Tuesday, October 24, 2023

Construction -- Interior Casework -- A Progress Report

 It's been a little over 9 years since we broke ground.  That it has taken this long to be within a few months of finishing shouldn't be a surprise considering our unwavering insistence on time as the variable and quality the constant, that we would spend whatever time necessary to do things as well as we were capable.  And, of course, much of what has gone into the project is entirely without precedent and therefore much more inefficient and time consuming than standardized construction.  Then add DIYing.  I lacked experience in the "real" construction world and, when assisted, it was mostly by other DIYers.  

The interior casework has followed the same pattern but even more so.  Doing it with raw sawmill lumber has been extraordinarily time-consuming, not even counting the time it took to sticker and dry the green lumber.  The advantage of using sawmill material, though, is that it lowers costs sufficiently that a committed worker with the proper shop equipment can produce high grade casework at reasonable cost. 

(Reminder: click on any picture for an enlarged view.)

Acclimating the Sawmill Lumber

Sawmill oak for interior trim
Using the saw table as a "paint station" when the
dedicated area for staining and painting was not enough.
The rough red oak for the interior trim was purchased from a local sawmill.  Since its lengths, widths and thicknesses had to vary to meet our needs, its sawing was done while I watched/helped.  It was "stickered", meaning carefully stacked in level layers separated by thin strips of wood (the stickers) and covered with corrugated metal roofing.  Thus it was protected from direct rain, snow and sunlight but was open on all sides to circulating air so that the sap in the wood gradually dried over time without warping.  The recommended drying time is at least a year but longer is better with the knowledge, however, that stacking too long risks "sticker burn" which occurs when the stickers cause discoloration in the milled lumber.  Fortunately, we saw sticker burn on only a few pieces despite our extended timetable,   And our extra effort in stacking and stickering paid off when even the longer pieces were straight and easy to mill.  When crookedness did occur, the boards were usually okay flatwise but somewhat bent, mostly around knots close to the edges of the boards.

Milled lumber in vertical basement
When it was finally time to begin work on the interior trim, the sawmill lumber was de-stacked and stored for awhile in the vertical basement of the house so as to acclimate to the interior temperature and humidity levels.  Thus, its moisture content was matched to that of the house so that the fit of the installed woodwork would stay tighter over time.

Milling and Sizing

In the garage workshop, a piece of sawmill lumber went through at least four processes to become a useable board.  A jointer was used to plane one side perfectly flat -- no concavities, no convexities, no twisting.  With one side flat,

The window sill is extra wide to hold potted plants.  Notice
in the 
background the raised metal vegetable gardens
and the fenced solar collector for the AGS system.





the thickness planner shaved the other (rough) side flat, smooth and to the desired thickness of the finished board, say 3/4" for most applications.  Next the jointer was used to true up and smooth one of the rough edges of the board.   And finally, the table saw with a long and stable rip fence was used to cut the board to the desired width, running it through the saw with the true edge against the fence.  The sharp blades in the jointer and thickness planer and a fine-tooth blade in the saw minimized the amount of sanding needed to produce a smooth surface ready for staining and "varnishing".

I milled most of the raw sawmill pieces before starting the trim work so as to know what was available to work with.  Then I segregated the pieces; first the widest for baseboards then the narrower pieces for door and window trim -- head casings, side casings, sills, aprons, plinths, jam extenders, etc. --  in order to be sure there was an adequate supply in each category to finish the job.  To my pleasant surprise, the sawmill operator and I had communicated pretty accurately on the width and thickness of lumber needed -- with one hitch -- I forgot to include jam extenders in the order but was able to use oak veneer plywood for them that blended in well enough.

Fitting, Staining, Poly-coating and Installation

We used pre-hung unpainted solid core oak veneer doors rather than making doors from scratch.  After hanging, the doors were moved one-by-one to the shop for staining and clear finishing.  And the casework was dry fitted then stained and poly-coated before installing.  Only the door frames had to be stained and poly-ed in place.

The doors and windows had been set into the 15" thick exterior walls such that that the distance between the window frame and the surface of the drywall was about 5".  The space between the window frame and the back surface of the side casings -- "vertical jam extenders" on the sides and "head jam extenders" on the tops -- was covered with oak veneer plywood after the head and side casings were already in place.  The windows are set back from the plane of the exterior wall at least 8".  Not having them flush on the outside ruled out windows with nailing flanges, making it necessary to eliminate air leakage by other means.  Minimally expanding foam filled the gap between the windows and the rough openings supplemented by generous caulking when the exterior casework was installed then more caulking as the jam extenders and sills went in.

Unique Staircase

When I approached the sawmill operator about "showy" wood species for an open riser staircase, he recommended an option new to me -- hackberry.  We stickered and dried it in the roughed-in walk-in closet lined by plastic sheeting.  Aided by a dehumidifier, it was dry by the time we needed it.

The rough hackberry was drab and uninteresting but, once milled, "showy" did not do it justice.  Pieces wide enough for 12" steps were not available but, just as well, my jointer was only 8" wide.  So the steps had to be assembled from narrower hackberry boards with a filler of black walnut interposed.  The stringers were conventional 2-bye lumber veneered with hackberry.  Clear poly-coating made the unique character of the hackberry pop and the dark walnut added a nice touch.  The store-bought balusters and handrails, stained to match the other woodwork in the house, provide a pleasing contrast to the light colored stair treads and stringers.

Doors and Window Trim

In order to mimic the country style of a bygone era, the head casings and the splinth blocks (at the bottom of the side casings next to the floor) are wider and thicker than the 3/4 inch thick door side casings and the baseboards.  The thickness of the head and side casings of the windows are dissimilar in the same way.  And the baseboards are 6" tall, definitely a throw-back. 

Filling the nail holes in the woodwork was no small task.  It was done with stainable wood filler and a long learning curve to be able to know how soon to remove the excess stain in order to reach an optimal result. The hole filling and wood filler staining nevertheless caused enough blemishing of the poly-ed surfaces that a final (third) coat of poly was required.                                                                                                                        

At the time of this writing about half of the doors and only a fraction of the windows had been finished.  Stay tuned.



Tuesday, October 3, 2023

Odds "N Ends - Estimated vs. Actual Costs - A Preliminary Analysis

It is safe to say at this stage that the cost overrun for our project will be formidable, even as much as twice my original estimate but still less than half the cost of contractor-built comparables.  (Reminder: click on any picture to enlarge it for better viewing.)

                                                 UNDER-ESTIMATING COST

A page from the original estimate
For a DIYer to think s/he could come even close to estimating the cost of such an atypical custom-built home is the definition of naivety if not insanity.  When the project is done, I will, as best I can, spend the time to research invoices, credit card statements, cash payments, etc. and compare the findings with my original estimate in order to quantify my naivety.  
In the meantime, it's interesting to look at our project in view of online cost estimates for home construction in the Midwest.  
What follows is a theoretical analysis (read: wild guess) based upon industry averages for traditional stick-built homes having some degree of customization.  

While we avoid the cost of conventional HVAC, we add costs for French drains, the various components of the AGS system*, greater volume of concrete, insanely higher R-values for the building envelope, a free-standing energy recovery ventilating system, top-of-the-line windows and doors, ventilated (double-layered) roof and compulsive air sealing for the building envelope to name some of the unique attributes of the home.  Except for the AGS system, all of the features enumerated would improve the energy performance (and raise the cost) of a conventionally built house as well.  So it seems fair to say that not having to buy and support a HVAC system (initial cost, long-term maintenance and energy consumption) more than pays for the AGS system, leaving the cost of the rest of the building fair game for comparing with conventional construction but, at the same time, realizing that "conventional construction" is merely a poor stand-in for the lack of comparables for our advanced and enhanced project.

(Spoiler alert.  If your interest level is waning already, you might want to forego the details in the next three paragraphs by skipping to the last, summarizing, paragraph in this section.)

A quick online search suggests that the per-foot cost in the Midwest for conventional construction ran $121 in 2017, a year that fell about midway through our construction period.  A figure of $121 / sq ft would bring our not quite 3,000 sq ft build in at $363K, half of which, according to the online source, would be the cost of labor with another 10% going towards contractor profit, leaving 40% for materials.  For our project, not all labor was DIY or volunteered.  Some of it was done by professionals, including a journeyman carpenter and a plumber friend.  However, all non-volunteers, whether professional or amateur, received at least $15/hr and, more often, $20, which is what I consider to be a fair range for minimum wage.  And, since we paid separately for the materials involved with all phases of construction, including the dirt and concrete work that preceded the actual build, the excavation and concrete contractors' fees were for labor only, mirroring the wages of the others that helped with later construction.  I would guess then that the ratio of hired and contracted labor as opposed to my (sweat) labor and that of volunteers would be about 
1.5 : 8.5 or 15% for paid labor and 85% for volunteer and my labor.  How that plays out in terms of dollars is the rest of the story.

First, the generic labor cost has to be reconciled to fit our situation in order to be able to consider the other costs of construction -- materials and contractor profit.  If 50% is the generic cost for labor, the labor costs for a $363K house would be $182K.  In terms of dollars, the 85%:15% ratio for labor amounts to $155K for sweat/volunteer labor and $27K for hired labor.  Subtracting $27K from the $363K leaves $336K for everything else -- contractor profit, sweat/volunteer labor and materials.  Since there is no contractor profit to be paid, all of the $336K can be allocated to materials and to the value of sweat/volunteer labor.  Since the time has not come for a tally of the cost of materials, let's assume that their cost is what is left after valuing the sweat/volunteer labor.

So where are we now?  The generic cost of labor is 50% of the cost of construction or $182K from which we have subtracted $27K for contracted labor leaving $155K for sweat/volunteer labor.  Not having to pay the 10% contractor's profit saves another $36K which, when added to $155 savings on labor means that $191K represents that part of the cost of construction for which no cash is needed.  Or, to say it another way, $191K subtracted from the total cost of $336K leaves $145K for materials and miscellaneous costs requiring cash.

So, remembering that the generic square-foot cost of construction in the Midwest is $121, how do our figures compare?   When $145K is divided by 3,000 sq ft, our per-foot cost is $48 or about 60% less than the generic cost.  My original estimate was $34 sq ft for a smaller house (2,100 instead of near-3,000 sq ft), so, on a square-foot basis, I underestimated the cost by at least $30%.  What that translates into in terms of real world expenditures will have to wait until I do the post-build analysis but I suspect that it will prove to be somewhat on the low side.  Even so, it's nice to think that my major bucket list item -- to DIY a house -- has not only kept me enthused and in better health during my golden years but will have provided a nice return-on-investment for our heirs.

UNDER-ESTIMATING TIME
                                                    
My ability to estimate cost proved to be better than estimating the time it would take to build the house and to reconfigure the surrounding grounds, largely because I grossly over-estimated how fast I could get things done working mostly alone.  Having even one other pair of helping hands throughout construction would have sped things up, not just twice as fast but three or four times faster than working alone.

Does DIYing pay dividends?  Maybe, Maybe Not.
I really did think early on that it would take only a couple of years, maybe three, to build the house.  If it could have been done that quickly, the sweat equity figure that I used above would mean that my wages would have been $57K to $85K per year.  All well and good except that construction by the time it is completed will have taken at least eight years.  Divide the $170K sweat equity by eight and $21K per year might be okay for us retirees but nothing to write home about otherwise.  So I guess the lesson here, based upon these wild-guess figures is that a person should think twice about quitting his/her day job to build a house this unique, complicated and time-consuming.  Either s/he should keep the job and hire a contractor or stick to a more conventional design such as using structural insulated panels (SIPs) that could in fact be DIYed in 2 - 3 years.  The problem with having our house professionally built is that it would be hard to find a contractor who would be willing to undertake the risk involved with a ground-breaking, non-standard project unless the owner was willing to contract on a time-and-materials basis which would probably open a bag of worms for the owner.

Dirt Work
Having never sat in a track loader, I was ill-equipped to appreciate the amount of time it would take to move dirt around for our passive solar design.  Digging into the hillside to site the house was time-consuming because of the volume of dirt that had to be moved with a 6' wide bucket and the fact that each bucketful had to be carted to the storage area behind the excavation at least 100 yards away rather than swung to the side as is typically done for basement excavations.  Lots of dirt had to be rearranged in connection with earth sheltering and for the insulation-watershed umbrella of the AGS system.  Contouring the surrounding grounds to funnel run-off to numerous rain gardens also was time-consuming. 
Salvaging lumber from one of several tear-downs


According to the hour-meter on the track loader, I spent 415 hours operating it or about 52 eight-hour days.  Within the context of my original estimate of two years and using 2,000 hours per year as working time, 415 hours would have consumed +/-10% of the total construction time.  As it turns out, 3over six years is still not inconsequential.

Pre-Assembled Wall Trusses 
I began tearing down old houses and
Jig with truss in process.
out-buildigs  and de-nailing the salvaged lumber a couple of years in advance of starting construction.  Later, when the weather interfered with the dirt work, I worked under shelter using some of the lumber to pre-assemble 30+ wall trusses for the 15" thick exterior walls.  These pre-construction tasks took hundreds of hours, mostly for processing the salvaged lumber once it was on our property.
 Altogether there were seven French drains as long as those
on the left; all were covered with filter cloth as is being done 
to the one in the middle; notice off to the left the edge the 
huge dirt storage area behind the building site.  (Click on 
 the picture for an enlarged view.)

French Drains
Knowing that the thermal mass under the house would have to remain dry for proper performance of the AGS system we enlisted the help of a soil engineer.  On his recommendation, a contractor drilled and sank four peizometers quite a few feet below the anticipated location of the AGS conduits.  Two years later during an especially wet spring and early summer, ground water rose sufficiently high in the peizometers to threaten the future AGS conduits.  The seven French drains that
Friend, Pat, laying a conduit that starts at the white
PVC pipe angling up from the trench behind the footprint
of the building and ending at the location of the future
 front foundation of the house and later to be connected
to the yet-to-be-built solar collector. 
were necessary to mitigate the problem were installed before final excavation for the house.  They took only one day with a large crew of family and friends assisting the excavation contractor but assembly of the drains from plastic culverts ahead of time took me considerable time.

AGS Conduits
Collector shell ready for backfilling the gap between it
and where the front foundation for the house would be
 situated.  By the time the picture was taken, solid PVC
pipes had been laid and buried, joining the black  AGS
 conduits with the solar collector.  Notice the terminal
ends of the conduits in the distance.
Trenching and burying the nine AGS conduits also was easily done in a single day by the contractor with several of us helping.  The time consuming part was connecting them to the solar collector on the south and managing, late in construction, the terminal ends on the north which stuck out of the ground several feet initially.  

Solar Collector Shell   
Construction of the solar collector shell out of dry-stacked concrete blocks that were fiber-bonded-cement-parged and connecting it to the AGS conduits took several weeks mainly because of heavy spring and early summer rains, and was way more physically taxing in the summer heat than I anticipated.  Once it was completed, the conduits run to it and the open pit between it and the footprint of the house backfilled, construction on the house could finally begin.

UNANTICIPATED COST OVERRUNS
The amount spent on contracted dirt and concrete work prior to the carpenter phase of construction was indeed a major surprise.  The cost of concrete itself was somewhat anticipated but the amount paid to contractors for the final excavation and pouring was beyond pale or so it seemed to me at the time being unaware of the size of their capital investment in equipment and the seasonal nature of their work in our climate.

Once that expensive phase was behind us and we started the carpenter phase, most of the overrun was for unanticipated labor and for inflation.  Otherwise, we were doing familiar things that hued reasonably close to the original budget.  Labor costs started rising when I found that I needed a second pair of experienced hands for such things as setting trusses, sheathing walls and roofs and installing metal roofing, siding and soffits as well as for some of the drywalling and blowing insulation.  The 8 years after groundbreaking in late summer 2016 was a long enough span to see inflation of the cost of materials.  For example,  the price of 1/2" drywall rose by 33% between the time I did the estimate in 2014 and actually purchased it in 2019.  The rice hulls for insulation went from $1,400 per truckload to $5,000 due partially to inflation but also other factors (as explained in one of the posts on insulating). 

And there was an exuberance factor.  I found it too easy to have the mindset that, "Oh well, we are already overbudget, so why not spend a little more for upgrades on X,Y,Z.".  This tendency manifested primarily while wrapping up the interior for such things as flooring, bathroom fixtures, kitchen and laundry appliances and lighting.
_______________
*For those who have not followed the blog enough to know about the Annualized GeoSolar system that will provide year-round comfort in the absence of conventional HVAC, click on the title under "Featured Post" near the top of the left column.

Thursday, December 8, 2022

Design - Sustainability Inventory - Part II: Living Quarters

 By now, our 8-year journey to energy independence has been documented with nearly 150 individual blog posts.  For those who may be curious about our project but not enough to wade through myriad posts, perhaps the previous Part I and this Part II will suffice.

Click on picture to enlarge for better viewing

Part I covered the non-living spaces of our passive solar home -- the grounds, the exterior shell of the house, the screened porch, the garage, the airlock and the vertical basement. This post outlines how the interior living spaces contribute to the advanced  passive solar design.

This report posts during early winter 2022 after having taken occupancy in late March.  

Common Features

            The windows are double-thickness with two kinds of glass – transparent on                  the first floor and translucent on the second

The transparent first story windows are backed up by thermal mass – the concrete floor and the soil beneath it. The solar gain through the windows warms whatever it shines on -- the floor primarily but also the furnishings which have minimal thermal mass but still contribute to warming the air.  And, the medium shade for the floor hits the sweet spot -- a dark color would overheat and a light one would reflect, rather than absorb, solar energy.


                         The fact that the windows on the
                      second floor are not backed up by thermal mass and are more                                    
numerous than on the first floor requires a different strategy for                                    maximizing solar gain during the winter.  The glass in most of the                                second story windows is translucent (frosted).  Unlike transparent                                 glass through which sunlight enters uninterruptedly and heats                                    whatever it shines on, translucent glass diffuses or scatters sunlight                            so that, in the absence of thermal mass, it heats the interior contents                            randomly and without overheating. 

The most prevalent wall color in the house is rated at 65% reflectance which is the sweet spot between reflectance and glare.  The reflective paint works in tandem with the translucent glass to scatter winter solar energy. 

Our windows, in addition to transparency vs. translucency, have three additional energy-saving features – low-e coating, fiberglass frames and swing design.

Low-e coating for a double-glazed window blocks up to 90% of the heat loss on winter nights and cloudy days.

Fiberglass frames are “greener” than the more ubiquitous vinyl frames

             Less embodied energy (made from sand rather than                         petroleum).

Co-efficient of thermal expansion matches window glass for better seal of double-glazing as well as minimizing air leakage between frame and glass; contrastingly, vinyl expands (summer) and contracts (winter) much more than window glass.  

All windows are casement or awning (both swing style) that, on closure, create a compressible weather-proof seal.  Sliding styles (double- or single-hung or side-by-side), need greater tolerances for sashes to slide freely within frames and, as such, have more potential for leakage.

Polished and stained concrete floors, in the absence of tile and carpeting, maximize the flow of heat from the mass in winter and into the mass in summer; in a few years, after the mass temperature reaches equilibrium, tile would probably work without compromising the thermal performance of the house. 

Handicap accessibility, e.g., 36” doors with lever-type door “knobs",                           elevated wall  receptacles, no grade changes between drive and house.  

Combination fire and CO alarms for sleeping areas hardwired (with battery backup).

Numerous through-the-wall ventilators that allow stale air accumulating at the high point of the sloped ceiling of the first floor to escape to the second story. 

         Continuous ventilators at the top and bottom of the tall north wall, i.e., the one           separating the living space and vertical basement, allow air to move back              and forth through the wall and either deposit or extract heat from the thermal              mass (concrete vertical basement wall and the earth behind it) depending on              the season

Entryway / Kitchen / Laundry / Dining Room

Entryway wall veneered with handmade bricks salvaged from 19th century farmhouse.

Salvaged kitchen and laundry cabinets are Facebook Marketplace finds; laminate (Formica) countertops instead of natural stone with its embodied energy (long distance importation or energy-intensive manufacturing).

            All appliances, range hood and ceiling fans are Energy Star rated.

Lowered countertop area that doubles as lunch counter and ADA-compliant work surface.

Supply and return vents for ERV system.

Living Room / TV Area

Continuous ventilators at the top and bottom of the tall north wall (mentioned above).

Wall switches for all TV and computer receptacles to control phantom loads.

Guest Bathroom

            Salvaged wainscoting for one wall

            Porcelain tile for tub surround gifted by contractor (left overs from a job)

            Recycled ceramic (rather than fiberglass) bathtub (Craigslist)

            Wash basin mounted on treadle-type sewing machine

            Low-flow faucets and shower

            1.2 GPF handicap height toilet

            Exhaust vent for ERV system

South Bedroom

            Energy Star ceiling fan

            Supply vent for ERV system

Master Bedroom / Walk-in Closet

            Energy Star ceiling fan

            Supply vent for ERV

            Repurposed closet organizer (Facebook Marketplace)

Master Bath

1.2 GPF handicap height toilet

Low flow faucets and shower

Exhaust vent for ERV

Recycled vanity with manufactured stone countertop rescued from dealer’s “bone yard” (laminate is no longer recommended for bathroom vanities)

Handicap accessibility

                        Wheelchair accessible shower with controls reachable before                                       entering spray

                        25 sq ft  of floor space in middle for wheelchair turning

                        One sink is handicap (and child) accessible

                        Numerous grab bars

Second Floor Balcony (Catwalk)

            Vents from first floor to syphon off warm air accumulating at high side of                       cathedral ceiling.

Click-together composite floating floor; composite is more sustainable than vinyl and, by being manufactured from pulp wood, is even more sustainable than conventional hardwood flooring; medium color for a balance between absorption and reflection of solar energy.

“Green” windows

Translucent window glass vs. transparent glass for better thermal performance in the absence of any significant thermal mass on the second story

Windows inset 11” from exterior wall plane to reduce heat loss due to “wind washing”

Only enough operable windows for adequate ventilation (fixed windows have a much higher Energy Star rating than identical windows that are operable)


Second Floor Bedroom / Bathroom

            ERV supply vent (bedroom) and return vent (bathroom)

Corrugated roofing for bathroom wall cladding (long-lasting and recyclable end life)

            Recycled wall cabinet (Habistore)

            1.2 GPF toilet

Unfinished projects

Custom stairway and railing system from rough sawmill lumber:  stair steps from hackberry; balusters from hackberry and red oak, railings from red oak

Interior casework (baseboards, trim around doors and windows, etc.) from rough sawmill red oak

Once the interior is finished, a certified consultant using a blower door tester will ascertain the tightness of the house – a major criterion for either a HERS rating (Home Energy Rating System) or NAHB rating (National Association of Home Builders) that we will seek.

ACKNOWLEDGMENT

We will be forever indebted to the government of Collinsville, IL, particularly the Building Director and his staff for their forbearance during nearly a decade of construction.  If the folks at city hall had not taken genuine “ownership” for the town's first "green" project, it would never have been built.

RECOGNITION 

At Collinsville's 2022 Awards Night, the local chapter of the Cool Cities Committee recognized our project with its "Cool Cities Sustainability Award".  (The nationwide network of Cool Cities Committees was birthed by the Sierra Club.  As ambassadors for sustainability, the club's members serve as advisors to the City Council as well as to civic committees, schools, organizations and citizens.)

Tuesday, July 12, 2022

Design - Sustainability Inventory - Part I: Non-Living Spaces

 

Click on picture to enlarge for better viewing
By now, our 8-year journey to energy independence has been documented with nearly 150 individual blog posts.  For those who may be curious about our project but not enough to wade through myriad posts, perhaps a "30,000 foot view" will suffice even if it takes this post and one more to do justice to the story.

This report posts during the first summer after taking mid-winter occupancy.


UNIQUE FEATURES - OVERVIEW

 Project located in Collinsville, IL on a south-facing slope nestled           in the Mississippi River bluffs opposite St Louis, MO             

         Grid-tied and breaking even with the utility company

        Entirely passive solar; no conventional HVAC

        Sustainability-centric from preliminary sketches to occupancy

        ADA compliant

(The following outline sometimes dwells on these “unique features” but, for most part, they are woven into the larger narrative.


EXTERIOR FEATURES

House

Rectangular-shaped house with its long profile facing “solar” south but canted slightly westward to catch more afternoon winter sunshine

Square and rectangular configurations are the most energy efficient because they minimize exterior wall surface,

They also require fewer building materials and therefore minimize embodied energy for manufacturing and shipping of materials; fewer materials also lowers construction costs

Of note:   the amount of earth sheltering, the conduits for the AGS system and the
PV array  (click on picture to enlarge it)
          
            Earth sheltering on three sides of the house; the grade in back
           of the house is 12' higher than in front, creating the                               thermal mass described below under "Annualized GeoSolar                System"

Exterior walls supported by custom trusses built from lumber salvaged from tear-downs; roof/ceiling supported by "store-bought" trusses

        House insulated with rice hulls:  15" thick (R-45) in                    exterior walls, 18" thick (R-54) in cathedral ceilings         

        The joints between individual roof and wall sheathing                panels and joints between roof and walls are taped to                eliminate air infiltration; all sheathing is plywood rather            than OSB (both products may utilize resins containing                     formaldehyde but plywood has less)

All windows (except one small east window) face south which maximizes winter solar gain; having none facing north or west precludes penetration of north and west winds in winter and unwanted morning and afternoon sunshine in summer

Windows all have overhangs sized to minimize solar gain during warm months while allowing maximum gain during cool months; mid-summer shading by the overhangs for both stories is apparent in the picture above, so much so in fact that the exterior wall looks bluish instead of white

Front entrance and garage doors are shielded by the house from winter winds

Screened porch (yet to be finished) is extra tall for better ventilation; Energy Star ceiling fan; 3' wide soffits (eves) for more shade and better rain diversion

Light-colored steel siding, roofing and soffits

Steel has at least a 60-year life expectancy under normal circumstances; more hail resistant than petroleum-based siding and roofing

          100% recyclable end-life

Smooth, white siding is highly reflective, thus minimizing heat gain during warm months; light gray roof only slightly less reflective than the white walls        

Cool roof design:  A 3½” space exists between the first layer of sheathing (that which lies above the insulation) and a second layer of sheathing (to which the metal roofing attaches) that creates a “mini-attic” through which air passively flows from the soffit vents upward to ridge vents, keeping the roof cooler in summer

Rain Handler system replaces conventional gutters except over traffic areas; converts sheet water from the roof back into raindrops that nourish nearby native vegetation without causing soil erosion

Grounds

Four rain gardens slow runoff and keep it on site until it can soak down to the water table and leave in a purified state as opposed to running on grade and carrying noxious contaminants (from air pollution and from herbicides, pesticides or fertilizers) to neighbors’ or public property and, in our case, to the lake across the street

Rain gardens as well as other landscaping are or will be populated by native plants which require no energy-dense artificial fertilizers or soil amendments and, after the first growing season, require no watering

Shelter belt of native eastern red cedars shielding house from winter winds planted years ago as bare-rooted seedlings; cedars also provide excellent habitat for wildlife – four-legged, flying and creepy-crawling

Photovoltaic array sized to break even with the utility company (“reverse metering”); energy cost limited to natural gas for water heating, clothes drying and cooking

Annualized Geo-Solar System (AGS)

AGS utilizes the energy from the summer sun, supplemented by sunshine through the windows in winter to condition the house year-round in the absence of conventional HVAC

AGS comprises three components

Solar collector (fenced-in depressed area in front of the house) to harvest heat from the sun during warm months

Conduits (4” pipes) slanting upward from the collector to a solar chimney behind the house distributing heat from the solar collector to the earth under and behind the house; design still in flux at the time of this writing -- (see second thoughts on solar collection design)

Insulation/watershed umbrella that extends outward from the house below grade +/-20’ in all directions, hence enlarging the amount of dry and insulated thermal mass available for heat storage beyond just that below the floor

Umbrella lays 12" - 30" below grade and consists of several layers of 6 mil plastic sheeting and a layer of foam board insulation overlaid by a physical barrier of recycled carpet

Heat during cool months comes from that stored in the thermal mass during the summer moving passively into the living space (heat seeks cold); additional heat comes from sunshine through the south-facing windows during winter; conventional heating is unnecessary

During warm months, the heat lost from the thermal mass during the winter is replenished by (a) heat from the AGS solar collector and (b) by heat absorbed into the thermal mass from the living space; conventional AC is unnecessary

Target temperatures for the living space toggle between lower-to-mid-70s (winter) to high 70s - lower 80s (summer), although a good guess is that it will take the heat from at least two summer seasons to overcome the ancient cold exposed by excavation into the hillside (at our latitude, the legacy year-round soil temperature at the depth of 10 ft is 60 degrees)

The house floor (concrete) temperature on our early March move-in day was 60 degrees measured at the base of the concrete north wall; it had risen slowly to 79 degrees by the time of this writing in mid-summer

(The comfort level in an earth sheltered dwelling is a function of a phenomenon called Mean Radiant Temperature.  For an understanding of this important concept, click on the first post at the top of the left column under the heading “Understanding Our Project")


UTILITARIAN SPACES

Garage and Airlock

Garage has super-insulated walls and ceiling; the floor is insulated by the underlying insulation/watershed umbrella; the temperature in the garage was 80 degrees at the time of this writing, up from the upper 60s during the winter

Small area of garage wall is intentionally left uninsulated to create a storage area for fruits and vegetables during cold months (a mini-iteration of the old fashion root cellar)

Wall cabinets in the garage are a Facebook Marketplace finds

The main door of the house leads to a circumscribed space called the “airlock”, essentially a semi-conditioned breezeway that modulates outside air rushing in when the front door is opened – warming it in winter and cooling it in summer – before the outside air can follow into the living space through a secondary door

All four doors leading in and out of the airlock are self-closing so as not to be left open unintentionally 

Vertical Basement

The back (north) concrete wall, 60’ long and 12’ tall, by conducting heat in and out of the soil behind it, is critical for conditioning the house

The distance between the concrete wall and the stick-built wall separating the basement from the living quarters is 5' which provides space for storage shelves 2' deep leaving 3' for wheelchair accessibility

The insulation/watershed umbrella at the top of the wall shields the soil under it from surface water penetration while the insulation traps and holds heat

All but the top foot or so of the wall is backed by the soil under the insulation/watershed umbrella that will gradually become drier and, instead of its legacy temperature of 60 degrees, will maintain temperatures in the 70s 

Lack of insulation on either side of the wall under the umbrella allows heat to pass freely through the wall – from the thermal mass inward during cool months and outward into the thermal mass during warm months

The continuous row of vents near the top and bottom of the tall stick-built wall (that divides the vertical basement from the living space) are critical for allowing room air to reach the wall 

During warm months, three box fans equidistantly suspended from the ceiling  and directed downward can be used to transfer heat to the concrete wall by pulling (warm) air through the top vents and pushing it downward past the concrete wall and out through the bottom vents

Combination GFCI / AFCI circuit breakers in the service panel eliminate the need for individual GFCI / AFCI receptacles at the point of use in the living space

Free-standing (not attached to a conventional HVAC unit) Energy Recovery Ventilator supplies fresh, temperature-and-humidity-moderated outside air without which our airtight house would soon fill with stale and unhealthy air

Home run (as opposed to branching) water supply system using PEX (polyethylene) tubing and a central manifold; the PEX lies below the floor and was shielded from damage while pouring the concrete by running it inside of 1 ½” PVC piping; the PVC also makes it possible to use an original PEX line to pull a replacement line in the unlikely case of a water leak; PEX for supply lines is "greener" than copper lines initially and because it has an indefinite life span

Energy Star tankless (“on-demand”) water heater that heats water once as it is used; more energy efficient than tank types that heat the same water over and over, especially during periods of low or no usage

“Water Cop” system to prevent flooding in the living spaces due to plumbing failures 

___________________                        

The next post covers the living areas of the house.

Thursday, May 26, 2022

Construction - Drywalling, Tiling and Painting

By the summer of 2021, our construction schedule began to take on new priorities.  My arthritic hip was seriously interfering with my effectiveness and we were reluctant to ask for more help from family and friend volunteers.  And I wanted to recuperate from hip-replacement surgery in our new handicap accessible ADA-compliant house rather than in our  one hundred year old residence, a house that gives new meaning to steep and narrow stairways.  So, for the sake of time and wear and tear on me and the volunteers, we decided to pay for more hourly help and subcontract such jobs as drywall taping, painting and tile work.

Friend Myron spraying the ceiling; note the
ceiling grid created by 1 x 6 MDF boards
The creative, design-on-the-fly, one-off thought and effort that has gone into the house over the past 7 years is now behind us.  Finding experienced tradespeople was easy because the interior finishing is essentially the same as for conventional construction.

As discussed in a previous post, the concrete floor was polished and stained as the first step in finishing the interior.  To protect it from drywall mud and paint splatters, we immediately covered it with resin paper and large tarps.  

(Reminder:  Click on any photo to enlarge it for better viewing.)

Drywall Taping and Ceiling Painting

The drywall finishers
Well before the time of this writing (March, 2022), professional drywall finishers had "mudded" the walls and professional painters had done an exceptional job with three coats. The ceilings had previously been finished with a grid pattern of 1 x 6 MDF boards fastened to the ceiling trusses with 3" construction screws.  They were added to secure the drywall under the load of the rice hull insulation which has roughly three time the weight of cellulose.  And they add interesting esthetics while eliminating the need for taping.  In advance of the tapers and painters, the ceilings for both floors were spray-painted by our neighbor, Myron, with a semi-gloss white as the topcoat (instead of the more common flat or eggshell) in order to reflect more of the sun's energy coming through the windows
Scaffold removed -- a major watershed!
in cold months.  

Drywall Taping and More Painting

After the ceiling was done, the second floor temporary floors that served as scaffolding could finally be removed and the drywall hung on the wall next to where they had been.  Finally, we could enjoy for the first time the openness over the living room and master bedroom and the unobstructed view from below of the second story windows and the catwalk in front of them.  It was then time to call in the drywall finishers for taping most of the house in one full swoop -- the exception being the airlock (entryway), vertical basement (storage and utility area) and the garage, which was done a few weeks later.  

Dorothy and Sue laying resin paper to protect
 the stained concrete which is visible in the middle
(viewed from the second story catwalk)

Through the Better Business Bureau we were able to find a local painting contractor staffed mostly by his extended family with high standards for integrity and workmanship. That they were able to start work immediately meant that we suddenly had to chose wall colors that we had only casually been thinking about.  

As soon as the painters were finished with the first phase, the contractor who polished and stained the concrete floor returned for the final buffing.  The painters returned for phase two after the drywall in the airlock, vertical basement and garage was mudded.

Tile Work

Retrieving one set of repurposed
cabinets found on Facebook

The polished and stained concrete floors and the composite flooring for the second floor (discussed in a recent posteliminated the need for ceramic or porcelain floor tile except in the walk-in shower stall, the tub surround in the guest bathroom and the front entry floor.  Despite having an industrial strength tile saw, we decided in the interest of time to buy the materials and hire professionals to do the work. 

Odds and Ends Finishes

The painters departure set the stage for a myriad of odd jobs that had to be done before move-in (which finally happened the first week of March). During the week, I would peck away on them as much as my hip problem allowed then family and friends descended on Sundays to make a huge difference.  Interior doors were hung.  Closets and the pantry were outfitted with shelves, clothes rods, etc.  Serious storage shelves for the vertical basement were made from long recycled pallets. A convenient garment station for the airlock was designed, built and installed by Myron.  The energy-recover-ventilator (ERV), installed a year ago, was balanced by the HVAC contractor.  Openings high on the first floor that allowed warm air at the ceiling to escape to the second floor on its way eventually to be cooled by the concrete north wall of the vertical basement were gentrified with registers. Kitchen and bathroom cabinets (Facebook, Craigslist and Habistore finds) were installed followed by all new Energy Star appliances.  Ceiling fans and light fixtures (all Energy Star) were hung.  And a ridiculous number of wall plates were screwed to place over switches and receptacles.

Finally, we moved my woodworking shop from the free-standing unheated garage next door to the more spacious and conditioned garage attached to the new house. 

Work To Be Done After Move-in

Some of the casework could be done with MDF boards before move-in -- the airlock, garage and master bathroom mostly.  The local Building Inspector approved a conditional occupancy permit without the complete build-out of the interior. This will allow us to live in the house while we do such things as use our stash of sawmill hackberry for the final stairway, use our stash of sawmill red oak for the casework throughout as well as finishing the guest bathroom. His leniency is probably typical of most small town officials; he appreciates the extra time it will take to use the rough lumber and respects my need to take time off from non-essential construction for hip replacement surgery (which occurred the last week of April, meaning no more serious construction work for at least three months).

Stay tuned.