Older home on wooded lot
Energy Efficiency, Passive House facts, Passive House resources, Retrofitting Older Homes

Retrofitting an older home to Passive House standard

Next stop in our new series on retrofitting older homes: changes to attain Passive House standard. We have received many requests from readers on how to transform an existing home into a passive home.

Everyone who follows this blog is aware that our mission is to build passive whenever we can. Building to PassiveHouse standard makes the home environment healthy, therefore translating into healthy living. It also makes the world a much healthier place as our dependency on petroleum-based fuels as heating and cooling sources is removed. Finally, a passive house is much cheaper to run. You can think of a passive house as the domestic equivalent of an electric vehicle.

IPHA guidelines

EkoBuilt follows the guidelines from the International Passive House Association. There is a lot of building science behind passive, so it can get very complicated, but it can also be explained and understood very simply. From a build perspective, the world is slowly transforming to become completely passive. Certain areas of British Columbia already mandate the passive standard in order to qualify for a new building permit. It’s important for everyone to understand as it will be here in Ontario sooner than we think.

Passive House Explained in 90 Seconds from Hans-Jörn Eich on Vimeo.

The video was made by Hans-Jörn Eich, a certified Passive House Consultant (Passivhaus Institute in Darmstadt, Germany) and the founder of Pinwheel.

Why does passive house exist?

It’s simple: to replace heating and cooling dependency on gas with electricity. That said, this is only economical if the heating/cooling demand can be reduced to a point where it’s inexpensive to use electricity, and this is where design essentials come into play.

There are three essential design features in a passive home:

1. Air-tightness

It’s vitally important that heat loss is minimized through unwanted and unnecessary leakage of air. We conduct what’s called a blower door test to find the ACH (air changes per hour) a home experiences.

Most newly built homes experience ACH anywhere between 3 and 5, meaning 3 to 5 times the entire volume of air inside the home escapes each hour. This is basically a loss of heated and cooled air which can also result in condensation in the wall cavities, translating ultimately to unhealthy mold.

For newly built passive homes, the ACH rate is 0.6 and the retrofit standard is 1.0.

Old school thinking favoured this air loss, thinking it good for fresh air to enter the building and provide a natural fresh air environment. We now know this is laughable because of all the mold problems we’ve heard about with older homes. To be fair to the old schoolers, in the past, modern building techniques/methods did not exist, nor did heat recovery ventilators (HRVs), so the options didn’t exist to change this approach.

Modern building code recognizes this fundamental change. For example, since 2017 Ontario building code has made HRVs mandatory in all homes, which we were thrilled to see happen. The problem is the HRV is only required to be 50% efficient and most homes are still leaking more air than they should.

2. Thermal envelope

Currently new-build homes, according to the standard building code, are required to have R22 wall insulation, R32 roof insulation and R10 below slab insulation. By comparison, in our local area, newly built passive homes require R75 wall insulation, R110 roof insulation and R40 below slab insulation.

As a general rule of thumb, homes retrofitted to passive standard require R48 wall, roof and below slab (or floor) insulation.

3. Proper windows

For thermal comfort, it’s very important that a passive approved window is used. These are triple glazed units with insulated frames equivalent to an R12. This may not seem like much, but compared to a non-certified triple glazed window, it’s huge. With non-certified units, it’s hard to find a unit above an R4 rating.

Certified windows optimize comfort by having a high temperature interior pane (instead of being cold on the inside when it is cold on the outside). In the passive scenario, this means when it is 25°C outside, the interior pane must be at least 17°C. Non-certified triple glazed windows can be as low as 12°C on the inside under the same conditions.

For those who would like the complete building science, please have a look at the following 20-page document, Criteria for the Passive House, EnerPHit and PHI Low Energy Building Standard (pdf). You can also view four charts at the end of this article.

How can an older home become Passive?

With all of that out of the way, how does an existing home reach the Passive standard?

To be achieved in the most cost-effective manner, this approach will obviously vary depending on the home in question, but some general rules apply:

For the walls: Airtight/vapor tight permeable layers and extra insulation will need to be installed. This will mean that either the interior or exterior finish will need to be removed (the choice will usually depend on which is most cost-effective). Certified windows and doors will also be sourced.

For the roof: If the home has an attic space (most do), extra insulation will be added to that space with an airtight/vapor tight permeable membrane installed on the ceiling side. If there is no attic, then an extra thermal later will have to be installed on the interior. If the ceiling is cathedral in design, it should be simple to build the ceiling down to the required R value. If the ceiling is flat and losing height is an issue, than a vacuum panel will be used to provide a thermal barrier with minimal loss in ceiling height.

For the slab/floor:  If a basement is unavailable/unusable, then a thermal layer will be added to the existing floor cavity. If a basement is present and usable, a vacuum panel will be used to provide the thermal barrier with minimal loss in height.

Interested in making your existing/older home Passive? Give us a shout, we’d love to help you realize that goal.

You may also be interested in our blog post on taking a staged approach to retrofitting your older home.

Ottawa passive house
EkoModel News, Passive House resources

EkoModel Open House – This Weekend!

The transition from winter to spring has made our laneway a little interesting, but we’re happy to say the Open House is very much on!

Spring EkoModel Home Open House
96 Libbys Road, McNab/Braeside, ON K7S 0E1
Sat, April 6, 2019
9am – 3pm

Come on out to experience a passive house, ask your questions and just generally get a chance to see the quality of work done by EkoBuilt.

We had more than 100 folks out in January and look forward to meeting many more of you this weekend!

A rocking chair in a room of the EkoModel Home
EkoBuilt News & Happenings, Passive House resources

EkoBuilt Open House this Saturday

We’ve had tremendous feedback on our Open House at the EkoModel Home this Saturday, 26 January 2019. Paul Kealey is already fully booked for conversations with some of you throughout the day; if you haven’t snagged a time to speak with Paul, don’t worry, there is still much to come out for:

  • 12.30 – 1pm will feature a presentation on sustainable home building by a team from Algonquin College
  • The whole day will be a super opportunity to look over and feel what it’s like to be in a passive home built with care and quality materials
  • If you’re lucky, you may get a few minutes to speak with EkoBuilt’s Paul Kealey, but if not don’t worry, you can follow up with a phone call or arrange a meeting. EkoBuilt will also be an exhibitor at three shows in Ottawa this spring and will run another Open House at the EkoModel Home in April.

EkoModel Home Open House
Sat, January 26th, 2019
9am to 3pm
96 Libbys Road
McNab/Braeside, ON K7S 0E1

Please come to feel and see for yourself the incredible comfort of a beautifully built Passive House.

EkoBuilt’s demonstration PassiveHouse was built on a 10-acre property just west of Ottawa during 2016. This 2,506 square foot home includes 4 bedrooms, 2 1/2 bathrooms, and beautiful, sun-filled rooms.

Spring 2019 Trade Show Schedule

Come out to see the EkoBuilt team and offerings at these shows in spring 2019:

EkoBuilt passive house
EkoBuilt News & Happenings, EkoModel News, Passive House resources

Sat, Jan 26th next EkoModel Home Open House

One of the top questions we regularly receive is when our next Open House will be at the EkoModel Home, our passive house demonstration property (4 bedrooms, 2.5 bathrooms, 2500 sq ft) just west of Ottawa. Mark your calendars!

EkoModel Home Open House
Sat, January 26th, 2019
9am to 3pm
96 Libbys Road
McNab/Braeside, ON K7S 0E1

Please come to feel and see for yourself the incredible comfort of a beautifully built Passive House.

EkoBuilt’s demonstration PassiveHouse was built on a 10-acre property just west of Ottawa during 2016. This 2,506 square foot home includes 4 bedrooms, 2 1/2 bathrooms, and beautiful, sun-filled rooms.

EkoBuilt News & Happenings, Energy Efficiency, Passive House facts

International Passive House Days 2017

Passive House residents around the world open their doors Nov 10th – 12th, 2017. The EkoModel Home near Ottawa will open its doors after having been lived in for a year, so this is a great time to visit our project and check out others in the area.

Get first hand experience of the many advantages Passive Houses offer, and feel the supreme comfort of these super energy efficient homes.

Find Homes Near You

The EkoModel HomeTo search on participating homes in Ottawa, Eastern Ontario, or wherever you live, use the Passive House Database.

The listing for the EkoModel Home, including its passive house credentials, can be found at listing 5081 on the Passive House Database.

Please come out and visit our four-bedroom, 2,509 sq ft passive house on any of the following days:

Fri, 10 Nov: 9-3pm
Sat, 11 Nov: 9-3pm
Sun, 12 Nov: 9-3pm

See complete house plans for the EkoBuilt Trillium passive house right here.

See all 13 of our Passive House plans here – we can modify any of these plans to best suit your needs!

EkoBuilt's passive house solar engine
EkoModel News, Energy & Household Trends, Energy Efficiency, Passive House facts

Reflecting on a warm winter in the EkoModel Home

The sub-title for this post really should be “how comfortable is a passive house in winter?” And the answer is: very!

Okay, so the sun has been shining and we’re feeling the summer’s warmth, but cast your mind back to the long, grey winter we had here in the Ottawa Valley. Not for long, just long enough to picture the environment in which the EkoModel passive house spent its first winter.

Although the average temperature for the area was roughly -5.5C from December through March, December and January both saw some supremely cold days: -28C the low in December, -25C the low in January. Throughout the period we kept the house at steady 21C for daytime and evening; overnight, with no heating, the temperature would make a gentle fall to 18 or 19C by morning.

Having lived in homes in the past where keeping the temperature at 21C would have been too costly, this round the clock comfort was the revelation we hoped it would be. Both floors of the home, including the upstairs bedrooms, maintained these temperatures – no ‘cool spots’ as in many older homes.

The Eko Solar Engine - passive house infographic

Click to learn about the EkoBuilt solar engine that heats (and cools) this passive house

All of this was achieved using an average of just 31.75 kWh per day – which may not seem that low, until you remember that this passive house has NO FURNACE. That hydro-electricity usage simply represents the operation of the ‘solar engine’ components (including a fresh air exchanger, and an air-to-air heating and cooling pump) of the house, and daily living (lights, cooking, heating water*, PC and television usage) of a family of five.

So, our total energy bills for the four deep winter months was $801.48 (or $200/month).

*We heat our water to 120C.

An interesting note on Sunny Days

If it was a sunny day and we had approximately six hours of sun or more pouring through the south facing windows, we did not need to use the heating system at all.

The sun had no problem raising the temperature of the house from 19°C in the morning to about 24°C in the afternoon, in which case the temperature would drop to about 22°C in the evening and hover at about 20°C in the morning. Amazing!

 

What we’ll do differently next year

Overall, the house performed as expected, and the very low energy usage (seen here) and bills, even in a cold, grey winter, are great practical evidence. Less easy to share, but no less significant, is the supreme comfort that we enjoyed all winter long.

Hydry usage for the EkoBuilt passive house in winter 2017

Looking ahead to next year, we’re considering installing an ethanol (biofuel) fireplace. These units are a very simple and clean alternative to wood burning fireplaces and woodstoves, and their benefits are amplified in a passive house, where much less heat input is required to warm the home, and a fresh oxygen supply with good airflow is continually available.

There is a great overview of ethanol fireplaces on Houzz, and again we’d underscore the greater benefit to a passive house over a conventional build. In brief, this heating method has a very small environmental footprint, is low maintenance and attractive. We see this heat source as a great alternative when sunshine is severely limited, as it was this past winter in the Ottawa Valley. Any successful system has a built-in backup, and this looks like a great way to round out the solar engine that is driving our passive house.

Questions about the passive house performance?

If you have questions or thoughts about our passive home’s winter performance, please do feel free to comment here or contact us. We’re keen to share this information as clearly as possible in order to help homeowners to understand the huge benefits of building a passive house.

EkoModel News

Join us at Green Energy Doors Open!

Ready to see the EkoModelHome? EkoBuilt will be taking part in Green Energy Doors Open ’16 this coming weekend. As described on the event’s website:

Green Energy Doors Open, is a province-wide, year-round communications campaign and showcase of individual, community, and commercial sustainable energy projects. It is organized and spearheaded by the Ontario Sustainable Energy Association. The initiative aims to showcase advancements in the sector, demonstrating that Ontario is already on the path to building a 100% clean, sustainable energy system.

At the time of the event, the EkoBuilt Model Home will be nearly complete, with all but exterior siding and landscaping, making it a fantastic time to see the house. Other passive house projects in the Ottawa area will also be on the tour, making for a great weekend focused on sustainable home building.

Save the Date

EkoBuilt’s Doors Open Hours & Info
9 – 11 September 2016
9am to 5pm

EkoBuilt News & Happenings

New pricing and approach to EkoBuilt’s passive house kits

We’ve made some fundamental changes to how we price and deliver our Passive House kits, and here’s why:

EkoBuilt’s goal is to provide anyone building a new home the opportunity of achieving an affordable Passive House. We know that this looks different for everyone.

Foxglove cottage kit plan

Foxglove, 1424 sq ft
Total sample build cost: $337,130. See cost analysis >

Our challenge: The Passive House model, although a simple approach to construction, does require specialized carpentry and building techniques. It has three simple but crucial layers to the building which need to be properly sealed. There is a watertight layer, a wind tight layer, and a vapour tight layer which, when installed properly, easily ensure that the house will perform to the passive house standard.

Our solution: We have simplified our passive house materials package to include all items necessary for a watertight, wind tight, and vapour tight passive house. We are excluding previously included items such as exterior siding, soffit/facia, steel roofing, timber frame, insulation because these items are readily available anywhere in Canada. Doing this allows the home builder much greater flexibility and control over the total project budget.

Why it matters: Our revised passive House material package is important to the consumer in three key ways:

1. For the Do-it-Yourselfer
Because all of the materials necessary to build a watertight, wind tight and vapour tight passive house are available in a single package (including design plans), there is no need to undertake the extensive research and sourcing to figure this out. We have done the hard work for you and in a single phone call or a meeting with one of our representatives we will prove to you that our system is the most cost effective and affordable system on the market.

Sometimes the building permit process alone is burdensome enough to prevent an individual from building their own house. In addition to construction drawings most building departments are now asking for duct design, heat loss calculations, an engineer’s stamp, energy efficiency design summary, etc. EkoBuilt is a registered design firm and in addition to construction drawings (which have always been included with our packages), we are now including all of the paperwork required to satisfy any building department’s requirements. We believe the permit process should be simple and free of headaches and we’re doing all we can to aid in this process.

2. For the small builder or contractor
For the builder/contractor who has a client interested in passive house or just generally wants to offer passive house to clients, this approach is superb. Although passive house is known and understood by many Canadians it is still a relatively new style of building in our country. Therefore most consumers and builders have limited knowledge of proper passive house design specifications and materials, particularly windows and doors.

EkoBuilt is not only specialized in passive house design and construction; we are committed to making the affordable passive house a reality. We have placed all of the necessary materials into one simple package and can offer support, if desired. Our simplified package also provides the builder or contractor with the ability to supply and build most of the house on their own, including exterior siding, roofing, fascia/soffit, interior finishes, etc.

3. For the owner-builder who wants to act as their own general contractor
Many of our clients prefer this approach because they like to choose interior finishes and be completely involved in the decision making process, but it would be beyond them to put together a passive house materials and design package. This is our specialty and we are committed to using the best materials that are also affordable, making it unnecessary for owner-builders to get tangled up in research and complex decisions. Just give us a call and we will explain everything:  we want our clients to be completely aware of and confident in the specific materials used and the reasons behind their selection.

How do you want to build your new home?

Over the years, we have encountered every possible variation in home owner involvement in the new house building process. We understand that you need as much information as possible, particularly on every aspect of building a realistic budget for your project. We also understand that everyone comes at the process differently.

For this reason, we can:

  • Just provide you with one of our 13 passive house plans and materials kits.
  • Provide you with one of our kits, along with additional support and/or services.
  • Build your new passive house from start to finish, including to a completely unique design of your own choosing, or by modifying one of our existing designs to better suit your needs (site requirements, lifestyle needs, etc.).

We can supply and install exterior siding, roofing, fascia/soffit, interior finishes, HRV, kitchens, etc. We have simplified the basic Passive House materials package so that anyone can achieve this standard in an affordable way, but we’re still here to provide a total solution from design through to the installation of the last finish in your new home, if that’s what you’d prefer. Call us today to find out more.

Quick links

PassiveHouse Plans & Prices
PassiveHouse Materials
EkoBuilt PassiveHouse Cost Analysis
PassiveHouse Gallery

House Design, Passive House resources

Why a low slope roof makes sense

Southern elevation of Ottawa passive house by EkoBuilt

EkoModel Home – southern elevation

The EkoModel Home was designed with a low slope roof, a smart feature shared by all 13 of EkoBuilt’s passive house plans.

This style of roof greatly reduces construction costs, and also introduces great strength and stability, which is a tremendous benefit in our part of Canada where snow loads in the winter can be incredibly deep and heavy.

While a standard cathedral ceiling roof rafter is required by current code to be 12 inches deep to carry snow loads, our passive house rafters are 30 inches deep. The depth originally designed for increased insulation (typically three times that for a conventional build) lends amazing strength for those snow loads.

As Europeans – who have lived with high utility costs for many years – understand innately, a low slope roof offers tremendous cost savings in the long run. North Americans are only just starting to come around to the wisdom of this roof-style, as they realize how important reducing energy costs will be the further we move into the 21st century.

A number of key factors go into an effective low slope roof, including the following:

Roofing underlayment

As part of our standard PassiveHouse package, we include the installation of a high temperature ice/water membrane which completely waterproofs the roof and is guaranteed for 50 years. It is specifically designed for low slope roofs as low as 0.5 inch (2 1/2°), and is able to withstand temperatures of up to 121°C!

The membrane that we use is WinterGuard HT Advanced Waterproofing Underlayment by CertainTeed. For more detail:

See product details on CertainTeed’s website.
Review the WinterGuard HT brochure [pdf]

Roof cover

Another important factor is to reduce the heat island effect by making use of cool roof technology. The term “heat island”describes built areas that are hotter than nearby rural areas. The annual mean temperature of a city with 1 million people can be 1 – 3°C warmer than its surroundings. By the evening this difference can rise to around 12°C.

Heat islands can affect communities by increasing summertime peak energy demand, air conditioning costs, air pollution and greenhouse gas emissions, heat related illness and mortality, as well as water quality.

High solar reflectivity [albedo] is the most important characteristic of a cool roof as it helps to reflect sunlight and heat away from a building. Cool roof technology can reduce a roof’s temperature by 28 to 33°C during summer weather.

More information

Information on Heat Islands (US Environmental Protection Agency)
Using Cool Roofs to Reduce Heat Islands (EPA)

Wakefield Bridge steel shingles

Click to enlarge image

We chose to use Ideal Steel’s Wakefield Bridge Steel Shingles because they have the most advanced cool metal roof technology we could find. The special resin paint system used results in a high albedo factor; there are a range of colours available.

Added benefits of Wakefield Bridge Steel Shingle roofing:

  • Manufactured from recycled and new steel
  • 50 year warranty
  • Cost-effective at approximately $2 per square foot

More information

Product brochure for Wakefield Bridge Steel Shingles [pdf]

Soffit and fascia

passive-house-roof-soffit

Click to enlarge image

Finally, additional roof finishes include aluminum soffit and fascia, chosen for being inexpensive, clean lines and excellent ventilation properties for a steel roof.

Together, all of these elements work together to make for a high performance, low cost roof that will help to keep more money in your pocket now, and in the future.

EkoBuilt is here to help those who are thinking a little ahead of the curve to maximize their home’s beauty while making the most of its energy efficiency and comfort. Get in touch to find out more.

Passive House facts, Passive House resources

Insulation in a Passive House

Blown cellulose insulation around doorsOne of the keys to the super low energy footprint of a Passive House is abundant insulation. But not just any insulation will do.

For the EkoBuilt Model Home, we chose Thermocell’s ProCell Blue, a blown cellulose insulation that makes use of wood fibre.

ProCell Blue uses 100% post-consumer recycled content. It also contains naturally occurring, non-toxic borate (familiar to many in Borax, the natural detergent) which makes the insulation completely fire retardant, eliminates the risk of mold/mildew, and repels insects. A perfect choice for a healthy home.

The method of installation insures that the insulation is very densely packed, eliminating any possibility of the insulation settling and creating air pockets.

Interested to learn more? Find out more about what makes a PassiveHouse so efficient and comfortable on our Ottawa Passive House Design & Construction page.