Can This 100-Year-Old Home Be Carbon Free?
Sketch of our 1916 home - courtesy of Fred Foster.
In 1885, Edward Hall along with his brother sold their business in Rochester, New York for $30,000. They moved to our neighborhood in Saint Paul and with a few other partners established the area’s first manufacturing company, the Saint Anthony Park Furniture Company, named after the neighborhood.
Before we purchased our home in 2016, one of the sellers pointed to a framed building permit on the wall, which indicated that Edward Hall was the original owner of the home which he built in 1916. She offered us a two-seater couch from his furniture company. She also handed me a cardboard box filled with her research.
I learned that by 1916, Hall's interests had shifted from furniture to real estate. Our house was one he built probably on speculation with a local architect, D.C. Bennett.
The initial plan for the Saint Anthony Park neighborhood itself was drafted in 1872 by the towering Twin Cities historical figure Horace Cleveland. However, it failed. Cleveland, who went on to design most of the major parks and parkways in the Twin Cities over the next few decades, originally designed the neighborhood to accommodate large estate homes. This idea proved unappealing to buyers and so after the turn of the twentieth century, the area’s developers switched tactics and began to market homes to the middle class on smaller lots.
Our house was one of those. According to our original building permit, the house cost $5,000 to make. In an ad/article the seller had found in the July 13, 1919 edition of the Minneapolis Morning Tribune, the architect, D.C. Bennett, describes it as “Dutch Colonial Style Bungalow [That] Allows Good Taste at Low Cost.”
I am happy to report that the house has stood the test of time and still has many luxurious features, like hardwood floors, that could never be replicated.
However, like most old homes in the United States, what it doesn’t have is energy efficiency.
Home performance professionals will often point to the attic, basement, and walls as the order in which energy efficiency projects should be tackled in old homes.
For example, when we arrived, the attic still contained sheets of brown horsehair insulation nailed to the rafters. Horsehair allowed air to move through it while providing some insulation value. What it was doing in the rafters of the house, however, beats me. We had it removed along with the rest of the fiberglass bats that lined the attic floor. We replaced the knob-and-tube wiring that was up there as well and blew in cellulose to R-55.
Like the old saying goes, don’t look a gift horse in the mouth—unless it’s hanging from your ceiling!
That still left us with the basement and walls.
In the basement, asbestos wrapped around some pipes. Knob-and-tube wiring also lurked in the ceiling. We had the asbestos and all the plaster and lath ceiling plus plaster inside walls professionally removed.
Since the ceiling and walls were removed, the rim joists that sit atop the cinder block perimeter of the house are the last line of defense to the elements outside besides the brick veneer. With those rim joists exposed, air is streaming in like never before, and weird things were happening with the thermostats, especially when it reached -4 degrees the other night.
Rim joists have always meant significant air leakage in old homes, but builders and architects at the time considered air infiltration acceptable as the thought was/is that a building must breathe to prevent moisture from building up.
However, leaky joists contribute to what building scientists call the "stack effect" which is where cool air gets sucked from the bottom of the house and then it warm air gets pushed out the top of the house. The more the rim joists remain unsealed or uncovered from the outside, air penetration and heat/cooling losses are multiplied.
The rim joists are a weak spot in most old homes, not just ours. Soon, we will have them sealed with spray foam.
For the walls, we will insulate them in the basement after many discussions with Green Home Club’s Green Home AI chatbot and checks with professionals about a wall assembly that will allow for some ventilation.
Upstairs, the walls were last insulated with blow in mineral wool - in 1933. They took advantage of the recently invented blow-in machines. I know this only because of two building permits issued by the Saint Paul electrical department for the work, which I found at the historical society.
However, we can’t add new insulation yet to the walls upstairs until the knob-and-tube wiring is removed.
As you can see, things must happen in a certain order but what that order is, is sometimes a matter for debate. Do we insulate the rim joists before calling the electrician? The answer is that it depends.
What is certain is that we have an oversized boiler—four times bigger than it needs to be once all the air sealing and insulation is done to the house. The old natural gas boiler we have now replaced the oil-fired one which replaced the original coal fired steam heat unit. It is interesting to see remnants of each system in the basement. For example, there was a distinct oil smell from the spot where the oil tank used to sit in the basement when we pulled up the concrete floor and the pipes leading to the radiators are large enough for steam.
The Prize: An Air-to-water Heat Pump
I would say our biggest priority is replacing the natural gas boiler with a heat pump that works with radiators. This alone will reduce our carbon footprint by 50%. Air-to-water heat pumps as they are called here are very popular in England and Japan and other countries. The only catch is that the water distributed throughout the house will be at a lower temperature therefore the house should be well sealed to keep that precious heat in. It also needs to have a backup source of heat if the pump stops working at negative degrees.
This leads to a growing list of other decisions like what kind of backup heat (we are thinking of an extra tank for thermal storage and backup electric heat if needed). There are also design considerations as to in floor heat vs under floor heat vs new low temperature radiators.
The pipes, as mentioned, that service the old cast iron radiators were designed for steam and could benefit from updating.
Our plan today (as opposed to our plan tomorrow) is to keep some of the old radiators, change those pipes and add in floor heat for the basement and under floor heat for the first 1st floor. Using the same system, there’s a cool way to have heating and cooling run up through the attic with a small duct high velocity air handle in the attic. This is still in the contractor proposal stage, each contractor has a different opinion and that looks like the most expensive part.
Thankfully, at this time I am happy to report that we have hired a building professional (general contractor) who shares my passion for eco renovation and is going to help with the scheduling and management of our project from here on out.
His name is Joseph Tim of Minneapolis, and his outfit is called Better Builds. Working with a general contractor requires a great deal of trust and Tim seems to share my passion for and has a lot more knowledge of eco-building practices that will work for our home.
Removing the basement ceiling has revealed 100 years of wiring and plumbing that needs to be replaced - there’s still so much to do!
Still, I do sometimes wonder if we made a mistake. We all miss the basement – the laundry, bathroom and sauna; it was a mess and looked unlivable, but at least it worked.
In the end, I am sure we will realize that we are in the middle of a historic opportunity (rather than a problem), and we are right to take advantage.
The project has its shining moments as well. The Christmas miracle was when a HVAC contractor came over within 30 minutes of getting my call to look at our thermostats. He lowered the water temperatures in the boiler. For now, everybody is happy with the temperature, after complaining that it was way “too hot” upstairs. The cost? Free!
We still have a lot of steps to carry out to achieve a decarbonized home.
Before undertaking the project, I called my cousin Fletcher a builder in Connecticut. I asked him if he thought it was a good idea.
“Of course,” he said, “it will give you something to do!”
That’s turned out to be an understatement.
