James & Cill's New Home
Built by us and our son Carl
Candler, N.C. (near Asheville)

Our attempt at a zero fossil fuel heated house


Click for wide angle view of house site with
 Mt Pisgah in distance

See bottom of page for Building Science Information on the house

Links

HOME

Picture as of 3/2013

Picture as of 12/22/2011

All thumbnail pics can be clicked for full view

Clearing of the land.  This involved over a month of cutting brush and trees with many bonfires to clear the property.  We then had to tear down the old barn which was in poor shape and blocking the view.  Finally we needed to the old 70 foot mobile home removed.

Background Info

See bottom of page for Building Science information on design of home

After selling our boat we decided we wanted to settle down in the mountains of western NC. 
We chose Asheville because of the weather, beauty of the mountains, great music and great food scene.
James looked at over a 100 properties.  We wanted one with a view, power, septic, and well in place. 
We found a great property just outside Asheville.  Small lot (1 acre) but is sided by a horse farm which gives the property great privacy.

House Plans

Remembering the nightmare for framing the first house we lived in - Click Here - we wanted to keep the design a simple rectangle, 24x40 with cathedral ceilings and open floor plan with interior walls only being 7' high.  With 12' peak for ceiling this gives the appearance on one large room.

Here is floor plan with decks

Feb 2013 - got our CO and have moved in.  We are 99% done and built the house for $37.000

See bottom of page for Building Science info on home

 

 
May 2011 - Mobile home being picked up a room at a time and placed in large truck.  This equipment was able to roll the frame and axle up into a ball and dumped into the truck.  In about 4 hours the whole mess was gone

 
Old barn torn down and wood salvaged for greenhouse and chicken coup

Start of Construction - Late July 2011
Framing Detail Used, click for image



 5/27/11 - Laying out the stakes to begin
digging of holes for poles


7/21/11 - Digging 17 holes for the pole footers, we then built frames and mixed the concrete for the pads - Total cost for our foundation - under $700

   
7/22/11 - 1st Pole in the air, very hot day but we had the first piece of lumber
vertical, we had a celebration that evening, Second Pic is 5 centers poles up.

     
Center poles up with First Girt support in place.  Center poles only come up to floor level where we will add another 12' pole.  We could not get 26' poles for center poles of house, 2nd Pic - finally something to stand on in the air


7/27/11 - This was our 1st 20' pole to get vertical and standing on open concrete pad.  We spent entire day trying different methods, dropping the pole 3 times.  Finally with ropes and come-a-long we got her vertical.  After we had a system it took us about 1 hour to get a pole up and plumbed.

 
1st pole tied into center line with 1st floor joist. 

          
     
Poles going up and floor framing started

 
2800 lbs pile of subflooring sent on house by fork lift, we were happy to see that house did not fall down.  2nd pic of sub floor installation


Upper girts started for roof joist support

   
Rafters
- 102 16' 2x10 rafters, Carl and I were glad when the last one was in place

            
Rafters nearing completion

    
Beginning to frame the walls


Note double wall detail is open at top to roof joist cavity and is also open at bottom to floor cavity allowing continues thermal barrier with little thermal breaks


Double walls framed and LVL beam in place  We had to span 20 feet and skip a pole because of location of septic


Break Time, we now have water proof roof to keep rain and sun off our work


Zip system roof deck complete along with installation of chimney for Jotel woodstove

 
Start of wall sheathing, we used the ZIP system which gives us an airtight and water proof wall system


Stairs from our car parking area up to house.  They actually passed code inspection the first time around

 
Start of our metal roof.  Installation was fairly easy being that Carl and I had never done a metal roof

  
We got a pine French door to go in  opening on the right.  Found pine door slabs to match as windows and got an Amish company to make the munion bars.

     
AppleBlossoms staff member (Eddie) damp
 spraying 10' walls with cellulose


Walls blown and trimmed off to studs

 

 
Purchased the D and the E ring for my blower door.  We are now able to get a reading with the D ring, not sure if I will get to the E ring


Ridged insulation going up over OSB interior air barrier

 
Kitchen getting started, we got a close out at Ikea and got kitchen for $1800.  Second Pic is with corrugated metal wall installed.

March 2012 - Dining, Living and Office area nearing completion.  We used a dark
metal corrugated metal for ceiling and wainscoting. 

     

April 2012
  
New Hickory Flooring installed
 

Jan 2013
Interior nearing completion, been a long time, over 4000 hours of labor

Bedroom Completed.  We built the bedroom just big enough for a King size bed and room to walk around the bed.  No furniture except small light stands.  But the room does not feel small as you can see 24 feet across the hall to bath and 30 feet out to dining room through door ways.  Also with only partial walls and cathedral ceiling room feels spacious.

 

We had enough space in the floor plan to have a full walk in
closet which is 11x4' in size

 

 Toilet room and bath closet doors - used cheap Luan doors and covered with metal and Cedar, last picture is bath sink area with curved metal ceiling.  Had lots of fun with the metal galvalume roofing metal and did a curved piece over bath sink.

     
       

In wall to toilet room used glass blocks to allow lighting from window and bath lights in.  Used drip edge for the molding around the blocks and electrical conduit for trim

Our bathroom does not have a door into the main area of the bathroom but has doors on the water closet (toilet room) and the changing room for the shower.  We had just enough space to make the changing room into a sauna. I used a one piece shower kit to avoid any seams to leak and used cedar for the ceiling.  Built a cedar door to shower to keep heat in sauna.  For low maintenance we went with a cheap shower curtain that can be changed when dirty.  Floor of sauna is cheap Ikea Achia wood raised tiles.  Makes a pleasant changing room. 

 


 

Kitchen and Dining area open to living room.  With the high dark color
 ceiling the room feels very spacious.  2013

Kitchen

   

   



Homemade Pot rack from 2x4s and electrical conduit

Dining Room

    

View of deck from Dining Area and view back to dining room

 

Living Room and Office


 

Pantry/Laundry Room (wish it could have been larger)


Hall
Flooring & Wood Stove

 

 

 

 
Cill and I day first pole went up on 7/22/12, House up, roof on, insulated, and
windows and doors in by Nov or 4 months later, Carl took the pictures

 

For those in the Building Science Industry. 

Jan. 2014 Update on Building Science numbers we have achieved to this point

Blower door reading - 108 CFM50
0.71 ACH @ 50PA
0.12 CFM per ft2 floor area, 0.04 CFM per ft2 surface area
Correlation Coefficient = 0.99323

To have hit the Passavhaus standard we would have to be at 0.6 ACH@50 Pa, we came close but on the total KWh's we may hit the standard.  Have been in the house now for 15 months and total KWh's are averaging 12 KWh per day or 400 per month app.  This includes baseload, mini split heat, and electric DWH.  I believe when we get our solar hot water in we should cut this usage by 40-50%.

Our heating load for each winter we have been in the house has been around 5 million btu's.  and since we heat with wood that amounts to about 1/5 cord of wood.  This figure is a little skewed in that my wife likes to keep the house at 75-78 degrees.  The heating cost should be close to zero fossil fuel usage when we get out solar hot air collector installed on the south wall.  We only need a small fire when temps are in low 20's. 

Our HERS rating comes in at 38 and our Manual J calculation is under 10,000 Btuh


Here was my thought process on the
 design and building of the home

1. Floor plan would be just large enough for two people plus the furniture we had.  One bedroom so the kids could not move back in, very important.
2. Building as small as we could would save on construction costs, save on energy cost, and be easier to maintain and clean.
3. By constructing the shell to a high energy standard we would not need expensive ground source heat pump, large south facing glazing for passive solar heat (you then need expensive window coverings to keep heat loss low at night), or any other fancy energy measures to have low heating bills.
4. Open floor plan to make the space feel large.  Our bedroom and the bathroom only have 7' walls while the house has a 12' cathedral ceiling.  From most places in the home you can see the full 24' width and the 38' length of the one big room.  This with the high ceiling gives a feeling of a much larger space than it really is.
5. Keep my window area to less than 5% of the floor area and concentrate the window area to the SW side of the house where we spend most of our time and get the heat gain in winter, summer this glazing is shaded by two very large oak trees. 
6. Large overhangs to protect doors and windows from the elements and white reflective metal roof.  Reflective metal siding as well to down summer heat gain plus be a durable low maintenance surface
7. Function would trump form.  Wanted each room to function well for the designed purpose of that room regardless of looks.
8. I do not like normal thus we used a lot of building materials for purposes other than the intended use such as galvalume corrugated metal for many of the walls and ceilings, electrical conduit for molding and metal drip edge for trim.
9. Low maintenance - Roof would be good quality metal (light color to reflect summer heat) and walls would be galvalume corrugated metal for low maintenance.
10.  For air tightness and wall moisture issues all electrical wiring and plumbing was surface mounted, thus no wall penetrations
11. Keep width of home to 24' so I could use 16' rafters and have good overhang to protect house walls and windows

But the over riding design tactic was "Keep it Simple"
 


Overall Construction Technique

As with the first house I built 40 years ago I went with "Pole Construction".  There are several reasons for using pole construction.


Click for view

  1. 1. Pole construction allows for a cheap foundation.  We spent $500 for a couple of hours of backhoe digging then built frames to pour a 2'x2' concrete pads under each pole.  Cost with concrete was under $700 which put our foundation a fraction of the cost of normal construction

    2. With pole construction we were able to use longer 6x6" poles and raise the house 7' off the ground.  This served two purposes - gave us 900 Sq Ft of free space to park our vehicles, store our firewood etc plus we are not taxed by the county on this space.  The second reason was to get our house up and away from the ground for moisture reasons.  Very dry house and no damp crawl space to deal with  In all my years of home inspections I have never seen a basement or crawl space I would want under my house.

    3.  With pole construction the wall are not load bearing.  This means less lumber in the walls (no headers over doors and windows) and allowed us to put the roof on first and build out the balance of the house without our wall and floor material getting wet.  From an energy standpoint there are no headers over doors and windows thus no thermal breaks. 

Shell

We have 40 plus R-values ( 0.025 U-Value) in walls, ceiling, and floor, considerably under Energy Star for our climate of 4100 degree days. 

Walls are double wall construction (two 2x4 walls) to minimize thermal breaks.  The walls have two skins similar to a SIP system  The exterior covering is the ZIP system, with all seams taped and caulked.  The ZIP systems is our moisture plane but breathable.  The interior skin is OSB board with seams taped and caulked.  No vapor barrier as I wanted the wall system to be able to dry both directions depending on whether I was heating or cooling the house.  Because none of the walls are load bearing the only thermal breaks (no headers etc) are the 8 poles within the walls.  As seen in the picture here my thermal envelope extends up between the two girts right into the ceiling cavity.  I left the subfloor open inside the walls so the cellulose extends also down into the floor joist cavity thus giving me a continues thermal envelop around the whole structure with no thermal breaks to speak of.  Between the walls, ceiling, and floor we got 193 bags of cellulose installed, 5700 Lbs of cellulose.  I had measured my cavities in the walls, floor, and ceiling and calculated we needed 191 25lb bags to achieve 3.5 pounds per cu. ft.  We actually got two more bags into the house.
 

Mistake made - 2x10 blocking was used to close off the ends of the rafters.  I wrongly assumed the high density cellulose would prevent air movement at this section of my envelope.  Wrong - I should have foamed this area and thus would have hit the passive house standard of .6 ACH @ 50.  This question arises  why my inside skin did not stop the little air leakage I have.  In talking to Gary Nelson  at the Energy Conservatory he informed me that OSB is very leaky and I would have had to paint it as they do with their test rooms to lower my blower door number.  Did not do this as I wanted my wall to be able to dry to the inside as well as outside.

Ceiling -  have high density cellulose between the 2x10" rafters.  Then a skin of OSB.  Unlike my double walls with no thermal breaks my rafters presented the problem of a large percentage of my ceilings with a thermal break.  To eliminate this break we installed 1 inch of ridged insulation over the OSB skin then our metal ceiling over this.  I used foam board with a reflective surface facing towards the heated space.  With the corrugated metal I have about 50% of the ceiling having the ability to reflect the heat back towards the metal. Not sure if this does much good, no way of measuring the effectiveness but figured it could not hurt.  Click image to see details.


I am not spending the money to have the house certified as a Passavhaus but think we will come close the German standard for a Passavhaus.  Click Here for what makes a house a Passavhaus

We are already well below the Energy Star standard.  For North Carolina that is 5 ACH@50 and we are at .07


Moisture and Mold Concerns

Of the three driving forces in the planning stage, Cost, Energy Use, and Moisture control, moisture issues were one of my biggest concerns.  In my years of housing inspections I have seen many homes destroyed by moisture.  I have lived in homes where leather coats and shoes would grow mold in the closets.  I have never seen a basement or crawl space that I wanted under our new house.  Following are some of the design ideas we used to reduce the moisture issues so common in many homes:

- No roof penetrations to leak, vents went out side of house

- House built 7 feet up off the ground to get away from ground and moisture

- 4 foot overhangs to keep rain off siding, windows, and doors

- Closet has levered walls, open ceiling to house, wire shelves and drawers to promote air circulation

Even as tight as the house is we had no condensation on our windows during the winter


Heating Systems

My wife having grown up in Vermont wanted a wood stove, I love her so she gets what she wants (most of the time).  We purchased the Jotel F 602, the smallest unit they make.  Wish it had been available with outside air intake but would have had to go with a bigger model for that.  We can take the chill off the house by burning our junk mail sometimes.

Our other heat source is a Mitsubishi 1 ton mini split, HSPF 8.2 with a SEER of 17.  Wanted a half ton unit that they now make with a 27 SEER but our local heating company sold me their floor model for $900.  Could not pass up the deal.  We do not anticipate using air conditioning so it will not be oversized.  We believe in fans for the hot days and here in the mountains, last summer, I could cool the house down by night ventilation, close the windows in the morning and house stayed very comfortable all day .  This unit has a very efficient drying mode we may use from time to time when weather is really humid.  Our maximum heating load was calculated to be 5,200 btu/hr. 

My only gripe about the mini split is that I can set the thermostat at 65 to have the unit come on during the night if heat was called for, but this model unit does not shut off.  Runs in sort of a coasting mode pulling air through the wall unit to sample air for thermostat.  In this coasting mode it put out a small amount of heat and in our house this overheats the house.  I have many times left the unit on set to 65-67 degrees and it heats the house to 72 plus.  Am looking for a high voltage thermostat that would solve this problem.

With both heating sources in the living room I was worried the far side of the house, where the bathroom is located, would be cold.  But the entire house stayed within 2 degrees temperature from one end to the other.   Made me a happy camper.


Cooling Needs

My design ideas for cooling are paying off.  We are into July and are able to have a very comfortable house with no AC.  Here is how we achieved this:

- We have a light color reflective metal room and and reflective metal walls thus no solar thermal gain during the day

- Our main area of glass on the south west side of the house is shaded by 3 large oak trees, thus we are using vegetation for cooling

- We have 4 foot overhangs to keep sun off walls and windows

- Have built outside cooking area to keep cooking heat out of the house.

- Night are cool here in the mountains, we vent house at night and shut the house up in the morning, house stays very cool all day


DWH System

We built a small 10x12 room under the house with a dirt floor and a small raised pressure treated platform to hold our 40 gal. hot water tank and well pressure tank.  This room will also be our root cellar.  I am stripping 2 old DWH tanks and will plumb them in ahead of my hot water tank.  They will serve 3 purposes.  First they will temper our well water before it goes to the hot water tank, second the cool tanks will cool our root cellar, and third we will have 100 gal plus of potable water if grid is down.

Will be building a simple solar water heater this summer and hope to upgrade the system to produce the majority of our hot water needs in the future.


Performance so Far

Well we have been through our first heating season, here in Asheville winter was setting in when we moved in mid December.  As best as I can calculate we used app. $40 worth of electric running the mini split heat pump on occasions and burned app. 1/8 cord of wood.  Many times we built a small fire in the evenings for the ambience and had to open doors to dump heat.  Would take the house to 80 degrees very quickly.  We found though letting the small fire die out before going to bed the house would still be 72-75 degrees in the morning with outside temp's in low 20's.   

Several times I baked bread in the evenings and the heat from the oven would carry the house all night and still be over 70 degrees in the morning with outside temp's in the low 20's.  We rarely get below 20 degrees here in the mountains, why do you think I moved here.  Also does not get real hot in the summer.  Perfect climate for the east coast.


Can we hit zero fossil fuel energy for heat?

I believe we have a shot at it.  As best as I can tell our internal heat gains offset the heat loss down to about 38-42 degrees, below that need some heat in put.  I plan to build a 8x12' solar heater on the south side of the house much like the window box heaters.  I think with the amount of sun we get here in the winter I can heat the house during the day and temp should hold over night.  The house only drops a couple of degrees overnight and really holds the heat generated during the day.

On the baseload side when I get my wife's thermal nuclear clothes dryer installed (ie clothes line)  and our solar hot water system installed I believe we can get down to app. 200 KWh per months which would put us well under the Passive Haus standard.  I still have a few light to change out and we will be at total LED lighting. 


IAQ Issues

This issues after living in the house through the winder was a surprise.  I assumed we would have high humidity issues etc and had fully planned on a HRV or ERV system for the house. 
At this time my only way of measuring if the house needs fresh air is the humidity levels.  But we never went over 60% during the winter.  I plan on getting a CO2 monitor to have a better idea when house needs vented but have not had the extra $200 plus to purchase yet.  So with a house at 108 CFM@40 what is going on? 

Here is best current guess at this point.  My Panasonic 80cfm bath vent runs for 20 minutes a day with two showers.  If have it programmed to run for 5 min. when shut off after shower.  So there is 1600 cfm of air turnover.  Doors are opened probably 30-50 times a day, we are both smokers but go outside to smoke.  When cooking and producing a lot of steam we use the kitchen vent.  These forms of venting would not be as effective on a 4,000 sq ft house as they are on our small house is my thought.

Lastly we like the wood stove for the ambience and heat.  Not sure how to calculate the volume of flue gas going up the chimney but best guess is 20-30 cfm's.  So in essence the wood stove is ventilating the house by pulling a small amount of fresh air around my bath and kitchen vent dampers and small amount of leakage on doors.  So unless our CO2 meter shows readings of 800 plus ppm of CO2 next winter we will forgo the HRV system.  If CO2 reading are high probably will forget the HRV system and put in small intake on the solar box heater and use the Panasonic fan set at 20-30 cfm's during the day and pull heated air through the house with this method.  Stay tuned, it is a work in progress.


Tight House Issues

We have had some interesting issues with a super tight house.  The house is tight enough that when you open the door the bath and kitchen vent flappers make noise.  If we have a small fire in the woodstove smoke is pulled out of the stove by opening the front door.  We quickly found we could not have a fire and run the bath vent or clothes dryer.  To solve the problem I installed a 4x10" vent in the floor by the woodstove ducted to the outside.  We now crack this vent open when running the wood stove, problem solved.  By the way my 80 CFM bath vent can take the house to negative 12 Pa and with the kitchen vent and bath vent running at full steam can take the house to negative 112 Pa.  That's tight.


Final Thoughts

We are extremely happy with the house.  It is a very comfortable space to live in, heats so well and cheaply we can have the house at 75 degrees on cold windy winter days and not feel guilty.  We went slightly over our budget of $35,000 but only by a couple of thousand dollars.  We did put in app. 4,500 hours of labor on the house, lot of detailed wood work in the house.  We both believe there is the possibility of the grid being interrupted so built the house to heat with wood, cook with propane (have app 2 years supply of propane) and will have water storage from our rain catchment system.  Will be installing a barrel high on the house and running plumbing with tee and shutoffs so we can flush the toilet if grid is down and have a Berkey water filter to make the rain water safe for drinking.  We built a storage room and have 15 months of grains stored.  We have no mortgage so can live pretty cheap in the house.

After 3 months living in the house not many things we would do different again.  Perhaps go a little smaller, could live comfortably in perhaps 700 sq ft.

Many people are surprised we were able to build the house so cheaply.  The answer is we used our own labor, built small, and used the pole construction method which saves thousands of dollars on a foundation system.  We could have built the house for perhaps $5.000 less if we had used sheetrock for interior walls instead of the metal, cedar, pine, and oak walls and ceilings.  We also used a mid price flooring, hand scrapped hickory flooring.  The last thing that helped with the cost was we knew 3 years in advance we were going to build therefore purchased and stored much of the building materials, kitchen cabinets, etc on sale.  But our final cost was app $41 per sq. ft. 

Anyone can have a Passive Haus with net zero energy if they spend the money.  30-40,000 dollars for a PV system, 12-15,000 dollars for a ground source heat pump, 5-8,000 on a solar hot water system, etc, etc.  We feel we achieved something by building an energy efficient structure in a price range for the lower middle income family range.

This summer plan on installing sub metering on DWH and Heat Pump to have a better understanding of usage on the electric baseload and heating costs plus a CO2 monitor

4/9/13 update, last night temps were in mid to upper 40's.  With nothing but internal heat gains house was at 76 degrees this morning, Sweet

4/19/13, monitoring electric usage for past couple of weeks, averaging 9 to 11 Kwh per day.

7/1/13  We have had some warm weather in upper 80's yet zero air conditioning costs so far. 

 


House Stats

Floor Area = 897
Wall Area = 1053 sq ft
Window Area = 81 sq ft
Door Area = 61 sq ft

Window to Floor Area = 5%
Net Wall Area = 902 sq ft
Percentage doors & windows to wall area = 14%
Percentage to surface area = 5%
Ceiling Area = 920
Total Gross Surface Area = 2883

Net Surface Area (minus doors & windows) = 2738
Volume = 9120 Cu Ft

Windows at .29 U-value, R-value 3.4
Surface area at .025 U-value, R-value 40

Weighted Average - .0376 U-value or 27 R-value

Year Heat Loss at R-27 or .0376
.0376x2883 (surface area)x4100 DD x 24 = 10.6 million BTU's of heat needed, 4-5 million though gained internally from body heat, lights, fridge, computers, etc. But this number is wrong because it is based on a base temperature of 65 degrees.  My best guess for our base temperature is about 38 degrees.  Above that temperature our internal gains offset the losses. 

I suck at math so above calculation may be all screwy.

Finally my thanks to Apple Blossoms and John Meeks for the free cellulose blowing of the home and our son Carl who took off work for a few months to help Cill and me get the poles up, roof on, and sheathing on the house.

 

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