly heating requirements of a building.

Many of the principles and concepts presented in my posts are gleaned from "The Superinsulated Home Book" by J.D. Ned Nisson & Gautam Dutt published 1985 by John Wiley & Sons. Most of the principles they presented in 1985 still hold true today and are still in practice. Unfortunately the book is no longer in print, but can be found in some public libraries and on Amazon for a price (I was lucky and got my copy for $35). If you are serious about building a superinsulated house, I would highly recommend investing in this book.

SUPERINSULATION - AN INTENTIONAL CHOICE

Why would I propose the use of superinsulation building techniques is the design of a new home or business? The rationale comes down to intentional living. We are faced with choices throughout our lives, but all too often we do not make conscious decisions. We rely too heavily on the status quo. We find comfort in following the mainstream. My wife and I have made the decision to develop a lifestyle based upon our own intentional choices. The concepts of superinsulation would be one of those choices.

We live in a cold climate, on the Northumberland Strait of New Brunswick, Canada. To live in this climate we need to make choices to include staying comfortable during the long winter months with a minimal impact on the environment. When I lived in Missouri, my winter coat included a waterproof wind breaker with a removable fleece lining. Now that I live in New Brunswick I needed to upgrade to a longer, down filled winter coat with an internal wind break. My new NB winter coat cost me a bit more than my old Missouri coat, but the benefits I receive are well worth the added cost.

Choosing superinsulated design for a home is a similar choice. We build homes on what are common building practices. Homes built today are better insulated than homes built prior to 1970. However, we still rely too heavily on heating systems to provide our comfort. Superinsulated design begins from the premise that if we built higher efficency into our homes, we would spend much less to heat (and cool) our homes over time. The additional 5-10% in construction cost would be more than offset over the life of the building not to mention the additional comfort provided. What are some of the benefits:

• Reduced Heat Loss = Lower Fuel Bills: The heat loss in a superinsulated house is 60-80% lower than that of a pre-1970 conventional house, with a 80-90% reduction in annual fuel cost.

• Few Architectural Constraints: Almost any housing type or style can be built using superinsulation principles. However, some are better suited than others.

• Microclimate Is Not Significant: While wind protection and solar orientation are desirable, they are not critical factors in the building design and operation.

• Macroclimate Is Less Important: The superinsulation principles are applicable to most cilmates with the exception of severe extremes.

• No Need To Retool: A superinsulated house can be designed using local materials, trades, and building techniques, but with refinements. The one new and important constraint placed upon the the building industry - a stricter attention to quality.

• Do Not Require Sacrifices: Sperinsulated homes can have better air quality, can have plenty of natural light, provide even temperatures throughout, eliminate drafts, eliminate cold surfaces, control humidity, and are quiet.

In future posts, I will discuss how a superinsulated home works and provide some examples of homes based upon traditional housing types found in the maritimes.

Many of the principles and concepts presented in my posts are gleaned from "The Superinsulated Home Book" by J.D. Ned Nisson & Gautam Dutt published 1985 by John Wiley & Sons. Most of the principles they presented in 1985 still hold true today and are still in practice. Unfortunately the book is no longer in print, but can be found in some public libraries and used on Amazon for a price (I was lucky and got my copy for $35). If you are serious about building a superinsulated house, I would highly recommend investing in this book.

PROLOGUE

My research into superinsulation led me to PHIUS, the Passive House Institute United States, located in Urbana IL. This is the North American branch of the PassivHaus Institute located in Germany. They are known for developing standards and procedures for the design of buildings using passive house principles. If one wishes to get into the technology and engineering of passive house design, I would recommend contacting them. For local contact I would suggest their certified Canadian consultant located in Nova Scotia.

What I have found is a general lack of actual details and drawings that incorpoarate passive house design. The designs and details that I will be sharing on this blog are derived from many of the principles that PassivHaus and PHIUS have developed. I will not, however, try to demonstrate how my designs and details are in complete compliance with all passivHaus standards. While it is important to acknowledge the science behind passive design, residential housing has developed through commonly held and known practices. The Canadian R2000 program has developed many of the building practices and techniques that will be required for future superinsulated homes.

The designs and details I will share are based upon traditional or vernacular housing types that are common to the maritimes. These traditional housing types were developed in response to the environment and culture of this region. House designs I intend to include are:

Maison Grande-Digue House
Home design built for veterans returning from WWII.

Maison Cocagne House

Traditional house type that features a central dormer.

Maison St. Thomas House

Hillside home or cabin designed for the coast of Nova Scotia.

Maison Scoudouc House

Small single person or couples homes.

Traditional wood frame construction is used as the trade or way of building is common and known by local trades. Materials were also selected on the basis of local manufacturers and availability. While all the materials may not meet the most stringent passivHaus requirements, they will offer dramatic improvements over current building practices. The details will include the names of these products.

The construction drawings and details that have linked in my blog and those I will be including in my future blogs can be downloaded and printed for your use. These details only reflect one approach to building a superinsulated building. There are no doubt others that have been used and may well be better than the ones I have provided. I would love to see and share drawings and details with others.

Finally, I am including a link to Greener than green, a testimonial about a passive house builder and his home located in Oregon. It says more than I can write in this blog. You can find our more about Ted Nickell by typing his name into your search engine.

BEGINNINGS

This is the beginning of what I hope will be a resource for those interested in the idea of superinsulated home design. The idea of superinsulation began in response to the 1970 oil embargoes. With rising fossil fuel costs the concept is once again receiving public interest. Working with the Cocagne Sustainable Development Group, we have been developing designs for superinsulated homes based upon traditional home designs and using concepts developed by the PassivHaus Institure of Germany. This is a model of our first design - The Cocagne House. In the future, we plan to share the details that we have been developed for building a superinsulated house in our region.