Our Finnish Fireplace...that will soon be finished!

For a few months, Todd has been quite busy with the beginnings of our masonry heater.  (If you remember, we have heated our home for two winters with radiant floor heat fueled by propane.)  That is actually our backup system; it has always been our intent to construct a wood-fueled heater in the center of our home.

If you visited Terra Dei at Lutherlyn, you'll remember the masonry heater constructed between the living and bedroom spaces.  Haven's new heater will be based on the same Finnish Fireplace design, described by Albie Barden of Maine Wood Heat in his construction manual from 1984.

(Terra Dei living space circa 1998, featuring our beautiful masonry heater.)

So...why a masonry heater?  Why not a plain old "woodburner"?

If you picture a typical woodburning stove or traditional fireplace/chimney, you build your fire in the firebox.  It burns---giving off some heat to the room---but quite a bit of the energy goes straight up the chimney and is lost.  

In the design history section of his book, Albie describes the Finnish contraflow design that was invented in 1850 by a Swedish engineer by the name of Wimanin.  

At the risk of oversimplifying, here's the gist of the design:  

1.  You build the fire in the firebox and close the doors.  The fire burns in the main chamber.  

2.  Instead of going straight up and out the chimney, the superheated gas travels through a maze-like tunnel built out of firebrick inside the heater. 

3.   The firebrick absorbs the heat and radiates it outward over the next 12-24 hours.

When Todd and I lived at Terra Dei, that translated into two fires a day---one before leaving for work, one upon return---to heat our entire home.  You're talking about an incredibly efficient system, which saves precious resources and translates into huge cost savings for the homeowner.  

I'll share our final cost once we've completed construction.  

(If you have technical questions, leave them in a comment.  I'll have Todd address any details.)

In the meantime, here we go!

(Lutherlyn friends---this heater base is comprised of block salvaged at camp.  I have remnants of Cabin 19 and the old Dining Hall in my basement!)  So far, our cost has been minimal---about $18 for a chimney cleanout door and another $20 for mortar.

Remember where we had the craft table?  (Right above the purple tempera splotch on the floor!)

Once you lift up the concrete board, we had many pieces of plywood and subfloor.

Juli and Micah were both excited about revealing the hole in the floor, so they were anxious to help Daddy with his tools.

And at my request, Todd kid-proofed the hole in the floor to keep kids safe during this point in construction.
(Note, the cat did disappear beneath the floor for a few minutes the other night.  Lucky for all of us, she decided to resurface quickly.)

To be continued!

Pushing the Envelope

(In order to appreciate the events from this past weekend, the reader will want to remember that our straw bale home is currently heated by our backup system, a radiant floor fueled by propane. It's a great incentive to complete our Finnish masonry heater this summer for use in Winter 2010-2011.)

It was inadvertent that we were able to test the passive solar and insulative values of our home last weekend. We really meant to order the propane last week. Really. But it's getting to be good maple weather, which means busy times at home and work.

So we called for propane on Saturday. Sure, they'd be willing to deliver, for an extra $150.00.

Ah. Okay then.

So Saturday began with a feeling of regret that quickly turned into opportunity. As I've mentioned before, the insulation value of the walls of our home is quite high compared to conventional construction. We've created an efficient "envelope" (highly insulated walls, floors, ceilings, windows & doors.) We have a nice amount of passive solar gain through our south-facing windows and a decent amount of thermal mass in the floor. (In layman's terms, thermal mass refers to the ability of a material to absorb heat, to be radiated out over time.) But here's the thing---even though we theoretically knew the insulative value of our home, we had never tested it directly by turning our heat off---until this weekend.

By Saturday morning, we knew we needed to get through two days without using much propane, so we turned the radiant floor system off. (The radiant system works through a thermostat that measures the floor temperature and uses hot water---heated by propane---to keep the floor a constant temperature. The heat from the floor radiates upward and heats everything in its path.) The nice thing is, we can adjust the thermostat to decrease the temperature of the floor, but it also has a switch by which we can simply turn it off.

Looking back, I wish I had treated this weekend more scientifically and taken air and floor temperatures each hour. But anecdotally, here's what happened: we had typical maple weather all weekend, so outdoor temperatures climbed to around 45 degrees F during the day and dipped below freezing at night for both Saturday and Sunday. Each day, the passive solar energy raised Haven's interior temperature to around 69 degrees. Overnight, the air temperature in our home came down to around 64 degrees.

Overall, we were extremely pleased with how we fared at Haven this weekend. There were a lot of variables at play, such as the fairly pleasant March weather with sunshine. (Certainly, if we hadn't had sun, the house wouldn't have been as warm each day.)

So what are the potential implications of our inadvertent experiment? My conclusion is that since I am home during the day, I'll be able to monitor the outside weather and adjust the thermostat on our radiant system accordingly to greatly reduce our demand for propane on sunny days. It makes me think back to a Cape Cod we used to own, to times when we considered ourselves lucky to be able to turn the furnace off toward the end of April. What a great opportunity to be able to reduce our fuel use a month and a half earlier! It also brought me back to our time at Terra Dei, learning to build smaller fires each day as Spring progressed, so as not to waste wood and overheat the house.  It reminded me that life it built on a learning curve.

The owner of the propane company personally made our delivery yesterday. Having helped Fred choose the size and site of the tank for our proposed radiant heating system, he was curious as to how we made out this winter. I described how pleasant the floor was to walk on, then related our "experiment" from turning the system off this past weekend. He smiled ruefully, saying, "Well that's great for you, but not good news for me!" Though I kept quiet, I was dying to say, "Just wait until our masonry heater is in place next year!"

Instead, I chose to smile and wish him a good day.

Thanks for joining me along our journey!
Grace
xxoo

On the Horizon: Straw Bale Workshops

While proofreading the newsletter for the environmental education center at Lutherlyn, I was thrilled to note that plans have been set in stone for three straw bale workshops this spring. Lutherlyn is in the process of building its second straw bale structure, a worship and music center. (Terra Dei was Lutherlyn's first straw bale building, to which we credit our early straw bale experience and where we lived for four years.)

March 21-27, 2010: Join us for an Alternative Spring Break focusing on straw bale construction. This week-long program will introduce students and campus groups to the basics of straw bale construction and earth plastering.

May 14-16, 2010: We will be offering a combination Straw Bale Construction and Earth Plastering Workshop. This event will cover the basics of design, construction, and finishing of straw bale walls. It will include plenty of hands-on experience.

May 22-23, 2010: Come for our Straw Bale Work Days! These days will be spent stacking and plastering bales. All volunteers are welcome to attend.

(On a side note, yours truly will be helping teach these events. I can't wait to get my hands on that earth plaster!)

For more information and to register for these events, please contact the LEEP office:

Lutherlyn Environmental Education Program
724-865-9079
leep@lutherlyn.com

Seriously, Why Straw Bale?

When I began working on my radiant floor post the other day, I realized that there are so many other posts I need to write for the sustainable part of this blog---top of the list being reasons why a person would try to build a house out of straw. Living in our particular part of the northeastern United States, straw bale construction isn't something you see often. The only exposure most people in this region have to green building is what they may have caught on HGTV. That makes teaching with homes like Terra Dei and Haven Homestead a special joy. To take a visitor from the mindset of "Why on earth would you want to build with straw?" to "Boy, that's pretty cool," is a gift we're blessed to give. Our aim is to share open-mindedness, possibility and vision, not to convince visitors that they could or should build a straw bale house.

Here's the thing, the answer to "Why build with bales?" has already been published many times by experts in the field. Not being one to reinvent the wheel, what I'd like to do is give you a rundown of a list compiled by Paul Lacinski and Michel Bergeron, from their book, Serious Straw Bale. In their first chapter they list eight excellent reasons why building with bales is a viable alternative to conventional construction, as listed here.

1. Beauty
I love that this is the first benefit they give for building with straw, because beauty itself attracts me most to straw bale construction. The combination of straw walls and earth plaster could perhaps be considered the antithesis of conventional home construction---both in types of material and in aesthetics. There is a subtle beauty to a bale wall, seen in the gentle curves and in the way the light falls on the plaster throughout the day.


The above photo is from one of my favorite spots in Haven. Note the rounded windowsills, the deep ledge where one can curl up with a blanket and a book. Above the chair, a truth window bears witness to the origin of the wall.

2. Insulation Value
According to Lacinski and Bergeron, "Plastered bales provide a highly insulative wall at a price that is competitive with quality conventional construction" (p. 5). In layman's terms, bale walls can provide more insulation than conventional walls for around the same cost.

3. Nontoxic
In a world that we have increasingly filled with pollutants, this is a fundamental reason to choose straw bale construction. Straw is a natural material. "Unlike many manufactured building products, they [straw walls] contain no toxic ingredients and are chemically stable. They will release no unhealthy chemicals into your home, and will not emit poisonous fumes in case of a fire" (p. 9). At Haven, we did our best to choose nontoxic building/furnishing materials within our budget at every step. Straw and plastered walls were an early part of this continual process.

4. Use of Resources
When you choose to build a home, you are choosing to use resources. Your choice is to reuse material from previous construction or to use new material. We did some of each. Straw is a new material, but it is one that is readily available in our area. It can be grown in one season. In some locations straw is actually burned in the field as a waste product of agriculture. By using straw, "we might also reduce the pressure on forests (the most important carbon sinks and oxygen producers on the planet) and the demand for relatively energy- and pollution-intensive industrial insulation materials" (p. 10).

5. Economical
In these tight economic times, cost is a factor in everything we do. (Had we known what the last four years would bring financially, I don't know that we would have chosen to build when we did, if at all.) Our family was rapidly outgrowing our two bedroom Cape Cod house at the time. We were faced with buying a larger existing home, building a conventional home or building a straw bale home. We chose to build a straw bale home because we have experience in this area. We knew that if we did most of the construction ourselves we would save money in the process. Building our own straw bale home would allow us to obtain "much more home for our money", as the popular saying goes. According to Lacinski and Bergeron, "Bale construction is getting to be cost-competitive with good-quality stick-framed construction, assuming a tight design that doesn't drive labor costs through the roof" (p. 10).

6. Owner-Builder Friendly
Aptly written, these authors describe straw bale as "well suited to a 'gang of friends' method of construction" (p. 12). Especially for raising the walls, many hands make light work. We were able to place the bales for the first floor using two work weekends. Along the entire journey we have been fortunate to have good friends and family members who took our venture as their own and have been intricately involved in the construction and finishing details of our home. Working with friends saves time and money. More than that, it allows you to build more satisfying relationships with people you thought you knew well prior to building.

7. Fun
Different people have varying ideas as to what constitutes "fun". I wouldn't say that I particularly enjoy many of the jobs in construction, until you get to mudding and plastering the walls. For me, those jobs contain a great deal of creative fun! That is one of the fabulous parts of building your own home: people are free to try out a vast number of different jobs and see what they enjoy the most. There's also something to be said for the "synergy of group effort" (p. 12), stepping back and saying, "Can you believe we accomplished all this together?"


The above photo is an example of my idea of fun. This is the inside of my front door, which leads into a mudroom. Note the rounded walls next to the door, the curve of the interior corner! We were near the end of the interior plastering, and the bare wall was begging for some variation. My inspiration for cutting a niche into the bale wall was taken from Athena and Bill Steen's book, The Beauty of Straw Bale Homes. Todd used a chainsaw to carve into the bale. I used earth plaster to shape a triangular shelf, and the Trinity niche was born. The small mudroom was also the perfect place to apply a darker color of plaster---just for fun.

8. Durable
Bale buildings have been created for almost as long as the baling machine has been in existence. Much of the durability of bale walls comes from proper finishing with some type of plaster. When detailed correctly they are actually fire resistant; "plastered bale-wall systems have outperformed wood-framed walls in fire tests" (p. 13). Rodents and insects have a hard time finding a home in a wall that has been plastered and sealed off. Though we don't worry about it in our area, bale walls have even been tested and considered a viable option for earthquake-prone areas (p. 15).

Many thanks to Paul Lacinski and Michel Bergeron for sharing their collective experience with us in Serious Straw Bale. It is well known in straw bale circles and a book we trusted throughout the building process.

I will say this: the experiences I have had building two different straw bale structures has changed my life for the better. Not only have we created beautiful, safe, warm homes, I have personally learned many different construction skills along the way. An exerpt from the Christmas letter I typed last night: "Words cannot express how we’ve grown closer as a family simply because we endured the building process. The house becomes an excellent metaphor for building our life together, of taking separate agendas and meshing them into one structure that can hold us all."

That's not to say that everything along the building journey has been easy. On another day, I'll be sure to compile a post of "Boy, I wish we had known xyz about building," or "Yeah, that wasn't our best idea." But for today, from the office where I sit, I have a pretty optimistic view of our Life Under a Blue Roof. Thanks for sharing our journey!

Have you ever visited or built a structure of straw bales? Post a comment and let us know!