Homesol on Twitter


Click above to "like" Homesol

Documentary on Passive House shows 90% less energy, 0% more cost

Homesol wins EnerQuality Evaluator of the Year Award!







 Energy design specialists
for sustainable green building


High performance homes make a world of difference. Healthy, durable, efficient and Earth-friendly building is the way of the future. From ENERGY STARR-2000 and LEED, to Passive House, Zero Energy+ Homes and Deep Energy Retrofits: Call in the team of green building consultants at Homesol Building Solutions, we’ll get your projects there today! 


Homesol’s dedicated team of advanced building performance specialists deliver fast, accurate, cost-effective and hassle-free energy design solutions throughout North America, inspiring builders, contractors, designers and owners to create energy-efficient, comfortable, sustainable and economical-to-own residential and commercial buildings. Count on Homesol's decades of experience for your green building projects.

Homesol offers the following services:


All new build & retrofits must be carbon neutral

"It’s not an add-on, and it's not an exception. It's not an exemplary standard that others can aspire to, but not meet. It's got to be — literally — the standard. All new build has got to be carbon neutral. And also in terms of existing build, we've got to retrofit to a standard of being energy neutral and ideally being energy positive." 

Brendan Halligan, Chair of the Institute of International & European Affairs, and of the Sustainable Energy Authority of Ireland


Radon, Silent Killer?

Not if you have an alarm in your basement!

By Ross Elliott, LEED-AP, CPHC
President, Homesol Building Solutions

It was a quiet beeping, sort of like a watch alarm, and at first I couldn't quite place where it was coming from. The sound led me to my radon detector, which was showing a truly alarming 1,456 Becquerels of radioactive gas in my basement!

In Canada, the government has set 200 Becquerels as the maximum "safe" level of radon, so my house was positively glowing with radiation, at more than seven times over the danger limit. But my radon monitor had never shown such high numbers, what had changed to make my house so radioactive? The answer was easy and I'll get to that soon, but let's talk about why I have a radon monitor in my basement in the first place.

I was in Winnipeg a few months ago speaking to the Manitoba Building Envelope Council about Passive House, on the coldest day of the year, of the coldest winter in 75 years (some underground water lines in the city are still frozen!), which is where I met Eric Bjornson. Eric was my gracious host and guide for MBEC, and he also happens to be a radon remediation expert , operating a business called Radon Matters . Over a pint at McSorley's Old Ale House, Eric told me about an electronic radon detector that is as accurate as the mail-away canisters. For someone like me who apparently lives right on top of a uranium deposit, this gadget was perfect, so I bought one from him, the best $140 I've spent in a long time.

Radon kills three thousand Canadians every year, like wiping out 2/3 of Almonte's population over and over again, or a fully loaded plane crashing every month (the Canadian government's official statistic is that "only" 1,900 people were needlessly killed by this entirely preventable odourless, tasteless and invisible indoor air quality hazard in 2006, so it's certain there were over 2,000 radon deaths this year, but let's not quibble over exactly how many preventable lung cancers there are every year, let's ask how many are acceptable!).

Radon is the second leading cause of lung cancer after smoking, as well as the primary cause of lung cancer deaths among non-smokers. It more than triples a smokers chance of dying from lung cancer. At least 10% of all homes in Canada have highly carcinogenic levels of radon, putting more than 2.4 million people at risk. A friend of mine in Perth had the love of his life die of lung cancer in the prime of her life, despite never having been a smoker, and radon is most likely to blame. Yet all of this unnecessary suffering and early death is entirely preventable simply by following a few guidelines that every builder, renovator or homeowner should consider if there is any chance at all their home may be located in a radon-susceptible area (which means most of Canada, as this map from shows!).

As this graphic from the US Environmental Protection Agency  demonstrates, installing a radon pipe is really quite simple:

  • Install 4" of clean stone
  • Install a 3" ABS plumbing T in the stone, with two horizontal perforated 10' septic bed pipes running off it, and one pipe running vertically through interior walls, out through the roof like a plumbing stack
  • Create a continuous airtight seal under the slab and footings with min. 6 mil. poly
  • Seal any cracks or expansion joints in the concrete slab
  • Provide exhaust ventilation from the basement with a balanced heat recovery ventilator
  • Test for radon for one year once the house is airtight and occupied. If it exceeds 100 Becquerels then install an in-line fan in the attic (which is why you pre-wired a junction box there) with a speed controller, to continuously depressurize under the slab (only 5 Pascals or less of negative pressure is needed to rid the house of radon).
  • For existing homes, check out Reducing Radon Levels in Existing Homes: A Canadian Guide for Professional Contractors

Why aren't radon mitigation measures and / or radon monitors mandatory in all affected homes, if it can save thousands of lives? Surely it can't be about money, since most people would gladly trade a few hundred dollars extra on the cost of their home for spending even one day dying of lung cancer! From what I can tell, it's the real estate lobby who are against introducing legislation to keep Canadians safe.

Now back to why that radon alarm in my basement went off and what I did about it.

Kathryn and I live about half an hour from Sharbot Lake, you may remember a standoff there a while back between uranium mining interests and Algonquin land claims, and out here in Lanark Highlands our Canadian Shield granite is riddled with radioactivity. Before I started renovating our 1930s farmhouse, I tested for radon and it came out more than four times higher than the safe level, at over 900 Becquerels. After following the CaGBC guidelines and installing powered subslab ventilation, our radon readings in our renovated house were always below 60.

A couple of weeks ago, I turned off the sub-slab radon ventilation fan to save the minimal 13 watts of electricity it uses on medium speed, reasoning that in mid-summer the house is well enough ventilated with open windows that we don't need to worry about radon. It was a few days later I heard the beeping from my Pro Series 3 Radon Gas Monitor warning me of dangerous levels of radon in the house, almost 1500 Becquerels - without a wintertime temperature difference, the passive vent stack wasn't working at all! So I simply turned the sub-slab ventilation fan back on, and within three days we were back to well below World Health Organization guidelines of 100 Becquerels.

So why on Earth doesn't every house at risk have the ability to detect cancer-causing radon, and eliminate it instantly with the flick of a switch? It's so easy and cheap to do, it's a no-brainer even though Code doesn't require sub-slab radon venting - yet. Radon kills, and the solutions are simple. Homesol is here to help! Give us a call if you'd like our assistance, or to borrow our radon monitor.

For more information on radon and what you can do about it, check out Health Canada's website at and the US EPA's site at


Code Update: Fully Insulated Basements Are Coming Soon

Best Practices for Insulating Slabs & Footings

By Stephen Magneron, CPHC
Advanced Housing Specialist

Insulation under the slab is one of the most overlooked strategies in most homes built today. Not only does it help create a warm, dry, comfortable basement, but it will also save on heating bills.

Slabs can be from 10% to 30% of the heat loss surface area of a home, with townhomes on the lower end to sprawling bungalows on the higher end. Admittedly, the heat loss is less than that of the roof or the above grade walls that experience higher temperature difference between the indoors and outdoors. However, the ground’s constant temperature is around 10oC in the Ottawa area. Imagine if the temperature outside was 10oC all year round, 24/7, and your house was uninsulated. You would be either very uncomfortable or paying 24/7 to keep the indoor temperature at a cozy 20oC. It truly makes little sense that we've been upgrading all our other thermal assemblies yet commonly leave such a large portion of our building envelope completely uninsulated!

So why is slab insulation consistently being overlooked?

The ENERGY STAR standard v12.3 does not require insulation under the slab as a core requirement. However, it does recognize the benefits of this strategy, and encourages builders by awarding Builder Option Package (BOP) points for R-5 (0.1) or R-10 (0.3) installed continuously under unheated slabs.

Under heated slabs, the core requirement introduces a minimum of R-13.2, which is not eligible for any BOP points. The reason for this is the slab is a heating source, therefore there's a much higher temperature difference to the ground. Sure, some heat will radiate into the room, but a significant amount would be lost to the ground in the absence of insulation. Clearly not very energy efficient!

When modelling a home in HOT2000 for ENERGY STAR Performance Path or R-2000 homes, or in the Passive House Planning Package (PHPP) for Passive House projects, the amount of insulation required will be based on analyzing the effects of different levels of insulation. This can range anywhere from R-10 to R-50 for a Passive House that is trying to squeeze out as many kWh of space heat demand as possible. For a heated slab our recommendation is a bare minimum of R-30, and no less than half that under any unheated slab.

The installation of the insulation under the slab is most effective with multiple layers of foam so that their joints are staggered. It is also critical that it connects to the basement wall’s insulation. Typical strategies were discussed in the last issue of the newsletter “Basement Insulation: Myths and Realities”. The idea to keep in mind is that you want to create a thermal bridge free connection at the perimeter of the slab. For example, if the basement wall is insulated to the inside then the slab insulation should be installed above the footing and must include a thermal break at its perimeter with an equivalent R-value. If the basement wall is insulated to the exterior, then the slab’s insulation strategy must also include wrapping the footing with the same amount of insulation so that it connects with the exterior insulation. This is a very effective strategy, but a little more costly, and requires a bit more planning. The foam under the footing, for example, will need to be high density foam that is rated to take the load of the building. The beauty of this strategy is that the structure can be completely enclosed with insulation, keeping it warm and dry.

The benefits of slab insulation for homeowners are undeniable – comfortable, warm and dry, with no more of that "basement odour". The benefit for builders is that it represents another option to ENERGY STAR and happier clients because they are more comfortable in their basements. When builders, buyers and code officials finally understand the numerous merits of slab insulation, you can be sure it will not be overlooked in the future!

Tech Corner: ENERGY STAR® for New Homes & Above Grade Wall Assemblies

By Abbie Coates, Building Performance Specialist

In ESNH version 12, the minimum insulation requirement for all above grade walls (including tall walls) has increased. The insulation level is now measured relative to the wall's Effective R-Value, taking into account the thermal bridging of a stud wall which reduces the overall effectiveness of the cavity insulation. For example, consider a base wall assembly made up of vinyl siding, OBS sheathing, 2x6 wood studs @ 16" o.c. with R-22 batts and gypsum board. This assembly has a Nominal R-value of R-22 and an Effective R-value of R-17.


Minimum Requirement

The minimum Effective R-value in walls above grade is now R-17.5. Our base wall assembly (2x6 R-22 batts @ 16" o.c.) does not meet this requirement and would need to be upgraded either by adding a higher insulation level in the cavity, increasing the stud spacing and/or by adding continuous insulation.  The following 4 examples all meet the minimum ENERGY STAR requirement.

  • 2x4 R-12 batts @ 16” o.c. with R-7.5 rigid board (Effective R-18.5)
  • 2x6 R-22 batts @ 24” o.c. (Effective R-17.7)
  • 2x6 R-24 batts @ 16” o.c. (Effective R-17.7)
  • 2x6 R-22 batts @ 16" o.c. with 1/2" fibreboard (Effective R-17.7)

Of course there are many more ways to meet the minimum specs, Homesol's energy evaluators can help you find the best options for your homes.

Earning Builders Options Package (BOP) Points

In the BOP, there is the potential to earn quite a few points for increasing the insulation levels of the Above Grade Walls. Using our base wall assembly from above, with R-17 Effective R-value, we could add a layer of continuous insulation (e.g. XPS) to the exterior of the wall.  This would increase the Effective R-value by the value of the Nominal R-value of the insulation because no thermal bridging occurs with continuous insulation. For example, just adding R-4 rigid board insulation to 2x6 R-22 @ 16" o.c. would increase the effective R-value to R-21, earning 0.8 points on your BOP!  You can earn up to 1.7 points for adding more insulation to your walls (and you might as well get used to it now, since building codes are going there soon!). For more examples of wall assemblies that earn BOP points, click here.


Garage Wall Buffer

In version 12.3, a buffering effect has been included for walls between the home and an unconditioned garage (or sun porch, veranda, etc.).  This wall is considered to be sheltered from direct heat loss to the exterior air, which is estimated to have the same effect as adding a layer of R-0.9 continuous insulation to the wall.  Looking at our base wall assembly example (2x6, R-22 @ 16" o.c.) which has an Effective R-value of R-17.0;  If this wall assembly is used in a garage wall, then the Effective R-value would become R-17.9 which now meets the ESNH minimum requirement!


Tall Walls

Currently, other than the Garage Wall buffer, there are no other exceptions or aids for wall assemblies.  If there is a structural requirement to reduce the stud spacing of a wall (e.g. for tall walls), this will reduce the Effective R-value of the wall.  Reducing the stud spacing of a 2x6 wall with R-22 batts from 16" o.c. to 12" o.c. would decrease the Effective R-value from R-17.0 to R-16.7.  To bring the Effective R-value up to the required value, one of the following wall assemblies could be used:

  • 2x6 R-20 batts @ 12" o.c. + ½” polyiso board air/vapour barrier  (Effective R-18.9)
  • 2x6 R-24 batts @ 12" o.c. with two layers 1/2" drywall (Effective R-17.8)
  • 2x6 R-24 batts @ 12" o.c. with 1/2" fibreboard (Effective R-18.1)
  • 2x8 R-28 batts @ 12" o.c. (Effective R-20.9)

Again, there are numerous other assemblies possible.

Based on the upgrade cost from 2x6 R-22 batts, it appears R-22 + polyiso on the interior, or R-24 + fibreboard on the exterior are the clear winners, and both have highly advantageous hygrothermal properties. The foil-faced polyisocyanurate foamboard on the interior makes an excellent vapour barrier and primary air barrier, while fibreboard is so permeable on the exterior it's virtually invisible to water vapour. Either material helps ensure your wall assemblies stay dry.

Future revisions to the ENERGY STAR specifications may include provisions for averaging the effective R-values of all above grade walls, which may allow for less effective insulation in tall walls, but only if other walls exceed the minimum. As of this writing there has been no discussion of any amendment and NRCan confirms ENERGY STAR tall walls must meet effective R-17.5.


A New Tool for your Tool Belt

A free Tool is available on-line from the Canadian Wood Council that will calculate the Effective R-values of Above Grade Wall Assemblies. Click here to access the Wall Thermal Design Calculator.

For more information on ENERGY STAR above-grade wall assemblies, contact Abbie Coates at Homesol.


ESNH Builders: Are ES furnace changes affecting your new homes?

By Abbie Coates, Building Performance Specialist

It’s recently come to our attention that some furnace manufactures have discontinued having their units ENERGY STAR-qualified. 

This poses some concern for homes enrolled in the ENERGY STAR for New Homes (ESNH) program, as an ENERGY STAR-qualified furnace may be required for certification. 

Here’s a summary of the ESNH requirements for furnaces: 

ESNH – version 2011 (which will end in November 2014)

ESNH – version 12 (known as the 2012 version)

Min efficiency 92% AFUE ENERGY STAR-qualified, and

ECM motors qualify for an Electrical Savings Credit

Min. efficiency 95% AFUE and either

1) ENERGY STAR-qualified, or

2) With furnace fan efficiency ≤ 2.0%


ENERGY STAR-qualified furnaces are listed on this website:

(NB: this is a US website, so be sure to check off Canadian) 

A list of furnace specs is available here, but ENERGY STAR information is not provided):

Please feel free to contact us if your ENERGY STAR homes have been impacted by this change, and we’ll help you get it corrected so you can continue to build cost-effective, high-value ENERGY STAR homes!