Exterior Foam Insulation

Just to backtrack a bit…For the exterior insulation, we used two two-inch sheets of Polyiso held to the sheathing with 5/4 by 4″ poplar furring strips and six-and-a-half-inch Fastenmaster Headlok screws.  The one-by-fours cost us about 25 cents per linear foot.   That seems like a decent price, particularly since they’re a full 1″ thick (actually the thickness varied a bit, but was generally about 1 1/8″, so we planed them down to 1″).


We’re using Polyiso because it has a higher R-value than EPS (which is what the ICFs are made of) or XPS (which is what we added to the outside of the ICF foundation).  Polyiso has an R-value of just over 13 for 2″.  Tuff-R and Super Tuff-R are Dow’s Polyiso panels.  Super Tuff-R has a more durable facing than does Tuff-R.  R-Max Thermasheath 3 is another brand of Polyiso that Home Depot stocks, and appears to be less expensive than the Dow products.  The R-value is the same for all three products (i.e. R-Max reports 13.1 and Tuff-R reports 13).

Home Depot in our area stocks R-Max.  It is $30.25/sheet off the shelf and on the Interweb.  I went to the local store and told them I needed 150 sheets.  They put it through their “bid room” and came back with a quote of $26.73/sheet, which is an 11.6% discount.  So the total cost ended up at just over $4,000.

The Framing Continues

By September 5th, most of the necessary framing materials had been purchased and assembled, and the framers started working up from the first floor decking.

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The longest wait was for the trusses that will be used for the roof, porch, pents, and the second floor.  Unlike the first floor (where we used Flack Jacket I-Joists), we’re using floor trusses for the second floor because we’re figuring that they will make it easier (than I-Joists) to route the pluming, the heat pump lines, and the ERV ducting.  The following photo shows the floor trusses, along with a bit of post and beam work created by the builder, Hugh Lofting Timber Framing, that will define the division between the kitchen and dining area (and also the fir beams that will be above the kitchen/living area):

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As shown in the photos, a number of the key principals of “advanced framing” are being applied to the shell structure; framing 24″ on center;  joists, studs and trusses will be “stacked” (i.e. line up); single headers; single top plates, and two-stud corners.  This is new to everyone involved in the project.  So the pace was slowed down to ensure that the essential details were correct.  We lost count on the number of tubes of polyurethane caulk used.

We’re using Huber’s Zip System for the exterior sheathing, which  think is pretty common these days.  But since we are framing at 24″ on center, and I wanted to ensure a bit extra structural support, I opted for the half inch Zip for the walls, rather than the more common 7/16″.  That decision resulted in an upcharge of approximately $1.30 per sheet ($21.75 vs $20.45).  Basically, the entire shell will be covered with the Zip sheathing.  The 1/2″ product will be installed on all vertical exterior walls and the second floor ceiling.  A 5/8″ version of the product will be used for the roof.  Of course, all of the seams will be sealed with the Zip tape, at about $26 per roll.  The estimated use is one roll for every 7.5 panels.

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As the photo indicates, when initially completed, the shell will only have one opening, which will be for the front door (the basement windows and the door in the Bilco well will also be installed).  Once the blower door test passes the Passive House standard of .6 ACH @ 50 pascals, the windows and the two remaining doors will be installed, and the shell will be retested.

By COB on September 11th, the framers were closing in on completion of the second floor.  Here’s a couple of photos from earlier in the day:

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Selecting the Windows

At the outset of this project, I was very confident that I would put Serious Windows in the house.  I had read a lot about them, and it looked like they were a viable option (actually the only option) that would allow me to purchase windows from a domestic manufacturer. [For those of you who don’t already know, Serious sold the window business back to Alpen High Performance Products in the fall of 2012.]

Serious/Alpen Windows are different than the typical European Passive House windows in a number of ways.  First, the frames are made of fiberglass rather than the U-PVC or wood that seems to be typical in the imported windows.  Second, rather than using three panes of glass, Serious/Alpen uses two panes separated by a suspended film.  Third, their casement-style window opens outward (it is my understanding that the European windows generally open inward).  And finally, they lack the “tilt” part of the “tilt-turn” feature that is common in Europe.  This feature allows you to open the [casement] window as you would expect a casement window to operate.  But it also allows you to tilt the top of the window open in those instances where you might want to vent air unobtrusively.

For our project, I focused on the 725 series window, which is the mid-point in the Serious/Alpen line.  According to the Serious/Alpen data sheet, the 725 series casement window with high solar heat gain offers a .18 U-Factor (5.6 R-Value), .37 Solar Heat Gain Coefficient (SHGC), and .48 visible light transmission (VT) [725-datasheet-20130129]

Armed with that information, I reached out to Alpen in December 2012 for a quote, which came back at $19,785.97, or about $77 per square foot (freight not included).

Throughout 2012, I had read several articles/blogs about other Passive Houses that had used Intus windows.  And at about the time I received the Alpen quote, I read an article about a relatively new (to the U.S.) window company called Zola that piqued my interest.  So I decided that it would be worthwhile to get a quote from both.  I have to admit that I didn’t have high expectations that they could compete with Serious/Alpen when it came to price (simply because Alpen is a domestic manufacturer).  But I did like the tilt-turn feature of the European windows, as well as what appeared to be the slightly better performance of the Intus windows.

I never heard back from Zola.  It’s one of those things that has happened repeatedly over the years (with projects on my current home).  I reach out to a contractor to obtain a quote or a price on a specific job/product, and either I never receive a call-back, or I receive a call-back with a promise of follow-up, and the contractor then disappears; never to be heard from again. But I digress…

Fortunately, I did get a quote from Intus.  The Intus window that seemed to make the most sense for me was their Eforte “Passive House” line. Unlike the Alpen window, the Intus Eforte uses a U-PVC frame and triple glazing.  The frame has an R-Value of 5.99.  The glazing has a U-Value of .088.  The SHGT is .494, and the VT is .709.  In short, the performance trumped that of the Serious/Alpen windows.  But the most surprising thing about the quote was that the delivered cost of the Intus windows as just under $50 per square foot; a significant savings over Alpen.

After a couple of visits to the Intus office in Washington D.C. to speak with their representatives and examine the window, and after giving it some thought, I placed an order in mid April 2013. It was a difficult choice.  But I just couldn’t justify the additional cost for the Serious/Alpen windows.

To be honest, I do have a couple of slight concerns.  As I previously mentioned, the windows open inward.  This could cause a problem, particularly over the kitchen sink where the faucet is sticking up.  But fortunately, in my situation, the window over the sink is a double, and if the faucet is placed properly that shouldn’t be a problem. I also suspect that the tilt feature will be used most of the time, and that obviously would not create the same issue.

There’s also a potential issue in that shades/blinds may be difficult to use when the windows are open (either tilt or turn).  But I don’t really anticipate that we will be using the windows in that manner (i.e. open with shades drawn).  And if it turns out that I’m wrong, I’m confident that we’ll find an alternative.  Things do have a way of working out.

As of this moment, the windows are scheduled to hit the Baltimore port in late July.  That’s pretty much on schedule (Intus estimated a nine to 14 week lead time) and should work out well, timing-wise, with our project.

[I should note that, when I received my first quote from Intus (in December 2012), there was no shipping charge.  But by the time I placed the order (in April 2013), they had instituted a $4,000 shipping fee on all orders of less than $25,000.  Fortunately, they agreed to reduce that charge to $500 for my order because I had obtained my first quote prior to the change in policy and because I agreed to allow them to combine my shipment with another shipment.]

Putting the Project Out to Bid – Part 2

Looking at the results from the initial bid process, it was clearly evident that the total cost of the project was beyond what I was willing to spend, and frankly beyond what I thought made sense.  So with that in mind, I approached the two highest-bidding builders with a proposal; would they be open to enter into an agreement where I act as general contractor for the overall project, but engage them to build the shell of the house?  More specifically, I would work directly with subcontractors to do the excavation, septic, well, plumbing, electric, HVAC, drywall, insulation, flooring, paint, etc.  And they (the builder) would handle the foundation, framing (interior and exterior), siding, roofing, and concrete flatwork.  There would be some areas of overlap.  For instance, I would purchase the windows and exterior doors, and the builder would handle their installation.

Doing this would allow me to save in two ways.  First, on all work that I directly contracted, I would save an amount equal to the builder’s profit margin.  And second, depending on how tight the budget was (and how much time I had) I could do some of the work myself. Things I had in mind were finishing the second full bath, installing the wood floors, installing the interior trim, installing the kitchen cabinets, building the kitchen island, installing the attic insulation, and painting the interior top coats in every room.  My goal was to get the total cost of the project (house and garage) as close to $400,000 as possible.

Both builders agreed to the potential arrangement, and submitted the following bids:

Download (PDF, 54KB)

In the end, the bottom line price had little to do with my decision.  My choice, when it came down to it, was to go with a younger builder who seemed to pay significant attention to detail (which I consider to be a positive attribute) and an older builder who has been in business for decades and had an interest in the Passive House concept prior to meeting me.  It wasn’t easy; in fact it was almost the flip of a coin.  Either of the bids, when put together with the rest of the project costs (which I pay directly to sub-contractors), appeared to allow me to get within reasonable range of my $400,000 “goal” for the entire project.  More specifically, I concluded that, depending on the quality of finishes that my wife and I decided on, the cost to construct the house and garage would be somewhere between $420,000 and $450,000.  That certainly wasn’t as “inexpensive” as I had initially hoped.  But it was a price I was willing to pay to see the project through.  So I pushed forward, and decided to work with Hugh Lofting Timber Framing out of West Grove PA.  Hugh’s been in business since the 70s, and although his business centers on timber frame construction, he has a deep interest in energy efficient homes, was finishing up a “Larson Truss” residence that was turning out beautifully, and attended Passive House training.  He also has a personality that I felt meshed with mine, and a character that I felt I could trust.



Putting the Project Out to Bid

In December, 2012, my architect had pretty much finished the house plans, so I was anxious to put the project out to bid.  I was undecided as to whether I wanted to be my own general contractor, and frankly I didn’t know whether I could afford to hire a builder to do the complete project.  But after giving it some thought, I decided that it would be best to start with the latter in mind.  So I started looking for builders.

I found three builders by going down to one of the local building suppliers that I frequented for materials used at my current house.  I found two other builders via my architect. One was the builder that gave me my first independent cost estimate.  The other was a local timber frame builder who coincidentally had an interest in the Passive House concept.  And I found a sixth builder by jotting down the name from the sign in front of a custom home that was being built a couple of miles from our current home.

I called all six builders, and although only two knew what Passive House was, every one expressed interest in the project.  I followed up by emailing each the plans and spec sheet, and suggested that we meet (individually) to discuss the project further if they still felt they were interested.  Two of the builders never got back to me after reviewing the plans, so I wrote them off.  But the other four followed up with an in person meeting, and all expressed interest. So I sent them the bidding instructions, plans, and specifications, and gave them a month to put their bid together.

As it turned out, only three of the four actually submitted a bid.  Here’s how they came in:

Download (PDF, 62KB)

I had several issues with the low bid.  First, he was the same builder who I paid for an estimate in early 2012, and his bid was now materially higher than his prior estimate.  It seemed to me that there should have been a greater consistency between the two. Second, his bid appeared to have a number of holes in it.  And third, his bid was materially lower than the other two bids.  From my perspective, these three facts indicated that he didn’t really put forth a meaningful effort, and I therefore couldn’t consider his bid reliable.  So I ruled it out.

Having narrowed it down to two contractors, I still had a problem; the cost to have a builder take on the complete project would just cost more than I was willing to spend.  So I fell back to Plan B; I would ask the two builders if they were interested in taking on the project with me acting as the General Contractor for everything other than the construction of the shell of the house…

The Lot – Part 2 – Storm Water Management, etc.

Understanding, and dealing with, the steep slopes issue was only part of the challenge with the lot.  While consulting with the civil engineers, I learned that there were several other issues that needed to be addressed if I wanted to actually build on the land.  Specifically (with the estimated engineering cost to design):

1. A storm water management system and drainage plan had to be designed – $1,145

2. A grading and erosion control plan had to be designed – $1,580

4. As a preliminary step in designing the storm water management system, stormwater infiltration testing had to be conducted – $1,550

In my Pennsylvania township, if you plan to construct a building that is more than 1,000 square feet, you must design and build a storm water management system to handle the water that is certain to run off the roof during a rain.  In addition, the construction plan must include a plan for grading the build site and ensuring that erosion is controlled.  So the civil engineering firm will performed this testing, create the designs, and assist me in obtaining the necessary approvals.

The septic system is a separate but related issue.  It cost about $300 to have the system designed, and will cost another $5,100 to have it installed.  Interestingly (and fortunately), a septic drain field is one of the two easy exceptions to the “you can’t touch the steep slopes” rule.  In my case, that’s exactly where it will go, and approval to put it there does not require an appeal to the planning commission.  FYI – the other exception is a driveway…if there is no other alternative.  Fortunately, I don’t have that problem.

April 30 2012 – Insulated Concrete Forms

Shortly after our visit to Superior Walls, I reached out to a local foundation contractor that is known to have experience with Insulated Concrete Forms.  He provided one more interesting perspective on the foundation issue; another illustration of why the multitude of decisions in a project like this are so difficult to sort out.  He said he’s used ICFs for seven or eight years, and he estimated that using ICFs would result in a cost premium of 10%-15% over conventional poured concrete; certainly do-able in our project.  He said that there are over 40 different brands of ICFs, and that he uses Amvic ICFs.  However, the most interesting part of the conversation was his perspective on Superior Walls.  Not surprisingly (considering that he was talking about his competition), he was very negative on Superior Walls, and expressed concern with regard to their acceptance as a foundation alternative.  He mentioned the thermal break issue.  He had concerns with the lack of footings and what he called the “brittleness” of the wall structure.  And he claimed to have pictures of multiple Superior Wall failures.  At any rate, he said that he’d be happy to provide a quote for ICF and/or poured concrete if we send him a pdf file of the plans.

My architect followed up by sending him the necessary information, and the quote came back at just under $25,500 (ICF Quote).  That was quite a bit more than I had expected.  But there are a few things to keep in mind.

First, as my architect pointed out, unlike the $10,500 estimate for poured concrete, the insulation (generally 5″ of foam) is an integral part of the ICF package, and the interior is ready for drywall.  No framing is necessary.

Second, the quote was for an ICF wall with an 8″ core.  I’ve since been told (although I can’t confirm that it’s true) that 8″ ICF’s are atypical in residential home construction; virtually all residential builds (that use ICF foundations) us ICF’s with a 6″ core.  Having said that, I do know that the up-charge for an 8″ system over a 6″ system in my house is less than $1,800.

Finally, at the time we asked for the quote, we were anticipating a “walk-out” basement.  So the quote included 38′ of “frost wall” (basically it would be along the entire length of the rear of the house), which added some to the cost.  That was not considered in either the Superior Walls quote or the poured concrete estimate.

So, after adjusting for those three items, the difference in cost between poured concrete and ICFs does narrow in a way that is not insignificant.  But ICFs still carry a material premium.


April 24 2012 – A Visit to Superior Walls

In late April 2012, my architect and I attended an open house at Weaver Precast, a manufacturer of Superior Walls.  I had contacted Weaver a couple of weeks prior, to get an estimate for the cost to use Superior Walls as an alternative to traditional poured concrete for the foundation (the house will have a 9′ basement).  Amazingly, they came back with an approximate price of $9,800 for the R 12.5  “Xi” wall system.  The estimate was amazing because it was less than the estimate of $10,500 for poured concrete (without any insulation or waterproofing) that was provided to me by the local builder who put together the formal estimate several weeks earlier.  The price quoted by Weaver was “delivered and installed.”  The excavation and a gravel base leveled to within 1 inch would be on me.  The Weaver crew would then come in, complete the leveling as necessary, and install the walls.  According to Weaver, no waterproofing is necessary.  The estimate was based on the following:

-Two-story farmhouse style single family residence, plus basement
-Basement walls to be 9 feet high
-28′ by 38′ four corner rectangle.  No bump-outs.
-Four basement windows; all less than 4 feet wide

I should also note that the house will be less than 50 miles from the factory.

The Weaver open house was put on for the purpose of introducing the newest Superior Wall system; the R 21.5 Xi+.  I asked for an estimate for that wall also, but they hadn’t yet finalized the pricing.

So at that point, Superior Wall appeared to offer a lot of value for the money.  On the other hand, my architect felt that it presented issues with regard to the thermal envelope.  And then there were the concerns about a foundation wall system that was precast, used no traditional footer system, and was bolted together with sealant between the joints.

My next step was to get an estimate for an Insulated Concrete Form (ICF) foundation, to see how it compared. My architect had some experience with ICFs, and appeared confident that it possessed attributes that would play well into dealing with the thermal bridge issues in our project.

March 16 2012 – The First Independent Cost Estimate

In my earlier post, I said I was hoping for a build cost of about $175 per square foot (for the house and one garage), and I prepared several estimates that seemed to confirm that it might be possible.  But my architect was skeptical for several reasons.  First, he thought that I might be making a mistake in thinking that I could be my own general contractor.  On top of that, he figured that a more realistic figure for a custom house in today’s market was $250/sqft (house only, including a a general contractors profit).  And finally, he thought that a Passive House might be different enough to cause that figure to increase beyond that (and beyond what I was willing to spend).

So given those concerns, in March 2012 he had the plans far enough along, and we agreed that it would be a good idea to get an estimate for the cost to build the house that was being designed (i.e. a Passive House).  To keep it simple, we’d ask for the house only (no garage) and to be conservative we’d have the estimate include the contractors profit.

So we brought in a local builder who was working on an energy efficient housing project in the area to give us the formal estimate.  We met with him, and described our goal.  Similar to our experience with other contractors, he wasn’t particularly informed with regard to the Passive House concept.  Although he appeared to be interested in the possibility of getting the job, he made it clear that he would not provide the estimate for free.  I agreed to that, thinking that I wasn’t ready to put the job out to bid (and depending on his results, might never get there).  I also figured that I was asking for a fair amount of work.

After taking a couple of weeks to pull the information together, the contractor came back with an estimate of just under $280,000.  At first glance, I was thrilled. But upon closer examination, I found that his work was, in short, lacking.  For instance, some items, like “interior millwork” were left as “To Be Determined.”  And other items were obviously (and sometime laughably) low; like $3,010 for kitchen cabinets.  Having recently remodeled my current kitchen, I knew there was no way I could realistically purchase decent kitchen cabinets for that price.

So I bumped up and filled in where necessary.  I increased the kitchen cabinets, added on the cost of a driveway, increased the potential cost of the windows and floors, and added an estimate for the well and septic system, among other things.  By the time I had finished, the total had increased to approximately $339,000.  Subtracting out a 15% contractor’s profit, and I end up at $288,000 for the house, indicating that I should be able to GC the work (house and 1st garage) for less than $350,000 (or $175/sqft).  Maybe my prior estimates were a bit too conservative.  The truth would reveal itself when I actually put the project out to bid.  But in the meantime, I was comfortable with moving forward.


My Initial Cost Estimates.

Back when I started this project (almost two years ago), the budget was the big mystery (and it remained a mystery for at least a-year-and-a-half).  At that time, I was not yet on the Passive House train, but I knew I wanted an exceptionally energy efficient home that was modestly sized (I was figuring about 2,000 square feet based on an off-the-shelf set of plans that I had seen).  I also knew I wanted two garages.  The first, which could be attached or detached, would be about 24′ deep by 32′ wide.  The second, which would be detached, would be about 24′ by 36′ wide, and would house my wood shop.

I’ve been a reader of Fine Homebuilding (FH) for years, and I highly recommend it for anyone who’s thinking of building a new home, or engaging in a major remodel.  As the title implies, the magazine focuses on what might be considered the best in home design and construction.  It’s a continuous source of ideas and inspiration.  For many of the featured projects, FH will post the “stats,” which include the cost per square foot.

Now I’ll admit that there are two problems with this right out of the gate.  The first is that trusting these figures means trusting the source, which we do at our own risk.  The second is that the reader must be conscious of all of the variables that go into that square foot figure.  Is the land included?  How about the garage?  Where is the property located?  How much of the work was performed by the owner, or otherwise “for free” (yes, I know, nothing in this life is truly “free.”)

At any rate, after reading countless articles in FH, and in similar publications like the Journal of Light Construction (JLC) (to which I also subscribe), I just got the sense that $175/sqft (based on the square footage of the house) might be reasonable for the house and one of the two garages in southeast Pennsylvania.  Since I was figuring that the second garage wouldn’t be built until well after the house and first garage were finished, I didn’t include it in my computation.  If I was correct, I’d be able to build the house and first garage for about $350,000.  At the time, I didn’t give much thought to any general contractor’s profit.  So that was a significant flaw in my thinking.  But on the other hand, at about the same time my nephew was toying with the construction of a 3,200 square foot “McMansion” in Michigan with a three car garage and full basement, and he believed that he could build it for somewhere around $100/sqft (acting as his own general contractor).  Since he’s in the trades (he owns his own electrical company), it gave me some comfort that $175 was do-able for me.

Knowing that my estimate was a bit too imprecise, I searched out other sources.  Sites like Build Your Own Home (BYOH) were very helpful.  BYOH has a fair amount of discussion and Q & A on budgeting.  It also has a link to building-cost.net. As the site says, it takes five minutes, and it’s free.  The numbers come from the National Building Cost Manual, which is printed by the Craftsman Book Company.

I also used RS Means.  They publish a great book, called Residential Cost Data, and it’s updated each year.  I purchased last year’s version (2011) on Amazon for about $68.  This book provides the information necessary to do a relatively quick “square foot” estimate or a more details “itemized” estimate.

The main thing I learned from all of this is that, regardless of the method I use to estimate my costs, the old adage “garbage in-garbage out” applies.  In other words, the number that pops out at the end was dependent upon how conservative I was going to be in inputting my data.  In an effort to be conservative, I tried to use numbers on the high side, or, to put it simply, I ” rounded up” when I input the data.  Frankly, that was tough to do when my brain wanted to see the lowest possible number in the end. But I hate surprises, especially when they cost me money.  So I fought the urge and tried to toe the conservative line.

So where did this leave me?  Well, here are the results for the house and both garages (land and general contractor’s profit not included):

The Build Your Own House exercise resulted in an estimate of approximately $398,000.  That put the cost of the house and one garage at about $370,000.

The RS Means Square Foot exercise resulted in an estimate of approximately $414,000 to $450,000, depending on the quality of finishes.  That put the cost of a house and one garage at $380,000 to $410,000.

And the RS Means Detailed Estimate exercise resulted in an estimate of approximately $434,000.  That put the cost of a house and one garage at $392,000.

When sprinkled with a bit of wishful thinking and owner’s bias, those estimates didn’t seem that far off from my original SWAG.  So I felt fairly comfortable that with a bit of cost conscious shopping and budget control, I might be able to hit my $175/sqft target.