Tag Archives: economics

Last rock wool pick up

We had started to frame out the perimeter walls on the second floor, and at the same time insulate them with rock wool.

Well, the time had come to make one last trip to pick up the last batch of rock wool. If I measured and calculated correctly, this last batch should allow us to complete the 2nd floor insulation. I may need another bag for an odd job here or there. But the big task – the insulation of the building envelope – was about to be completed!


This felt like another milestone. The numbers are certainly impressive:

To insulate our building envelope I purchased 194 bundles (or bags) of rock wool.

That took care of the basement and 1st floor2nd floorand attic.






We unpacked, handled, fitted, and installed a total of 2,328 rock wool batts, each measuring 15 ¼ inches wide, 47 inches long and 3 ½ inches in depth (stud depth). At 4.975 square feet per batt, we installed a total of 11,581.80 square feet.

The total material cost added up to $6,348.37, including taxes. That translates into $0.55 per square foot of 3 ½ inch batts, or $0.16 per board foot (one board foot is one inch over one square foot).

That leaves us with a nice, comfortable, and quiet building interior. That’s right! The rock wool does not just provide thermal insulation, but also sound insulation.

Related posts:

Price check, and – surprise!

I needed more rock wool insulation – a whole lot more. It’s for the second floor exterior walls and the attic.

My primary rock wool supplier, the Chicago Green Depot, went out of business about a year ago. I needed to find a new supplier!

Back in the day, the Chicago Green Depot had the best priced rock wool. I got the last batch in early 2012 for around $35.00 per bundle (60 square feet of 3 1/2 inch rock wool batts). All other sources I contacted, including your typical big box home improvements stores, always came in more expensive.

This time around, April 2013, didn’t seem to be any different. The Home Depot had the bundle of rock wool listed for around $43.00! I thought, though, that it couldn’t hurt to double check the pricing for 120 bundles at the Pro-Desk in my local store.

The printout I was handed listed a total of $3,340.80. That breaks down into a unit price of $27.84 per bundle plus tax (or $0.13 per board foot). That is a considerable price drop from the listed $43.00 … around 35%! This is even less that the first batch I bought for the basement installation.

Do I need to say that I was a very happy camper?

Why that 35% price drop? If I go to the Home Depot and place an order over $2,500, I am referred to – what they call – the bid room. Because I am buying in bulk, I have access to a different pricing structure. That said, I would be surprised if that 35% discount will last for long; this may be part of a current promotion.

The significance is that this is the first time that I bought a substantial amount of building materials from a typical big box home improvement store. Materials for a deep energy retrofit like ours were in the past not available, hard to get special orders, and/or too expensive.

Is this a sign that green building materials are on their way into the mainstream?

Related posts:
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Painting, equipment and sidetracking

Thanks to our friends Scott and Carlos, priming the drywall was like eating cake! And – because we got the priming done so quickly – I now can shift gears and start with the proper paint.

While looking for a suitable zero VOC paint product, I ran again into the issue of finding something that has a price point of $30/gallon or less and is not a special order.

After some back and forth, we settled on Behr Premium Plus Interior Eggshell Enamel. It meets our price point and zero VOC requirement, and is labeled low odor.

I found out that low odor does not mean odor free. Don’t get me wrong – it is not obnoxious. In fact, it is really nice to paint without being engulfed in the fumes of other conventional paints that still contain some level of volatile organic compounds (VOC’s). But, as I said, it is not odor free.

While I was in the store, waiting for the color to get mixed, I browsed through the various rollers that were on display. I picked up a rather pricy one to give it a try.

To my surprise, it lasted through the entire paint job, and it still in such good shape that I probably will use it on the second floor. Compare that to the cheap rollers I started with. They lasted for one day and had to go into the trash.

That got me thinking – about the trash we produce because we fall for a lot of cheap stuff. Plus, economically it made sense to get the expensive but good quality roller. By now it has paid for itself, outlasting God knows how many cheap rollers.

It is also a microcosm of what happens with green buildings and deep energy retrofits like ours. A lot of people shy away from the green or more energy efficient option because it appears so expensive when compared the the conventional (cheap) options.

But if green building technologies are executed wisely, they begin to pay for themselves – and may even begin to save some real money at the end.

Wow, I really had a lot to say about painting – didn’t I?

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1st floor priming

Our freshly restored hardwood floors are all carefully covered up, because its time to start painting.

There are two components to this task: the straightforward and the not so straightforward parts.

Getting the paint on the wall is what I would call the straightforward part. Actually, we won’t start with paint. We’ll start by priming all the drywall.

The not so straightforward part has to do with the product choice. We are set on zero VOC primer and paint products. This is non-negotiable, as it has an direct impact on the indoor air quality (IAQ).

Back when we painted the garden unit, I sourced the primer and paint from the Chicago Green Depot, which has gone out of business since. With that, I lost a convenient and affordable source for zero VOC paint products.

“No problem, there must be other products and suppliers.” Yep! But few of them are conveniently accessible (i.e. brick and mortar business), and even fewer have zero VOC products at a reasonable price point.

I mean, if you look around and online, you can find coolest products under the sun out there. But we are not about to spend $60, $50 or even $40 per gallon for paint or primer. Our threshold is at $30/gallon, or preferably less.

That really begins to narrow it down!

For the primer we settled on Bulls Eye Zero Primer-Sealer by Zinsser. Even though it is water based, it has a really thick consistency – almost too thick. We diluted it to the maximum recommended ratio, and it still was thick, but we were able to get a few additional square feet of coverage out of it.

Thank you to our dear friends Scott and Carlos who master roller and brushes like few others do!


Our 2012-2013 heating season…

… has begun – today on October 30th. With outside temperatures over the past weeks barely making it into the 50’s, the the temperature in the garden apartment has now dropped to the point where we need to turn the heat back on.

I didn’t note the day, but I recall turning the heat off around end of April this spring. Our deep energy retrofit with the insulation and air sealing efforts begins to produce some measurable benefits – six months with the thermostat turned off. That’s not bad for Chicago – and good for our pocket book.

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Green Depot Chicago – closed!

The only true green building material supplier in Chicago shut its doors abruptly overnight on May 18th this year.

The store started in 2005 as Chicago Greenmaker Supply. Its founders Ori Sivan and Joe Silver set out to fill the market gap that emerged around green and sustainable building materials. Chicago Greenmaker Supply merged with the Booklyn, N.Y. based Green Depot in 2009.

It looks like the corporate office in Brooklyn pulled the plug overnight. I had a sense that the store had been somewhat struggling, but no idea it was that bad. The Facebook page for the Chicago store had a little note informing about the closure, and now has disappeared altogether.

Some research online indicates that the Chicago store wasn’t the only one that went abruptly out of business. Notes on Yelp show that the San Francisco and Greenport, N.Y. share the same fate.

This really matters, for a number of reasons. I told the story about our dual flush, low flow toilet, which we bought at the Chicago Green Depot. I would have loved to go back to the local store for replacement parts.

They were an excellent resource for VOC free paint at a reasonable price.  The Chicago store supplied all our primer and paint for the garden apartment. We also purchased all our rock wool insulation for the basement and first floor there.

I guess I need to start looking for new sources… And I may not be the only one. The green building material gap in Chicago has opened up again!

What about some of the large home improvement stores that have begun to carry green building materials? They don’t compare in the slightest. First, you have to live in the right neighborhood for those stores to actually carry green products. Then you have to search through all the other clutter to find the green building materials. Can you really trust the “green” designation, or is it just part of the abundant greenwash? Maybe you have a product question and need to find and asked a sales rep … yeah, good luck!

In comparison, at the Chicago Green Depot, you could step inside and had at your fingertips nothing but solid green and sustainable building products, plus good service and valuable expertise.

The question is, who is filling that gap in the Chicago market? If you hear something, please let me know – because I still have a bunch of primer, paint, rock wool and other green building products to buy. I’m sure I’m not the only one!


Clean trim-onomics

While we are talking about salvaged materials and their reuse, let me mention the trim we bought at The Rebuilding Exchange. Although it was very economic, it required some time-consuming prep work.

As one would expect, used trim is typically stained, lacquered or painted. To remove the paint, Cathy took out the Silent Paint Remover and suspended it from a couple of saw horses.


This ‘industrial setup’ allowed her to crank out spanking clean trim at an intimidating speed.

Although the Silent Paint Remover works great on paint (as the name suggests), we found that lacquer and stain is better removed with the Soy Gel product. A couple of coats and a little scrubbing typically do the job.

What we appreciate about the salvaged and cleaned up trim is that it has character. Unlike new material, it has history and tells a story.



I alluded in the last post (Utility sink) that we are ready to paint the freshly installed and finished drywall.

I will not delight you with another time lapse showing us painting, but rather talk about our product choice.

Based on our project principles and goal to provide good indoor air quality (IAQ), using anything but a zero-VOC product was non-negotiable.

I expected, in this day and age, to find a good choice and range of products and suppliers of zero-VOC paints.

Considering that zero-VOC paints are one of the lowest hanging ‘green’ fruits out there, and probably very popular with the ‘green’ and/or ‘green-wash’ minded population, I anticipated that commerce would drive this train fast and furious.

To my surprise, it took me a while to research and find a suitable and affordable product. My experience was vaguely similar to that described in the post Service Desert, although nowhere near as painful.

The Home Depot advertises their ‘eco-option’ products, and has had a strong showing at the USGBC Greenbuild conference over the past few years.

Yet, my local Home Depot does not carry zero-VOC paints. I would have to drive all the way to a store on Chicago’s north side, where they stock zero-VOC paints. And I am apparently not the only one running into this problem.

It appears that rather than leading the market, The Home Depot is following the customer.

Fair enough, let’s try my local Menards. Lo and behold, I find zero-VOC paint for a very good price – and a ‘Green Cert’ label. This is where I got suspicious. There are a couple of ‘green’ designations that I am aware off, such as LEED compliant or Greenguard.

And there are designations that, for whatever reason, feel they have to come up with their own label. This may be an effective marketing strategy, but also confuses the consumer and makes it difficult to separate the green-wash from actual sound sustainable products.

Does the average consumer have the time to research all this? Probably not, and nor have I. Why not turn to someone who has done the research for us, the consumers?

After a moment of thought and short trip, I find myself in the Green Depot, where I have access to a variety of zero-VOC paints in different price ranges.

We opted for the zero-VOC Ivy primer and paint. I didn’t know any better, but our neighbor Norman, who does quite a bit of painting and helped me out, commented about how nice it was without those nasty fumes.


Gas service

I am still intrigued about how the one small boiler will provide domestic hot water and space heating to all three units – once it is hooked up to a gas line.


That is our next task. We do have natural gas service coming to the house. It has been shut off, however, since we bought the house back in April 2009. That made the removal of the convoluted existing gas piping in the building easy and safe.


While we were putting a shopping list together for gas piping and fittings, I remembered that I had a bunch of salvaged material tucked away. I showed it to Pete, one of Mariusz’s crew members, to see if it would be of any use to us.

gas-piping-03 gas-piping-04

His eyes were bugging out. It appeared that we had more than enough salvaged pipe and fittings to get us going. I quickly retired the shopping list and enjoyed the thought of the money I just saved by being thrifty.

Before I got my hands dirty again, I had to contemplate the pipe layout.

Right now, the small boiler is our primary source of energy. With the future solar hot water installation it will be relegated to a backup source. That could mean that our natural gas usage may drop so much that the service fees may rival the actual natural gas costs.

In other words, we would pay more in service fees than for gas, considering that we currently have three meters, which each carry the fees. We quickly decided that it makes economic sense to only keep one meter, i.e. one gas line/meter for the three units.


So much for the mental effort. Time now to flex some muscles.

What made the reuse of the salvaged pipe possible was the pipe thread cutter that Mariusz’s crew brought along. It allowed us to cut the salvaged pipe to the desired length, cut the threads into each end, and connect it with the suitable fittings.

We first connected to the one inch stub coming into the building from the gas meter.

From that one inch line, we ran ¾ inch branches to the boiler and to the kitchens in the basement, 1st and 2nd floor for the gas range connections. Along the way, we strategically placed shut-off valves at the beginning of each ¾ inch branch for safety and maintenance. For the last few feet to the appliance, we used ½ inch pipe with a shut-off valve at the very end.

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This takes care of the gas supply to all three units and it’s time to call the utility company to get the gas turned on!


On the hot chair

We are on the hot chair indeed. Winter is closing in on us and we need the heating equipment installed. To get there we found ourselves exploring some hot and some not so hot options. Here is the story in installments.

Let’s start with the design workshop a little over a year ago. Even though we did not have the mechanical engineering expertise at the table we went home with many ideas on the shape and kind of heating system we need for the building.

We continued our research into the most appropriate systems during the following months and eventually were able to solicit the guidance and expertise of a mechanical engineer.

The starting point

Cathy and I are not fans of forced air systems. They sure are pretty cheap but the dry heat in winter and associated air flow feels very uncomfortable and we both get the creeps thinking about all the indoor air pollutants that get agitated, re-circulated and blown around.

See also:

Impacts of Forced Air Distribution Systems on Homes and Potential for Improvements
Control of asthma triggers in indoor air with air cleaners: a modeling analysis

I grew up with hot water radiators and I am a big fan because of their comfort and effectiveness. It did not take us long to add cast iron baseboard radiators powered by a solar hot water system to our wish list.

We would also like that same solar hot water system to cover the majority of our domestic hot water needs. For the cold and cloudy days, we dream of a biomass furnace as a backup to the solar hot water.

Reality check

We quickly learned that the existing cast iron radiators are too powerful in terms of heat output for our efficient building envelope. I don’t have exact numbers, but based on a back of the envelope calculation one or two of our old radiators per floor would satisfy our heating needs once we are done insulating.


Our green team educated us about the 150 to 180 degree Fahrenheit needed to power cast iron baseboard radiators, on which we had our eyes set.

A solar hot water system operates at about 120 degree Fahrenheit, which would leave us with a delta of 30 to 60 degrees. To bridge that gap we would need a furnace. That would conflict with our zero-energy goal because of the frequency at which we would use the furnace.

Hydronic radiant floor heating would be a perfect match for a solar hot water system and the 100 to 120 degree water it could produce. Our problem is that there are existing beautiful hardwood floors throughout the building, which we would like to restore. Those stand in the way of radiant floor heating.

What about the systems that are installed underneath a floor, attaching to the subfloor between the floor joists? Well, we would have to push the heat through a subfloor, a small air gap and then the hardwood floor. Very old and very dry wood is not a good heat conductor, so we need a better idea.

No matter what we do, we will need a backup heat source to the solar hot water system. My dream of using a biomass furnace as a backup system quickly dissipated as the residential sized efficient models appear only available in Europe.

What about geothermal?

Geothermal would be a costly proposition. Plus, we would rather invest our money in an efficient building envelope, which would allow us to downsize the heating system and our energy consumption.

Similar to the cast iron radiators, the geothermal system would leave us with a temperature delta, in this case of up to 100 degrees Fahrenheit. We would end up paying a big electrical bill for the condensing pumps that would bridge that temperature gap.

Couldn’t we get the power from a photovoltaic array system? Yes, if it is big enough. But we would then be on the path of making everything bigger and more expensive, rather than smaller and more efficient.

Another option would be to dedicate a furnace/boiler to make up the temperature difference. But either option conflicts with our energy efficiency and carbon footprint reduction goals.