Part 4: Problems with the City of Vancouver Zero Emissions Building Plan- 4 of 4

The Passive House Part of the Plan

Key to the City of Vancouver's new Zero Emissions Plan is a heavy focus on the building envelope and conversely the Passive House standard (which uses EUI or Energy Use Intensity as their standard).  There is also a new Thermal Energy Demand Intensity (TEDI) envelope and ventilation target which functions much the same way as Passive House, so for this post we need not focus on TEDI. If they adopt either of these standards they will be the first municipality in North American that will trade an energy efficiency standard for one based on intensity. Make no mistake, TEDI and EUI are not a measure of energy efficiency and efficiency is what anyone working in green buildings would say is of most value.

Passive House is a standard very similar to Natural Resources Canada's R2000 program that focuses on air tightness and heavy on insulation values. These basic elements of air tightness (along with poor detailing and builder unfamiliarity) led to the leaky condo crisis that struck much of Ontario and BC because as an envelope consultant on one of our projects once put it;

Air tightness is a double edged sword. While sealing an orange inside a zip lock bag will likely keep the cold air out of the bag, it seals in the moisture and that orange rots much faster than if you hadn't put it inside the bag.

Make no mistake, we feel that the building envelope is important. Almost all building energy standards put a focus on building envelope efficiency including ASHRAE, the Model National Energy Code and others. However we question the merit of a standard the focuses so heavily on building envelope without accounting for indoor air quality, mechanical equipment effectiveness etc.

What is Passive House

To have a Passive House certification, a building has to meet three criteria. The first is that a building has to be completely airtight to ensure no hot or cold air are escapes, cutting down on energy needed for heating and cooling. The second is the annual energy consumed for heating and cooling must not exceed 15 kWh/sm/year (EUI measure). Thirdly, the total energy consumed must not exceed 120 kWh/sm/year.

Issues with Passive House

1. Overheating
The standard comes from Germany, designed to perform effectively and efficiently in a temperate European climate. Cooling a Passive House can also be difficult, and overheating is often a reported problem with the standard. It's a little like wearing a winter parka year round. In an article published by the New York Times, Joseph Lstiburek, an engineer for the Building Science Cooperation reiterates the extreme differences of climate in North America that the German model doesn’t take into account. He says that

[they] don’t know how to do air conditioning or [deal with] humidity.

2. The mechanical system and indoor air quality

For some context the number of air changes per hour (ACH) on a hospital (per CSA requirements for contamination control) is 10 ACH. That means every hour a space will get a complete exchange of stale indoor air for fresh outdoor. This helps control contaminates and makes for very good indoor air quality. In Passive House the building can have no more than 0.6 ACH. While we recognize that a home is not a hospital, most people would likely choose good air quality over potential energy savings.

The mechanical system used in Passive House (Heat Recovery Ventilation systems) can pose some challenges. Evert Hasselaar, Ph.D., professor of Environmental Engineering, and researcher of sustainable and healthy housing states:

That certain health complaints are more prevalent with heat recovery ventilation systems. The percentage of health problems almost doubles in every case compared to a conventional mechanical exhaust system.

These health issues could be in part due to the condensation and mold build-up that often appears in HRV systems filter. HRV filters need changing every 6-12 months, which is often overlooked. It’s not necessary a criticism of HRV’s but more likely a result of unfamiliarity within the residential sector where most people are used to operating a very simple boiler.

HRV systems would also only be saving the average Vancouver building a few hundred dollars a year in energy costs. Green Building Advisor Martin Holladay recognizes this, stating:

When implemented in North America, often [the] results are buildings that aren’t cost-effective. These Passivhaus buildings have insulation that is so thick, and windows that are so expensive, that the cost of the insulation and window upgrades is much higher than the value of the energy that will be saved by these upgrades over the life of the building.” Compared to “places with expensive energy, everything was affordable in a sense: even [envelope] measures that were deep into diminishing returns still showed cash flow. In places with cheap energy, distressingly little was affordable.”  Building owners and occupants likely won’t see a reimbursement during the building’s lifetime, and it may be hard to get stakeholders on board with Passive House. 

3. More diminishing returns on investment in Vancouver
In Vancouver, building a Passive House would likely have a very long return on investment. Vancouver has one of the mildest climates in North America (both a low heating load and a very low cooling load). The National Energy Code and ASHRAE rarely set the R value in their standards to higher than about R-15 as the value of insulation after R-15 is pretty minimal.

Insulation is Good Investment Up to a Point

4. A portfolio tool used as an energy standard

One part of the Passive House energy standard that is particularly problematic is the use of EUI (Energy Use Intensity) as a design target. Energy Use intensity has risen in popularity because it is a simple single number that can be easily remembered. For Passive House it's 120 kWh/sm/year. The problem with EUI is that as a measure it is only really useful for portfolio management. If you had 20 houses all the same size with the same number of people in them, then a house using 400 when the rest are using 120 means that something is wrong with the house using 400.

The challenge with an intensity number is that the same drop of energy (kWh) in a big bucket (square meters or sm) can make it look like a building is energy efficient. If we do a 100 sm (about 1,000 square feet) Passive House with a family of 3 in it and the total energy use is 12,000 kWh a year then this house meets the standard of 120 kWh/sm/year. But now we take a McMansion of 1,000 sm (or 10,000 square feet) with a single home owner who is rarely home and their energy use is 10 times that of the family of three and his EUI is the same he also complies with Passive House.

The Problem with Intensity Measures

Conclusion

The negatives of Passive House or any envelope focused standard seem to outweigh the benefits in Vancouver. The scope of Passive House’ regulation is limited and rigid compared to LEED certification which gives flexibility to achieving energy efficient buildings. The City of Vancouver cannot disregard the importance of water savings, material selection, transportation and location requirements that their current standard takes into consideration to improve overall sustainability.

We would recommend staying with the current standard and applying it to more building types or increasing the efficiency threshold for each building type. Right now for rezonings of part 3 buildings, a project needs to be 22% better than ASHRAE. Making that a requirement of non-rezonings or increasing that value is likely going to be much more effective than changing to a standard that is not focused on energy efficiency.

The industry is familiar with ASHREA. In fact the standard is the duty of care for design that all engineers in North American are held to. It addresses energy efficiency, domestic hot water etc and has been very effective throughout it's 41 years in practice. The CaGBC and USGBC (and their partner ASHRAE) all use the City's current standard and we are sure would work as effective partners to continue to further drive down GHG in the City of Vancouver. 

While there is no perfect solution to reducing our environmental impact, Passive House and the rest of the Zero Emissions Plan is certainly not the best choice for Vancouver to lower it's greenhouse gas impact. 

Part 3: Problems with the City of Vancouver Zero Emissions Building Plan- 3 of 4

What does zero emissions mean and what are the challenges?

While zero emissions sounds like a simple concept it's actually a pretty tricky discussion with lots of different terms being used for an array of reasons. As with many things the devil is in the details. The simplest technical thing to keep in mind is that not all emissions are equal. In the conversation about greenhouse gases (which are the emissions we want to have become neutral) we have to understand a concept of CO2 equivalent. What this means is that there are multiple gases that contribute to global warming (i.e. greenhouse gases or GHGs). They are all called CO2e because everything is compared to CO2 in terms of it's impact on the greenhouse gas effect. If CO2 effects the greenhouse gas as a 1 (since it's the baseline) then methane would effect it at about a 25 and nitrous oxide at 298.

The relevance for this discussion is that as things like the tundra thaw and release massive amounts of methane (from decaying organic matter) it can have a 25 times greater effect than the equivalent amount of CO2 from a car or the heating of a home. 

Part 3- The Zero Emissions Part of the Plan

As already discussed in the first 2 parts, the City of Vancouver's Zero Emissions Plan has a three pronged approach to get to zero emissions. District energy, a switch to electricity for heating and changing the sustainable building standard from LEED to a building envelope focused standard called Passive House.

In part 1 we covered how the LEED standard was responsible for a 30% emissions reduction since 2007, and in part 2 we covered how district energy was supposed to make up a good portion of the 70% the city is short for zero emissions. In part 2 we focused only on the technical and regulatory challenges with district energy but didn't cover the full lifecycle GHG impact of a biomass or other organic matter district energy system.

How Biomass Is Not Zero Emissions

The biggest flaw with the City of Vancouver's general idea of using biomass (wood waste or other) as a carbon neutral heating source (whether in a building boiler or a district energy system) is that it's not very carbon neutral.

The Challenge with Wood as Fuel Source

In a recent Oregon State University study,

"we found that if you harvest wood for energy, whether it be for fire prevention or simply for energy itself, the emissions associated with these activities are more than the savings that you get by substituting for fossil fuels."

While this may seem a little counter-intuitive it makes sense with the new science we know about how a forest sequesters and holds carbon. In general we now understand how it's not really the wood from the tree that holds and helps with carbon reduction but the overall health of the forest itself. Surprisingly most of the carbon in a forest is in the roots and soil, meaning the overall health of the forest is what holds the carbon in place. If we start to mess with that natural state we really mess with the amount of carbon the forest holds.

The other big part of the problem is that wood is not a very good energy source and the City of Vancouver just doesn't have enough to use for heating. First you have to send a diesel truck to get the wood (someday though these could be electric, but that's not always GHG neutral...see below), then you need to process it and then you need to dry it so it will burn. All in all you may be using more energy to do this than the energy that is in the wood itself.

How Our Electrical Supply is Not Zero Emissions

Electric in Vancouver has a GHG footprint of about 11 metric tonnes per GWh. For context natural is 180 tonnes per GWh. While our electricity is clean relative to natural gas BC Hydro (despite the name) is not a completely hydro electric based utility. It has natural gas plants within it's portfolio and will buy from other fossil fuel sourced electrical providers during peak electrical demand periods.

It's also worth noting that the 11 metric tonne number is not without controversy. While the BC Government consider large scale hydro electricity as carbon neutral there are many that think it may have a much larger impact. One such organization is the Center for Resource Solutions who administer the Green-e standard for carbon neutral energy.

Hydro Dam Reservoir GHG Sources

The biggest reason is that the reservoirs from large scale hydro can be a significant source of GHGs. While this is certainly a greater problem in a tropical environment, BC as a boreal rainforest environment isn't a different as we'd like to believe. There is also the environmental impact of flooding an entire river valley and eliminating the forests within them, the natural spawning of fish etc etc.

How Our Current Lowest Carbon District Utility is Not Zero Emissions

The City of Vancouver's Southeast False Creek (SEFC) Neighbourhood Energy Utility sits at the bottom of a very large hill where much of the sewage flows towards a treatment centre on the North Shore. A cleverly placed heat pump (one of the largest in the world) sits under the Cambie Street bridge very intelligently grabbing the waste heat and transferring it (not very intelligently) 3 blocks away to the Olympic Village. By the City's own estimates the heating centre is about 65 metric tonnes per GWh. While this is better than natural gas it's not a good as electricity in BC. Although it might be equal if we accounted for hydro dam reservoir emissions. By the City's own numbers 30% of the heating load from the SEFC Neighbourhood Energy Utility is from natural.

SEFC Energy Utility Schematic

The City hopes to add closer and further away residential developments to the utility. The biggest question for facilities more than 3 blocks away is whether the same metric tonne value per GWh actually makes sense. For example there are potential plans to connect develops close to 2 kilometers away near the BCIT Great Northern Way campus. That's a long way from the current source of heat.

Conclusions

The best sources of zero emissions energy, solar and wind technology are completely absent from the discussions within the City of Vancouver's Zero Emissions Plan. Other systems such as air source heat pumps are also not part of the discussion. An air source heat pump has a Coefficient of Performance (COP) of 2.8. COP is this amazing thing where you take 1 unit of  energy (in the case of air source heat pumps its electricity) and you get 2.8 units of heating out of it. If that electrical energy were from wind or solar we'd truly be able to have a conversation around a true net zero emissions plan.

Part 2: Problems with the City of Vancouver Zero Emissions Building Plan- 2 of 4

Neighbourhood Energy Utilities and Zero Emissions

District energy isn't a new concept. Providing energy to multiple buildings from a single source often makes a good deal of sense on a university campus, healthcare campus or other tight collections of buildings. It's also really useful when you have a diversity of buildings. If one set of buildings is rejecting heat and another is demanding heat, then you can meet demands with the shared infrastructure that a district system provides. 

The challenge then becomes when to apply district energy. Who can own it and what can they charge for heating? How efficient is the system? What's it's fuel source and what is it's full life cycle carbon footprint? How much does it really cost compared to other forms of heating?

Part 2- The District Energy Part of the Plan

In essence a district utility becomes a bit of a monopoly. The City of North Vancouver (Lonsdale Energy Corp) runs their own heating utility that operates off of natural gas on behalf of the City of North Vancouver . Dockside Green has a utility that runs on dry wood waste and the Vancouver Olympic Village has a system that draws heat from sewage with natural gas peaking and back up. 

The idea is to embed district energy into any new large rezoning. Pushing developers or other private entity to create a district heating system. While most systems will start off using natural gas, the idea is that systems could change over to lower carbon heating solutions like wood waste (more on that in Part 3). With a move away from natural gas for heating, the idea is that all heating in Vancouver will be carbon neutral (although the exact technical details are absent from the plan). 

The Cost

While cooling is becoming more and more in Vancouver, we're just going to focus on heating costs since this is what the City of Vancouver is focused on for district energy systems, since the idea is that heating is where the biggest carbon footprint comes from in buildings. 

In simple terms it costs 9 cents a kWh to heat with electricity in BC, 3 cents a kWh to heat with natural gas and about 13 to 20 cents a kWh for heat from a district energy system (depending on the system and how they bill). Much of the increased cost for a district utility is a result of the added infrastructure associated with a district system (the insulated piping, the pumping, the operations etc).

The biggest challenge with choosing any heating system is that fuel sources are always unpredictable. There do appear to be some constants with regards to fuel price for heating. 

If you look at the price of natural gas you see that the prices go up and down over time. They are at historic lows now but we all remember them being much higher.

Natural Gas Price Fluctuations

Electricity pricing on the other hand is something that almost always climbs pretty steadily. 

Electricity Cost Steadily Increases

A district energy system (based on it's fuel supply) is subject to the same price fluctuations but because of the greater infrastructure cost associated with district energy the costs are higher per kWh with a host of expensive fixed costs. Price transparency is particularly difficult so a direct comparison is hard as one Olympic Village resident complained

"The problem is that the consumption charges on my bill are dwarfed by fixed charges. 2/3 of the total bill is for flat fees that are charged regardless of what I use."

Getting Approval

The BC Utilities Commission (BCUC) has not been keen to approve most privately owned district energy systems. The most recent Chinatown system was denied, for a host of reasons by the BCUC. Chief among them is that it would give the private entity that would run it exclusive rights to supply heating to buildings limiting the choice for cheaper forms of heating (such as electrical or gas). The real question goes back to choice and when looking at the cost from above most people would likely chose to heat with natural gas. 

The BCUC is a little more likely to approve a district energy plant on a campus (since all buildings are owned by the same entity) or to a government municipality. The thinking on the government run system level is that governments will be more transparent on pricing and are more focused on provided heating as a need rather than at significant profit. However in the most recent case of the Chinatown denial, the BCUC felt that more competitive pricing options existed for heating and that it would not be in the public's best interest to approve a sole service provider. 

The Efficiency  

The efficiency of a typical condensing boiler is up in the 95% range. While a district energy system is often lower (although it can make up some of that inefficiency by moving free heat from some buildings to other buildings). Both the old Vancouver building standard LEED and the potential new standard Passive House (more on this problem in part 4) account for the lower efficiency of district energy systems in their rating. 

Green Buildings Should Generate Energy On Site

The LEED energy section accounts for district energy efficiency by making the baseline cost the same as the proposed building so that you don't get penalized for the inefficiency of the farther off heating source. City staff (as they push district energy) are currently letting energy modelers skirt this issue on code compliance models by not forcing them to be the same value. This allows a design that would not quality under LEED standards to pass at the city code level so as to ensure that district energy is not seen as a penalty to developers who currently also have to pursue LEED Gold on rezoning projects (although the two come into conflict regardless). 

Passive House accounts for the inefficiency of district systems by using source energy as their baseline for their energy intensity target. This means that you must also account for the line loss, pump energy, and all other factors associated with inefficiency of energy not produced on site. If the City were to move away from LEED (which is not recommended) to Passive House, the same allowance for district energy being used today would also be needed for Passive House buildings to meet their standard. 

Conclusions

The discussion of district energy systems isn't a simple one, although it was simplified for this conversation around the City's Zero Emissions Plan. In general though the World Business Council on Sustainable Development is calling for energy to be produced on site (ideally with renewables like solar or wind). In order to get the efficiency out a district energy system we would need to place buildings that reject heat near buildings that are demanding heat (something that zoning bylaws in Vancouver generally discourage since it likes to cluster residential together). At the same time there is a hesitance from regulatory bodies to allow for the ubiquity of district systems that the City would need to meet it's carbon neutrality in heating strategy. At the same time the price of heating and the actual feasibility of using district energy as carbon neutral energy is a big question. In Part 3 we will explore the carbon neutrality aspect in more detail. 

Part 1: Problems with the City of Vancouver Zero Emissions Building Plan- 1 of 4

The Baby Get's Thrown Out with the Bathwater

Vancouver endeavors to be the greenest city in the world, and the city is attempting to create a new (theoretically) stricter building policy towards that end. Vancouver recently introduced a new Zero Emissions Building Plan in a 62 page report to council which they hope will become a zero emissions building code. It’s objective is to reduce emissions from new buildings by 90% by 2025 (compared to 2007), and have zero emissions in all new buildings by 2030. We will examine this plan in a 4 part series. 

Part 1- Creating a new plan when the old one seemed to have been working

Part 2- The district energy part of the plan. 

Part 3- The zero emissions  part of the plan. 

Part 4- The Passive House part of the plan. 

Part 1- Creating a new plan when the old one seemed to have been working

According to their own data, from 2007 to 2015 the city reduced their energy usage in buildings (through use of building codes etc) by 30% in new buildings and by 20% overall. In simple math that means if the City kept their current strategy their new buildings emissions will have been reduced by 55%. That's 35% off their new target to be fair but any strategy that is giving you a 2.5% yearly reduction would be a strategy one would build upon rather than abandon. Yet that is what City staff are proposing within the new zero emissions plan. 

The Current Standard

Vancouver’s current sustainable building standard for new buildings (requiring rezoning) is LEED Gold and ASHRAE 90.1-2010 for everything else that isn't a single family home. The LEED Gold requirement requires 22% better than ASHRAE 90.1-2010 which would suggest that if the City simply applied the rezoning policy to non-rezoning projects they might be well on their way to making up their 35% shortfall with their current plan of a 90% reduction by 2025. 

Both the USGBC who administers LEED and their partners at ASHRAE are constantly improving energy code standards as they have a similar goal as the City of Vancouver to have zero emissions buildings. The CaGBC also recently released their Zero Carbon Building Framework. 

Energy Standards Improvements

LEED and ASHRAE have unquestionably been the prevalent choice in the industry thus far with many cities adopting 90.1 and LEED as their standard before the City of Vancouver. LEED has such wide adoption because it is a holistic approach, addressing most issues of sustainable building such as energy efficiency, water usage, materials, transportation and location. On the other hand, Passive House has an astigmatic approach to sustainability, focusing only on energy savings. However energy and carbon savings savings can come in more forms that just your building using energy of one form or another. In a recent article, Tristan Roberts points out that 

The energy content of the gasoline used by the typical office commuter each year is comparable to the energy used by his or her share of the building where he or she works.

Which means that having good bicycle infrastructure in a building can have an greater impact on carbon reduction in the city of Vancouver than many building energy efficiency strategies. 

ASHRAE 90.1 for those who don't know is a building standard that has been around since the 1970's. Our national energy code is modeled on ASHRAE 90.1 and the standard covers a very wide variety of building types from residential, healthcare to super energy consumptive data centers. 

With the new Zero Emissions Building Plan, city staff appear to be pushing for Passive House or other building envelope standard to replace LEED for the city’s building standard by 2018 while simultaneously pushing district energy (or neighbourhood utilities as they call it) in new and existing building areas. 

Preview of Parts 2,3 and 4

The two largest problems with the City of Vancouver plan is that the city is pushing district energy at various levels (less efficient that building level systems) while the cost of natural gas is at an historic low. The one problem makes it technically more difficult to reduce carbon at a city level while the other makes it financially more difficult.

1. District energy makes meeting LEED and Passive House standards more difficult. The main reason is that both rating systems account for the inefficiency of district energy systems (line loss, pumping energy, etc) as they are both focused on more than just building efficiency. LEED accounts for it by making the baseline building cost the same as the proposed new building. City staff currently let people skirt this issue on code compliance models by not forcing them be the same value, thus allowing a design that would not qualify under LEED standards to pass at the city level so as to ensure that district energy is not seen as a penalty to developers who currently also have to pursue LEED Gold. Passive House accounts for the inefficiency of district systems by using source energy as their baseline for their energy intensity target. This means that you must also account for line loss, pump energy, and all the other factors associated with energy that is not produced on site. Should the city move away from LEED (not recommended) to Passive House the same allowance for district energy being used today would also be needed for Passive House buildings to meet their standard.
2. A wood based district energy systems would have to also ignore the embodied carbon associated with the diesel trucks, diesel power chain saws and other gasoline systems that would be used to get the wood to the neighbourhood utilities. Please also note that wood burning systems (because wood doesn’t burn as cleanly as gas) require frequent flush outs (i.e. running gas through the system to burn off wood waste) in order to continue running effectively. Combine this with the current price difference between electricity and gas and it will make it financially difficult to convince stratas and public entities to make the fuel switch that would create the quickest carbon reductions in buildings. The current price of residential electricity is currently around 9 cents kWh while the price of natural gas is only 3 cents a kWh. Should the city enforce a code which is merely GHG based without accounting for other factors, developers will simply switch from more efficient gas heating to less efficient electric heating while also passing off the additional operating costs to home buyers.

Please tune in next week for more detailed discussion of district energy systems as they apply to GHG reduction and the City of Vancouver's Zero Emissions Plan. 

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