Radiant Tubing before pour

This is all information I knew ahead of time. I had been in houses heated with forced hot air, and I knew how noisy, drafty and dusty they can be, even if the efficiency of using the same ductwork for heating and cooling has great appeal. For this house, polished concrete cried out for radiant, and I’d had good success with ductless air conditioning in past projects, so I went forward with the radiant plan.

Tied down tubing

What I didn’t know, but now do, is that radiant floors require a simply crazy amount of plumbing. It’s not just each little black plastic tube has to get carefully tied down to the mesh before you pour your concrete, or that there is a maximum length of each tube (270 linear feet?), but after all that is done, each and every tube has to come back to a manifold and each zone has to have its own manifold, and each zone needs controls adequate to balance and “tune” the system for proper operation. It felt like miles of plastic tubes where then connected to miles of copper, interspersed with super expensive manifolds and controls that virtually filled the mechanical room.

JC Plumbing Starts Work in Mechanical Room

Pumps and Manifolds everywhere

Those little electric space heaters are looking very efficient right now.

During the early stages of construction, I learned a great deal about concrete finishing and how difficult it is to get an even pour, a good surface and no annoying bits of insulating foam into the mix.

First Round Grinding

Oh and I learned that you can cut grooves into the concrete to try to control where the cracks will show up, but you can only be partially successful. Short story is that no matter what, concrete will crack and there will be unavoidable discolorations and variations in the surface. Good thing that this is part of the appeal for me.  I also learned that the equipment used to polish the concrete for the first six phases weighs 1,000 pounds, requires a generator, and that everyone assumes there will be a freight elevator, since this technique is almost always used for commercial and retail locations.   We solved this issue with an articulated forklift, also known as a “lull”.

Lifting the polisher to the second floor

We had reached the stage in the floor finishing when the fellows from Concrete Solutions of New England were to come back and do the final steps of grinding and coloring. For this process, we had to offer heated, enclosed space, but before the interior partitions were installed so the grinding and polishing machinery could swing freely. Thanks to very highly insulated windows, walls and roof panels, and the little electric space heaters, we were finally ready for them to come back.

Dave grinds around column

Scott grinds and colors 1st floor

Coloring concrete turns out to be more variable than I had guessed. There is a dye chart, and no shortage of pictures that show other concrete floors that have been colored with the dyes in the chart, but when I went to GreenBuild to visit the dye company’s booth I saw a huge variation in samples even when the exact same dye was used. The concrete itself interacts with the dye to affect the final color, and you can really tell until the dye is sprayed on your particular floor what the color will look like. Needless to say, it becomes a very hands-on, eyes-on process to pick the colors.

Dave grinds Master Bath

The grinding and polishing also turns out to be trickier than you might think. Hardness, in particular, seems to affect when the grinder smoothes the surface and when it just scratches it. The first round of grinding uses machinery that weighed a thousand pounds, and we moved it from floor to floor with the articulating forklift. At this stage, they used smaller grinders, maybe weighing only 350 pounds each. One is powered by propane, and the other by electricity. Getting a good looking outcome requires patience, the right equipment and lots of careful attention. The final result, however, is outstanding.

Media room after color and polish

The color purple

Master bedroom after polish and color

My first impulse was to call the mason and ask him to come and build our Tulikivi fireplace, which I was guessing could supply all the heat we’d need.

Tulikivi Soapstone Fireplace

Turns out, of course, that the mortar used in building fireplaces needs heat to set properly, so he won’t come until we’ve heated the building (and don’t need him?)

Temporary heat was clearly called for. Turns out many contractors have access to temporary heating systems which are fueled by propane or kerosene, and in our case both the plumber and Mapletree Building have these systems. It also turns out that these are simple combustion engines, where the combustion waste gases are mixed with the heated air and carry large warnings against indoor use. This building, once roofed and windowed, was too airtight for this kind of equipment.

We did have a post with temporary electric service just down the slope from the house, from which we’d been running extension cords for the power tools. So we decided the simplest method to warm up this four thousand square foot house, full of very cold concrete floors and steel beams, was to plug in a few electric space heaters. The carpenter had one, his assistant had one, I had one and I bought another. Average cost: $39.98, maximum output 1500 watts. We plugged them in and let them run over the weekend, and tried to keep as many of them going as possible during the day, but usually we’d need the circuits for the saws and drills.

Two of the four space heaters heating 4,000 square feet

The weather suddenly turned very cold. The water lines to our trailer froze, despite my efforts to wrap the line in heating tape and bury most of it. There were sub-zero days and at least one morning with temps of minus seven degrees F.

iPhone shows -7 degree outdoor temp compared to indoor

Imagine how delighted we were to discover that this big house, with one thousand square feet of windows, could be kept above fifty degrees by running four or five little electric space heaters at night. Of course, for me, this happy outcome triggered the question: why am I spending forty thousand dollars on a propane fired radiant floor heating system when I could have done the job with half a dozen fifty-dollar space heaters?

Just one of the radiant floor manifolds

The blower fills the doorway

They even used the digital readouts to confirm the amount of air the blower had to add to the building to keep the pressure up to the accepted standard.

Digital readouts measure air loss/minute

Even before we had a chance to fill the gaps we knew about, and without having sealed the garage door, the house could get up to pressure and hold it.

Dave the carpenter feels the flow

Apparently, some older houses leak so much air that they can never attain the target pressure, so we were off to a good start.

Next the smoke machine was set up outside, next to the blower door, and fired up.

A fog machine provides the smoke

Nontoxic smoke was blown into the building and we wandered around the exterior looking for telltale wisps of smoke to show where the leaks were. There were distressingly many of them, but most could be easily addressed with the foam kit. Some, however, were out of easy reach, since they were along the roof line and others we just didn’t get to before the CSG guys had to move along to their next appointment.

We realized we needed to do more smoke testing when we had more time and when we had access to the elevated platform from which to foam the wall-roof intersections. For our purposes, we think all we need is a smoke machine and a standard box fan, rather than the expensive blower door apparatus.

We went out there the day before yesterday and it was about well really cold. The contractors were all working very hard inside though despite the lack of heat. We went through the house and looked at how everything was going to be put together. I liked the fact that it will be wide open in the middle and seems to be filled with light.

That does seem to be a theme that apparently has both aesthetic and sustainable design advantages; Light everywhere. Plus all the rooms have to have more than one light source. The appearance of the house was also somewhat deceiving because form the outside, it looks like it would be cold and dark inside but upon entrance it is very lit up and warmer than the outside despite the lack of heat. Looks like a good spot to fish too.

There was also the excitement of watching a very large backhoe get pulled out of the mud. It had been quite freezing for the previous couple of days so they thought it would be safe to drive this large piece of machinery over the frozen swamp. It turned out not to be quite cold enough and the thing sank almost to the top of the five foot high wheels. No problem though, they just used another crane like machine to pull the thing out of the half frozen mud, took about 15 minutes.

Good to see it all in person and I would hijack the house if I weren’t so urbanely inclined

We knew from early on that the weakness of the insulated steel panel system was going to be the joints, and we have been relying on guidance from a super-insulated  house expert and foam guru, Henri Fennell from Building Envelope Solutions Inc (http://www.foam-tech.com/) who specializes in spray foam solutions to the kinds of problems we anticipate.

The spray foam seals the joint

One of the tricks is that for the two chemical foam to work properly, the foam itself needs to be warm, and we have passed the time of year when warmth can be counted on.  But it turns out that if we keep the foam kit warm in the cab of the pickup truck, we can use it even when the house itself isn’t warm.  We did discover,  however, that the expanding closed cell foam can get out of hand when it is windy.

Foam expands and it's hard to clean

We needed little cans for the small cracks, like between the window frame and the “buck” into which the windows fit, and big foam for the large gaps.  We buy the kits from Energy Federation Incorporated, which has an office reasonably nearby, in Worcester Mass.  (http://www.efi.org/index.html)

Dave foams corner from lift

Some of the foam is best applied from the inside, but other spots can only be reached from the articulating forklift platform.  When its done, it looks like big yellow fungus is growing out of the building’s cracks.

Next Tuesday, we will be getting a smoke test to find out where the missing foam needs to go.  Conservation Services Group (http://www.csgrp.com/), (whose offices are right next door to Energy Federation) will be sending over a team with a blower door fan and a fog machine and we’ll fill the house with smoke, then pressurize the interior, and walk around looking for smoke pouring out of the gaps we missed the first time around.  We’ll have to perform a real blower door test again once the house is more complete, but this time we will focus on the gaps that we won’t easily be able to fill after the building trim is installed.  This should be great fun.

In the sketchup (www.sketchup.google.com/) model I built of this house, there was a view that looked like this:

The Model

I have been working in imaginary computer space for years, but suddenly, the other day, the real world reached out to meet my imagination:

Real World Steel House

In this picture, the roof and most of the windows are missing, but it looks so very close to what I wanted.  I love it.

The panel attachment process has taken longer than I thought, but there have also been days when the advantages of prefab construction really are impressive.  The theory behind much of this design was site specific design using elements manufactured in factories and assembled on site.  The best discussion of the advantages of this approach was in a book written by two very charming brothers who share an architectural practice, a house and book-writing tasks, the Andersen brothers .  I met them when I was visiting EcoSteel in Utah, and had a great time later talking with the two Andersons in San Francisco.  They had just written a book that I thoroughly enjoyed called “Prefab Prototypes” .  The short story is that there has been a continuing trend from making all the building components on site, such as the windows and doors, to buying the parts pre-made and assembling them on site instead.   My goal here was to take this a little further than most house building but not so far as the prefabricated house builders who build the whole home offsite and drop it on the land nearly complete.

For us the walls and roof came on trucks in plastic wrapped bundles:

Panels Come in Bundles

They are labeled (one of my jobs) and unbundled and laid on the ground:

Chris looks up at the house

The walls mostly go up first, but the roof panels are a very exciting part of the enclosure process, especially when the weather forecast is for snow.  The first roofing day, we got only one panel up, mostly due to some logistic issues with fasteners.  But on last Saturday, they got fourteen roof panels up in one day – a great accomplishment.

Crane Lifts Roof Panel Up

These panels are five inches thick and provide a waterproof R-41 insulating roof system.  They are a mixture of tongue in groove connection with a standing seam metal roof top.

Roof Panel Profile

They have to be trimmed at the tops to fit around the columns, and the plastic wrapping is removed after the seaming maching crimps the overlapping joints.

Roof Panels are notched around walls and columns

Some of these past few days have been a little cold, and no one wants to walk along icy steel beams, but luckily, each day the sun came out enough for the workers to get up on the roof and fasten these great panels into place.

Steve, Chris and Romolo work on the roof panels

Romolo on the first roof panel up

Steve Working in the morning sun

There are still some little wall panels that fit in between the lower and upper roofs, and some of the windows still need to be inserted into their frames and into the openings in the steel walls, but we are getting so very close to being able to foam the joints and seal the building up.  That will make it possible to get going on the electrical, the heat and the plumbing.

First I found a company in Park City Utah that specialized in steel panel construction and I had many interesting conversations with them and one of their partner architects Anderson Anderson .  Eventually, I decided that they were too far away and a little less flexible than I wanted for my house design, so I decided I’d have to cobble together my own team here in Massachusetts.

I started with Centria  – they have a beautiful panel line, and they had recently been certified as cradle to cradle by MBDC (Bill McDonough’s company ), but they turned out not to be set up for small projects like this.  They prefer hundreds of thousands of square feet per order, and when I finally got a price from them, it was three times as high as the sales guy had predicted.

There are several panel making companies, and a few that specialize in the very thick panels that I needed to fulfill my super-insulated goals.  These panels are usually used for food storage or freezer buildings, and are not detailed for aesthetics.  This has turned out to be one of the major design challenges I faced: how to make a building look and feel residential while using very industrial materials and trim.

For a while I was stuck.  Centria offered the best look, but was very pricey and didn’t make the very thick panels.  Some of the other companies made thick panels but only offered them in finishes that I was afraid would make the building look like a self storage facility.  In the end, I found a company that offered what I wanted: a five inch thick wall panel, rated at R-41, with a flat finish and a good choice of colors.  It turns out that Alum Shield, a division of Metecno,  which was recently acquired by Kingspan, was my solution.   These steel panel companies are huge, and very international.  My order, of course, was out of the ordinary and caused no end of problems down in Florida.  I wanted a flat finish on a freezer building panel and I wanted a custom color and then, because they told me that the flat finish might cause problems, so I ordered heavier gauge steel for the exterior skin.  They ordered the wrong gauge steel, then they lost the barrel of paint, then, I don’t know what happened then, but order arrived six weeks late.  But it did arrive!

Unloading Steel Panels

One of the issues that affected the cost and time required for assembly was that when steel panel buildings are typically erected, they put all the panels up first and cut holes for the windows and doors later.  A freezer building might have a couple of doors and no windows, so this makes sense.  But my house design calls for fully 25% of the wall area to be doors and windows, so cutting out and throwing away 1,000 square feet of panels would be a huge waste of  material and money.  As a result, we needed to change the standard process of attaching panels and cut the panels before they got attached.  This meant pre-planning and carefully numbering all the panels before getting started.

Numbered Panels

We designed the width and placement of the windows to work on the grid line created by the panel seams, which, when you allow for caulk, is 42 and one eighth inches.  Needless to say, we had to tinker with this as the framing went up.

Checking Layout with Sample Panel

With a game plan and field measurements, we were finally ready to unwrap the presents from Florida.

Cutting Bundles Open

Each window or door opening requires a short panel below, inbetween and above.  Erection Specialists bought a brand new specialized saw just for this job, and they were eager to put it to work.  It is an cross between a circular saw and a chain saw, and the CD-ROM that came with it shows it is designed specifically for cutting steel panels like these.

Putting the new saw to work

The first day didn’t go as well as planned.  First, there was a problem with the screws (self tapping instead of self drilling), then a problem with the drill bit, then the wrong drill driver.  And finally, the new saw busted.  At the end of that day, all we had managed to accomplish was to affix one panel.  And that one panel was tied to the structure with rope.

Mixing Old Technology with New

Fortunately, the next day went much better.  We had the right screws the right drills and a replacement saw, which had been shipped overnight from somewhere far away.  Dave Keane, master carpenter and president of “By Others” construction worked with his assistant Tim to put the windows into the openings as the walls went up.  By the end of the second day, we had one wall, untrimmed, but looking fantastic.  For the very first time, we got to see how the wall panels looked, in place, and with the windows.

First Wall w/ Windows

Check it out here.

The best way to reduce heat loss when designing a wall would be to eliminate the windows entirely. This is why cold storage buildings don’t have any. And my wall system uses freezer building wall panels which offer R-41 whole wall insulation performance which give me a good start on the super insulated plan. My design, on the other hand, is inspired by more than reducing heat loss, and windows are key to some other goals. My site is on the Sudbury River, (during spring floods, the house itself will be almost surrounded by the Sudbury River), so the views and the setting are spectacular and designing the windows to allow these views to be appreciated from inside was a key driver of the design. In addition, proper window design allows natural light to penetrate into the house so that electrical lighting use can be minimized during daylight hours, which contributes to energy efficiency as well as psychological well-being. Lastly, south-facing windows can capture winter sun, and the solar gain can lower heating costs in winter.

So, minimize windows to prevent heat loss, add windows for daylighting, orient windows to capture solar gain in winter, shield windows from solar gain in summer, and orient windows to connect to nature. That’s just to get started.

I thought that windows could be compared to each other based on how much heat they lose. My walls and are five inches of high density foam sandwiched between steel, and they are rated at R-41. R-1, in contrast, is a measure of heat loss based on a single pane window, so there is a huge range between the best wall and even the best window in terms of insulation. It turns out that there are other measures that matter with windows as well. SHGC, which stands for Solar Heat Gain Coefficient, is another. This relates to how much usable heat from sunlight you can get through your windows in the winter; the higher the number, the more solar gain the window allows. In climates without any cooling season (very cold climates) the more solar gain the better, but in climates like New England where we have both heating and cooling needs, you need to pick a mid-point in the solar gain range so that the winter sun brings in heat but you don’t have too much over-heating in the summer. In very hot climates, you need to pay a lot of attention to reflectivity of window in order to manage the unwanted solar gain and moderate air conditioning costs.

The other important factor I needed to consider was durability. This is a guiding theme of this whole house design; the longer each part lasts, the more sustainable the house will be. Window frames can be made out of wood, metal or fiberglass, or some combination. Wood and fiberglass both conduct heat less well than any kind of metal, so the best insulating windows are not typically aluminum or steel. I found the most energy efficient windows are made in cold climates, naturally, and the best fiberglass frames are all made in Canada. The big window companies are all adding high performance windows to their offering, but I ended up with Alpen, out of Colorado (http://www.alpeninc.com/) which specializes in using heat mirror films in conjunction with double pane windows and pultruded fiberglass frames from Duxton in Canada (http://www.duxtonwindows.com/). I’d first heard about Alpen on Environmental Building News website (http://www.buildinggreen.com/) but since I ordered the windows, the company has been acquired by a California company called Serious Materials, (http://www.seriousmaterials.com/), which looks like a very interesting company.

These windows range in R-Value from nearly 8 to just above 4, depending on how operable and how much solar gain we want to allow. Thus, the fixed window, north or west facing windows are the highest insulating, while the glass doors and south facing windows are much lower in terms of insulating quality. This house is going to have lots of glass (nearly 25% of the wall area is glass) which I’m hoping will make it very light and wonderfully connected to the natural surroundings, but which loses me some LEED points and will, no doubt, bleed heat out on the dark winter nights at a much faster pace than if I’d gone minimal on the glazing.