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Saturday, March 22, 2008

Home Design in Cold Climates

Home Design in Cold Climates
by Douglas Barnes


I am currently in the process of designing a home for myself and my wife. Living in Canada, the number one priority is warmth. To solve that problem, we must focus on energy capture and energy storage.

To capture energy, the house will be oriented with the long side facing the sun. This side will be fenestrated to allow the entry of solar energy from the sun (which, strikes the Earth with over 950 Watts per hour per square metre before any loses come into play). The energy needs to be stored once it has entered the home or the house will heat up nicely in the daytime but become quite cold in the evening. In this case, the main storage will be a monolithic concrete slab floor.[1] In addition to this storage, there will be a masonry fireplace, whose massive brick structure will hold energy, and earthen or lime rendering of the walls will also help.

Windows are good. Too many windows are bad. So, fenestration will be reasonable. We will match percentage of window area with our latitude. We’ll be building in Southern Ontario at about 45o north latitude, so we’ll have around 45% window area on the southern wall.[2] Too many passive solar homes in Ontario have nervously designed what amount to glass walls on the south side thinking that if a little is good, a lot is better. The result is over-heated homes. While there are some who might not mind 30oC temperatures inside in January, they certainly don’t like the over-heating that will occur at other times of the year.

The Canadian Housing and Mortgage Corporation recommends making thermal mass (the dense material that serves as heat storage – concrete, brick, and mud in this case) be around ten times greater in area than the area of sun-side fenestration.

General layout of the rooms recognizes at what times the rooms are used during the day. The first place people go in the morning is the kitchen. It therefore makes sense to place the kitchen on the southeast side of the building (northeast if you are in the southern hemisphere). In this way, light and solar heat is available first thing in the morning. From there, other rooms follow the sun according to the usage of the room. The exception is the dining room which is placed next to the kitchen for practical reasons.

With this information, it is possible to design a building that performs brilliantly from an energy perspective. However, there is no guarantee that the house will be even remotely livable inside.[3] To make the home a place that I actually want to live in and keep for the rest of my life, I am using Christopher Alexander’s A Pattern Language to design the home.

Another advantage to the passive solar layout is that it creates a nice pattern in the home. A long, thin home has a series of rooms one after another. This helps create privacy in the home and avoids giving the house an overcrowded feeling.

In too many modern homes these days, visitors immediately have full view of the private areas of the home as soon as they enter, and sometimes as they approach the main entrance. There needs to be a gradient of intimacy from public to private areas of the house.


The interior space must have a natural flow that takes into account the uses of the space inside. Hallways and corridors have been avoided as much as possible. Rather, movement flows through rooms making some areas very social and inviting to people moving through the building.


The common area of the home is at the heart of the building that intersects with all the major traffic flows throughout the home.

There is a sequence of seating spaces in the home that offer different levels of intimacy. The living room has a main seating area that is very social. It’s on the main path through the home, in a sunny place, and centrally located. Just off this main space are two other seating options ranging from semi-private to private. There is also a sunny nook off the kitchen. An additional seating space will be available on the second floor (which is currently being revised).

While this does not include every pattern I used in the design, it highlights the main ones that had the most influence in guiding the layout of the interior spaces.

1. The optimal thickness for thermal mass storage is 4 inches thick. Any thicker and diminishing returns start. If it is too thin, it will heat up and cool down too readily rendering the mass less effective. (For example, tile on subflooring heats up and cools down so fast as to have no appreciable effect in storing energy.)

2. This is Bill Mollison’s rule of thumb, and I have checked it out with a local architect and friend, Steve Hilditch (hilditch-architect.com), who has designed passive solar homes. Steve agrees that Mollison’s ratio is appropriate for this area.

3. I have a number of friends that have built many homes for themselves in the same area. After each one is build, they find that the house was not what they really wanted, so they sell and build a new place, hoping that it will be the right one. The error is that the layout of the home was not approached with a recognition of what problems one faces in designing a space. For example, when designing the entrance, it needs to be readily apparent what the entrance is; there needs to be a transition from the inside to the outside; and there needs to be some sort of an entrance room that creates a public space for visitors that is separate from the private areas of the home. This is just one example of many problems in design that must be addressed in the layout of the house.


For more design information, please see Designing a Livable Passive Solar Home

13 comments:

alotodo said...

You might want to visit my website www.SolarHouseProject.com

DJEB said...

Thank you for that link, John or Bruce (whomever it was).

Urban Harvester said...

I have spent the last few years designing passive solar/ zero energy homes in a very hot/ very cold climate. One thing I have found to be critical is to do or have done an energy analysis. The program Energy-10 produced by the US government can be used for this although it isn't particularly user friendly. I often use an energy engineer and my clients always find this a valuable investment (www.heliocentric.org - energy engineer). Best of luck!

DJEB said...

Thanks for the advise, Oliver!

Cleaver said...

I always wondered about the balance between insulation and thermal mass. That seems like where things could go really wrong. I presume the analysis software is the way to do this. You would need some pretty detailed information about the site. Couldn't soil type and moisture level affect the performance of the slab?

DJEB said...

I've read about this software, but what I've read confirms what Oliver said: it's not very user friendly. That turned me off enough that I didn't find out all that it does. Another limitation is that it totally discounts what can be a gain from shade-side windows. In the 90's designer Derek Wrigley from Canberra and I separately came up with the concept of solar reflectors for increased solar gain. (Having a home, Derek was actually able to put this into practice before I could, and he did so back in 1997.) The software cannot count this gain, only subtract shade-side windows (I suspect).

Soil type and moisture could effect the stability of a slab. Slabs are, however, insulated underneath and around their edges. You don't want to try to use the earth as a thermal mass in Ontario. It will be more of a heat drain than a heat sink.

Scott A. Meister said...

I'm liking your design so far, and recognize that it is a work in progress and what you've shown us is to just give us an idea of your approach. I especially love the flow from room to room, and the solar/time-flow design...kitchen to dining to living...public, semi-public-private.

One problematic thing I've noticed with the design of most homes that I've walked through in my lifetime, is that people tend to forget about work and storage space and over-focus on designing for kitchen, dining, living, bed and bath.

I've learned through my own experience, as well as observation of other permaculture properties, that ransitional (i.e. seasonal)work and storage space is especially important for permaculture designers who work with/at/from their home and in their garden. It is also of upmost importance to anyone interested in a sustainable lifestyle...for a sustainable lifestyle requires that a home be productive place, not just a place to eat, sleep and relax and consume.

All permaculture properties that I've seen had multiple projects in progress or in planning or prep stages according to various seasons, future hopes and dreams.

Each project had needs for storage and work space near or around the house...few of them had prepared for such things, and as a result had stuff scattered or stacked up all over the place giving the places a rather un-pleasant, almost "junk-yard" atmosphere at times and in spots.

Seasonal food storage, in-door winter growing space, etc...are also necessary for a permaculture property in a climate such as yours. I can foresee attached greenhouses being a standard thing in the future for all homes in a temperate climate...if not just for passive solar warmth in a cold climate...but for year-round sustainable food production at the home level...I can also see convenient and pleasantly designed thermophilic compost bins included with easy access from both the kitchen and work-shop, maybe even an indoor thermophilic composting room is in order...could help to heat the house in winter!

Just thought these things should be kept in mind...

anyway...keep it up! I can't wait to see the final design implemented someday!

Martin J Frid said...

I like your designs and the thinking is probably very good. I'm from Sweden so I know a bit about the cold. However, living in comfortable, small homes in Japan on-and-off since 1988 has taught me some things about housing. Before you invest in something huge, do consider starting small, and then let the house "grow". Say, 2 rooms and a kitchen at first (with space to add aditional rooms later).

Looking forward to updates!

DJEB said...

Martin, I like your thinking. Cursed be the regulations, however. There is a minimum size that one is allowed to build in Canada, so if you do want a small house, you are out of luck. The design I have here is somewhat larger than you are thinking not only because of the building code, but also because of I will need office and guest space in the home.

Benjamin Pries said...

would it not be prudent to also plant a hedge on the northern side of the house? Where I live, in southern Manitoba, prevailing winter winds come from the North, and they can carry off a great deal of heat. Planting some sort of shelterbelt would help to block the wind and minimize heat loss. Deciduous trees on the south side of the house are also a good idea to shade the house in summer without blocking winter rays.

property in short sale elk grove village said...

The blog was absolutely fantastic! Lots of great information and inspiration, both of which we all need!

Claire McConnell said...

Do you have any thoughts on design for snow? I'm an architect working on early-stage designs for a house in Kazakhstan (yes, really!) and am unfamiliar with design in extreme climates.
A really useful blog with simple and clear points I've largely already incorporated in my design, but now have the words to talk about. Thanks!

DJEB said...

First off Claire, wow! That's a cool project!

The basics in terms of orientation and so on will be the same. If you are dealing with very high snowfall levels, you'l' want a steep pitch to the roof. My house, for example, has a split roof with a 4/12 pitch on the sun side and 12/12 on the shade side. Though the roof is steel, the sun side will accumulate snow, whereas the shade side sheds it rather well.

If your site is in an open spot, drifting might be an issue, in which case windbreaks can help to reduce drifts.

If you have more questions I might be able to help with, I could try and answer them here, or you can reach me via my company site at http://www.ecoedge.ca

Best of luck, and let us know how your project is doing.