Read reviews of the first three books in the Sustainable Essential Building Series by New Society Publishers – Hempcrete Construction, Building Science and Prefab Straw Bale Construction.
We get a code update from Martin Hammer, the main and contributing author of the two most recently adopted U.S. strawbale building codes
This article first appeared in The Owner Builder 196 August/September 2016. www.theownerbuilder.com.au
By Brian Hodge
As we embark on our 20th owner-built home, I reflect back over the progress since purchasing property last year.
We were surprised the property didn’t have power, sewer, or water but discovered it actually had sewer connection just over the back fence. We were somewhat pleased when we received the quote for electricity connection of $5,050. Mind you, that did not include the connection of the power to our meter box.
Having mentioned the meter box, I am flooded with the memory of its incorrect positioning in my unavoidable absence and the challenges that we were faced with as a consequence (see TOB 195 June/July 2016). But who can complain. The end result was that we have revisited the design and now have a better one that is more interesting. And who can forget the bonus sewer connection at the back of the block, which will save us around $10,000 that we would have spent for a septic system.
A place to run courses
When we first went looking for land our primary motivation was to get a low cost piece of land on which we could run the practical part of our owner-builder straw bale building workshops. This was a precursor to being willing to sell the straw bale house in Ladys Pass. To be a straw bale building consultant with nowhere to do courses and nothing to show people was not an option and the solution had to make financial sense.
Consequently, I did an internet search for ‘land under $50,000 Victoria.’ The result was land in Loch Sport, which was too small and, from previous experience, has too many mosquitoes, and land in Inglewood, Victoria. Inglewood is in central Victoria about 35 minutes north of Bendigo with a population of a bit over 1,000. It was established in 1859 and is still a great place to find gold. It has a good supermarket, hospital, permanent doctor, pharmacy and most important, a couple of good old fashioned pubs for great meals. It is also the town where my youngest son, his wife and two of my grandchildren are located. However, the criteria were primarily price and size.
There was an 8000m2 block for around $45,000 near a light industrial area, a 2000m2 for $70,000 or a 1000m2 for $35,000. We put in an offer of $33,000 on the last block, which was accepted.
The only issue, which was a big one, was its orientation. It is only 20 metres wide and faces north-west. In order to control heat input and get some passive solar benefit in the design, we had to design a house that is twisted on the property. This option consumes a lot of land, which was complicated by our need for wide eaves for a straw bale house. Regulations stipulate that living area windows must have a minimum of 1000mm of clear sky from the boundary, which meant that we had to be set in from the side boundary a minimum of 1900mm to allow for the 900mm eaves. We also needed truck access to the backyard to take deliveries of bales etc. for workshops, further restricting our build space.
We finally settled on the concept of building a U shaped house with a central courtyard as this would enable us to get passive solar benefit in the master bedroom and living area. Not a huge amount, but enough to make a difference. It also provided us with a outdoor private area, which is important to us as we have lived on country properties for the past 12 years.
I had our energy assessors check to see what difference this adjusted orientation would make on stage one of the construction, as opposed to building parallel to the front boundary. We were surprised that the energy rating actually went up from 5.4 stars to 6.3 stars even though there is only one window that faces north.
As we are building in central Victoria, the energy rating is primarily directed toward the energy required for winter heating. However, we get some really nasty weather in summer with temperatures reaching high 30s and even mid 40s. Consequently the design criteria also included resistance to summer heat. The central courtyard faces due west, however it has a deep verandah to protect smallish windows from the afternoon heat from the west, and the windows facing east are limited.
One of the big concerns for restricting heat input in summer is to avoid doors that open directly into the house from the north, as it is the north wind that brings high temperatures to the area. I have therefore included a good size entry on the northern end of the house with the external door facing east, which will dramatically reduce the impact of those hot northerly winds.
The cooler summer breezes often come from the south-east, so we have included casement windows on the south-eastern boundary to funnel those cool breezes through the house. The benefit of correctly hinged casement windows is that they tend to trap the breeze and funnel it into the house rather than simply working with straight airflow. When you are trying to get cool air into your home it is best to open the windward windows fully but close the windows on the opposite side of the house to 50%, as this creates a vacuum resulting in greater airflow.
As this is a residential block I expect that airflow will be a bit of a challenge as we have boundary fences which will restrict it. I have also incorporated a flat ceiling in part of the house in order to accommodate ducting for an air circulation pump to force the early morning cool air through the house if the temperature in the house is higher than the temperature outside. Our previous straw bale house in Ladys Pass had the same issue, which was overcome using an evaporative cooler as an air circulation pump. The cooling function of the unit was hardly ever used, and would not have been missed, so I am planning on simply fitting an air pump this time.
The master bedroom window faces north onto the central courtyard, however the window is not within the shadow of the verandah roof so we will get good passive solar benefit in winter. It also means that we have a private outlook, and with Molly, our big guard dog, we are assured of security! (Molly is a miniature Maltese Shiatsu)
As this is house number 20 for us personally, it was difficult to find something a bit different to do, so we eventually settled on a curved roof with a curved ceiling. This will be achieved by building box trusses on site. It is a very cost effective method of roof construction and I am looking forward to trying it out, as I have never done it before.
With all the design, engineering and building permit issues behind us it is now time to get to work and build it. I am going to take my time and enjoy the process as I suspect this will be the last home that I build, although many people scoff at this idea, thinking that I am either crazy for building so many or that I am addicted to the process. Personally I am not sure, but I am going to enjoy this project as if it is my last.
Brian Hodge is the director of Anvill Straw Bale Building Consultants. He has nearly 40 years experience in the building trade, and now consults predominantly on straw bale construction. Brian is the author of ‘Building your straw bale home’ and will be blogging about his build. Anvill Straw Bale Building Consultants: Whether you are building a mansion or to a strict budget, we are here to help. www.straw-bale-houses.com
For too long the insurance industry has held the owners of straw bale buildings captive while they sway back and forth with the prevailing winds when it comes to insuring our buildings. We begin to address this issue in the first of a series of articles on this topic.
By Andrew Morrison of strawbale.com
There are many different approaches to framing a straw bale house; however, there is one in particular that I have used on the vast majority of my projects over the years. It is a post and beam frame system with roots in conventional framing techniques. Because I came to straw bale construction many years ago as a general contractor practicing conventional construction, I brought some of that detailing over. I should preface this article by saying that there are right ways of framing and wrong ways of framing. The system I describe in this article lands in the “right way” column, but so do many other styles. As long as you are working with a structurally sound and safe system that brings you the best results possible for your style of building, then go for it.
One of the first details that often surprises people is the spacing of the posts in the system I use. I hear people talk about wanting to reduce the amount of notching in the bales by spreading their posts out as far as possible. I disagree with this approach and instead keep my posts relatively close together: no more than 6’ apart. One reason for this is that when the bales are stacked in between posts that are set far apart, there is no point of attachment for the bales other than the top and bottom of the wall. As such, the wall becomes weak as it is stacked higher. When posts are set closer together, the notches at each location provide a point of connection to the frame and make the wall much stronger both during construction and for the life of the structure.
One way I keep the posts close together is by incorporating them into the window and door frames. By using 4×4 posts as the king studs I end up with wider nailing surfaces on either side of the opening. This allows me to attach the finish trim, plaster channel and/or plaster lath, and welded wire mesh around every opening with positive attachment to the frame. These king studs serve two purposes by providing the nailing surface and by acting as part of the overall structural frame. Because windows and doors are placed in many locations around the home, and because I otherwise limit my post spacing to no more than 6’, I can minimize the wall beam size as a result. This minimal wall beam is important because the bigger the beam, the more expensive it will be. Further, larger beams are made from larger trees (unless an engineered beam is used) and I want to reduce the size of the trees I am using in my projects for environmental reasons.
Okay, let’s take a look at how the system works and why it can save time and money in your building process. I’ll simply lay out the process so you can see, step-by-step, how it comes together.
By Huff ‘n’ Puff Constructions
Editors Note: We plan to have a comprehensive article covering as many of the tilt-up straw panel systems on the global market as we can in Issue #64 due out in July. Please also note that the images associated with the thumbnails on this page are of large size. We wanted to keep them original size to allow you to see details clearly.
Recent times have brought an increasing wave of environmental and energy efficiency awareness in the building industry throughout Australia. This increased awareness of the effect of logging on our forests, lakes, and streams, as well as heightened concern for the energy cost and efficiency of our buildings and ever-increasing costs of construction materials is bringing tremendous pressure for change to the Australian building industry.
A primary focus of this change is the development of alternative forms of construction for single and multi-family housing as well as commercial and industrial buildings. With a tradition that dates back almost 200 years, the Australian building industry has utilized timber extensively for use in wood frame construction, concentration on wood framing timber as the principal raw material for the structural shell of the majority of our housing and much of our light commercial structures has tremendously diminished our hard wood and softwood forest resources in Australia.
The cost of framing timber has more than doubled in the past five years. The price of timber is projected to continue to rise over the course of the next decade with additional concerns over the quality and availability of that timber. The price and in some areas the availability of energy has added a new and important factor in most building projects. With these facts in mind, the building industry, known for its rigidity and resistance to change, will have to look at replacement materials for framing timber in home and commercial construction.
We are in the process of developing and bringing to the market place a unique, and ecologically sound, structural insulated panel building system. These panels will be able to be put into place by two people. This structural panel system provides a cost-effective, building system that is based on an environmentally responsible manufacturing process.
Huff ‘n’ Puff Constructions are manufacturing a structural super insulated panel that uses as its core material waste agricultural cereal straw from wheat and other cereals commonly grown in Australia.
With the recent high rise in energy costs and energy availability this product’s value to the builder and his client is a product that is more important now than ever before. THE SITUPS* is highly competitive to conventional building methods. With the reduced construction time, energy savings, non-toxic nature of the product, and strength and durability of the product indicate we have a building system whose time has come.
It was on the banks of the Murrumbidgee River at Hay that we made our first SITUP. This event was first published in The Last Straw many moons ago now. It involved a BIG chain saw and a jumbo straw bale 2.4 m x 1.2 m x 1.2 m (8’x4’x4’). We made three panels out of the one bale and had a lot of waste with the “method” we used at that time. Back to the drawing board… [Huff ‘n’ Puff shared this technique in TLS #24, Winter of 1998]
In between building straw bale houses and wineries we kept on refining the process over the past 8 years. Eventually we got an order to make 60 x 2.4 x 1.2 x 150 mm panels for a straw bale house that we were building in Kangaroo Valley, near Sydney. These panels were to be used for the internal walls and are non-load bearing.
We had these internal panels tested at the University of Western Sydney. Our tests were to establish their load bearing and wind loading capacity. They did not pass muster for load bearing but showed us their potential. However the size of 150 mm wide proved to be very hard to manufacture and will need a lot of refining in the process to make them a worthwhile proposition.
FIRST LOAD BEARING PROTOYPES
After many experiments and research we have chosen a method that we feel has the potential to change the way we build with straw bales now and into the future. We also realise that several straw panel systems are now on the market in parts of Europe and Canada. Our opinion is that more is good and will only lead to the acceptance of building a house, flats and even high rise units and many other types of building by adopting straw as the medium in tilt-up wall technology.
We have now completed two SITUP buildings in New South Wales. One close to home in a suburb of Wagga Wagga, and the other on a farm near Yass, which is close to Canberra. We are now filling an order for a three-pavilion SITUPS home in the Hunter Valley of New South Wales.
The SITUPS are currently 2.450 to 3.000 metres high and come in various widths from 600 mm to 1.2 metres. We can also make them between 350 mm and 450 mm wide. The cladding can be a variety of material from renders to weatherboard, corrugated iron and many other forms of external sheeting. Internally they can also be clad in render or Gyprock and various types of lining boards.
We are also developing a portable SITUPS factory to make these on a building site.
The SITUPS will greatly reduce carbon emissions from new buildings through savings during manufacture and the operation of the building. We already know this, having built many straw bale buildings since 1998 and together with 145 straw bale building workshops now completed.
Our goal is twofold; first, to reduce the carbon impact of modern buildings with the SITUPS and; second, to be able to utilize a waste product of our wheat and rice cereal growing in Australia where rice straw alone is burnt at an alarming rate. Some one million tonnes goes up in smoke (particulates and carbon) every year. Enough straw to build, say, 44,000 three-bedroom SITUPS homes on an annual basis and that is only from the rice grown in one area of Australia.
All the other benefits that come with straw bale homes that we have know of and practiced over the past 17 years apply equally to the SITUPS. The main difference to conventional building with straw bales is that the SITUPS are uniform pre-compressed at time of manufacture and hence are very fast to build with, saving time and money.
* The SITUPS is a registered trademark of Huff ‘n’ Puff Constructions
John Glassford and Susan Wingate-Pearse, The Straw Wolf and My Little Wolverine
Huff ‘n’ Puff Constructions
22-24 Moore Street
GANMAIN N.S.W. 2702.
61 2 6927 6027 Work
0412 11 61 57 Mobile
By Frank Tettemer, ONBC Director
This definitely was the most fun to be had all winter.
Timing is everything, and this year’s gathering of the clan at Camp Kawartha, near Lakefield Ontario, warmed my heart during one of the coldest of Canadian winters. With temperatures outside the straw bale conference room dipping to -24C (-11F) at night, the crackling fire in the wood stove provided a popular place to gather around over the weekend.
Tina Therrien’s welcome and opening remarks on Saturday morning lit the flame of curiosity and instilled the warm comradeship that nicely permeated the weekend conference. Her dedication to forming the Ontario Straw Bale Building Coalition 15 years ago, and her continuance as Chairperson has been instrumental in supporting this organization’s transformation into what it is today; the Ontario Natural Building Coalition. www.naturalbuildingcoalition.ca
Jacob Deva Racusin spoke of many things around building impact, social justice, and creativity. Lessons learned were all about making straw bale walls using additional layers and materials. The synergy of plaster, straw, cellulose, rain screens, and cladding can easily place natural materials into the Passivehaus world of warmth.
Chris Magwood’s presentation reached out to owner-builders, professionals, and designers, about the importance of setting goals and priorities, well before the excavator arrives on site. Emphasizing that everyone’s needs are different, and establishing priorities for each individual is the first step in good design. And when it’s time to compare different materials and building components, his new book, “Making Better Buildings”, covers everything vital and appropriate.
David Eisenberg’s warm voice and brilliant experiences always open my heart. While transplanting Kathleen O’Brien’s Emerge Leadership project to the forests and lakes of Ontario, he found fertile soil, within this group of 80 aware and alert natural builders. Though it must have been a challenge for him, to travel the distance with a temperature difference of +80F to -11F, ‘Desert Dave’ seemed undaunted, as he patiently germinated the seeds for emerging leaders, to carry on the work of building not just net-zero housing, but to develop ways in which every new building is restorative and adds benefits to the natural environment.
Dawn Marie Smith traveled from Victoria, BC to show us how to use alternative methods to achieve code acceptance and obtain that elusive building permit. Reaching for the carrot of sustainable building is not always easy, and the ASRi and their publication, the Alternative Solutions Resource Initiatives’ Straw Bale Alternative Solutions Resource (ASR) manual, has made the work of digging these carrots much more straight forward. I loved how her experiences with Emerge Leadership helped to add sprinkles of additional insights during David Eisenbergs’ presentation.
Relaxing after dinner on Saturday, we were treated to our own 5×5 slideshow – five photos from a couple dozen contributors – who each had five minutes to talk about their photos. Hilarious and inspiring, the show was a fun warm-up to the evening, that included libations from a selection of organic wines and craft brewed beers from the Bale Heart Bar, that livened up our senses for socializing, while singer-songwriter Rick Fines strummed and sang, caressing the spirit of inspiration in us all.
Did I mention how well we were treated and fed by the Camp Kawartha cooks? They really knew how to accommodate the evolved diets of our participants, with delicious meals and healthy snacks.
Thanks to all, for your spirited participation, in making this year one of the finest conferences ever.
Dawn Marie Smith – http://www.asri.ca/
Rick Fines – http://rickfines.ca/
Issue #62 is the first full-color issue of The Last Straw. It is also full of the kind of content you have come to expect. Issue #63 is due out in April, which means we will be publishing issues at the end of each quarter. If you have a project or details of your work that you want to share, make sure to send us you articles soon! In order to keep up with our schedule we need to receive a steady flow of stories from the field.
In this Issue:
- Natural Building in Korea
- Choosing Natural Hydraulic Lime Plasters
- Straw Bales and Building Science
- Permitting your bale building
- Fueillette House
- IRC Approval
- German Fire Test
We hope you consider a subscription in order to receive each issue uninterrupted and at a discount.
By Andrew Morrison
There has been so much talk over the years around the “straw bale building table” about building codes and how they get in the way of our ability to build with natural materials. I have heard people talk about how building officials have ruined their dreams time and again, and stories about building officials requiring so many “over the top” details in a home that building it became impossible. You can imagine, therefore, that I tend to shock people when I tell them that I actually like building officials and that I prefer job sites that have an inspection process over those where no building officials visit the site. Let me explain.
If you have ever been to a job site where no building inspections take place and no plan review is required, you may have seen what I have seen: a house that is built below code with several omissions and/or mistakes which put the occupants at risk. For example, deciding to save a little money by not installing collar-ties between your rafters could lead to the roof’s collapse and your death or injury. That’s certainly not worth the money saved. Just because you are not required to build to code doesn’t mean you shouldn’t. A lot of thought has gone in to developing the building codes we use both here in the States and abroad. You may find that some are overkill and some are unnecessary based on the scope of your project; however, I strongly recommend that you adopt as many of the code provisions as you can in order to provide a safe home for you and your family.
As an update to this post about the Feuillette House in France, here is a patent in the United States for straw bale construction. It was filed on June 6, 1921 and is a very interesting read for the bale construction history buffs out there. The author was Emile Feuillette himself and approved on June 6, 1921.
This is not the oldest patent on bale construction as we documented back in Issue #21 in the Winter of 1998. That title goes to Josiah M. Leeds (of Indiana, not Nebraska) in 1880. The article describes and contains illustrations of three subsequent straw bale building patents (1885, 1903, and 1905). Issue 21 can be ordered on our CD of the first 40 Issues here.