Buildings are energy hogs. Nearly half (49.6%) of the total energy consumption of commercial and industrial buildings in Canada is used for heating and cooling spaces, which contributes to 42.9 per cent of the sectors’ greenhouse gas (GHG) emissions. Thus it is important that measures are taken to reduce the energy consumption of buildings, with a special focus on heating and cooling loads.
This is not news, but it has presented a challenge for building designers over the last few years: how can a building be designed to maintain its exterior beauty while significantly reducing its energy consumption?
The high-rise buildings that dominate most downtown cores across Canada may be pleasing to the eye, but what really counts is hidden behind the walls. Not only do fibre glass, rock and slag wool (i.e. mineral fibre), insulation wall designs provide peace of mind with effective moisture and fire protection, but they also have much to offer by reducing a building’s energy consumption. For example, they can offer savings on utility bills [Savings vary. Find out why in the seller’s fact sheet on R-Values. Higher R-Values mean greater insulating power.], which can then be invested in business growth opportunities or improved competitiveness, such as reduced prices for consumers or higher profits for shareholders. Highly insulated and well-ventilated buildings can also provide its occupants improved indoor air quality, which could have an impact on their health, well-being, and overall productivity.
The market for energy efficient buildings already exists – and it is expected to grow. Energy efficiency code requirements are becoming more stringent, and energy efficiency labels on buildings are becoming more recognizable. Canada has adopted a benchmarking system that is making it easier for building owners to track and assess their energy consumption, and to compare their performance with other buildings of a similar type. It is important, then, that buildings are not only designed to look aesthetically beautiful, but also with energy efficiency in mind – and that means taking mineral fibre insulation into consideration when designing the building envelope.
Energy efficiency code requirements
The commercial building sector is changing as more jurisdictions across Canada adopt the 2011 National Energy Codes for Buildings (NECB) or their own energy efficiency codes (e.g.., Supplementary Bulletin 10 (SB-10) of the Ontario Building Code). While the 1997 Model National Energy Code for Buildings (MNECB) was the first to introduce energy efficiency standards for commercial, institutional, industrial, and large residential buildings, it is the 2011 NECB that has been effective at setting a precedent for more stringent minimum energy requirements in much of the country. This has put Canada in the running with other countries that are leading the way in energy efficient building construction.
Taking a holistic approach to constructing energy efficient buildings, the NECB allows designers to take either prescriptive, trade-off, or performance paths. In other words, there is some flexibility in design, as long as the building does not consume more energy than it would have otherwise. A building designed with more windows, then, would be required to compensate for its higher ability to transmit heat (known as the heat transfer coefficient, or U value) by increasing the level of insulation, for instance, in the remaining parts of the building envelope.
The national energy codes are typically revised every five years, and the next version of the NECB is expected in December 2015, but has minimal changes to energy efficiency. The plan for the next version to be released in 2020 is to improve energy efficiency by 20 per cent. Currently, there are a number of proposals that are being discussed that would affect the building envelope and required insulation levels, including lowering the maximum U-values for each climate zone, limiting trade-downs in the performance and prescriptive paths, and reducing the amount of sky-lights allowed.
As the provinces and territories adopt the revised versions of the NECB, buildings that were once high performers might then lag behind new buildings. Therefore, designing buildings with insulation levels beyond what is required by code can offer building owners added value in the long run. Voluntary programs, such as building certification and benchmarking, can also provide designers the motivation to do just this, which in turn increases the supply of energy efficient buildings on the market.
The market for energy efficient buildings
Building certification has done a lot for raising awareness and opening up the demand for “green” buildings that are said to be more energy efficient than those built to code. Most people could probably identify the ENERGY STAR label or recognize the LEED (Leadership in Energy and Environmental Design) plaque on a building. Some people pay a premium to occupy spaces in green-certified buildings with the understanding that they will save money on their energy bills and that they can advertise they are doing their part to help the environment. Some businesses also pay the premium for the added benefit that they will be given a competitive advantage during the recruitment process, attracting people who want to work in healthier and environmentally responsible offices.
However, spotting an energy efficiency label on a high-rise building made with large windows areas raise some questions, such as: how much energy will the building conserve? Is it actually more energy efficient than the uncertified ones?
For such a building to merit a strong energy efficiency label, the energy efficiency of the interior must compensate for the poor energy efficiency of the building envelope. But what if the interior mechanicals (heating, ventilating, and air conditioning – or HVAC – and hot water system) are not well maintained, or a subsequent tenant replaces parts of the building interior? It is suggested that the most durable, sustainable contribution to a building’s energy efficiency is its well-insulated envelope – not its interior features.
There are a number of certification programs recognised in Canada, including Canadian Green Building Council (CaGBC)’s LEED and Building Owners and Managers Association of Canada (BOMA Canada)’s BOMA BESt® (Building Environmental Standards). BOMA BESt® certifies existing commercial buildings after assessing the environmental performance and management, not only accounting for its energy efficient design, but also its performance over time. Applicants are required to submit utility bills, so certification is granted to buildings that can demonstrate energy savings. Not only that, but through recertification every three years, the label maintains the building’s status as energy efficient.
On the other hand, although the LEED standard is widely recognized and widely adopted by governments, it has been criticized for certifying buildings that do not demonstrate higher levels of energy efficiency when compared to those built to code. This could be in part due to the certification process and to the application’s rating system. Firstly, applicants do not need to recertify after a specified amount of time. Secondly, the focus of the rating system’s energy section includes sustainable materials and resourcefulness, the indoor environmental quality, and the overall energy performance.
However a large drawback of the LEED standard is the lack of focus on the building envelope. Despite containing highly efficient mechanics or sustainable materials, a building constructed without regard to its building envelope could result in the consumption – and waste – of a lot of energy.
That said, developers of the LEED program recognized that certified buildings require maintenance to continue to function efficiently. For this reason, the LEED system also includes a benchmarking tool that allows the buildings’ owners and managers to monitor their energy consumption, and compare its current levels to what was achieved at the time of certification.
On the path to a standard benchmarking system
Many people want to keep up with the Joneses. Thanks to some benchmarking tools, people can see how their buildings’ energy consumption compares to the family who has everything, and these tools could result in a larger market for energy efficient buildings.
Natural Resources Canada (NRCan) is currently in the process of adopting the U.S. Environmental Protection Agency (EPA)’s ENERGY STAR Portfolio Manager. The benchmarking tool has been successful in the U.S.: it is the leading tool, with 40 per cent of commercial building space using it, including more than half of the Fortune 100® companies, half of the largest healthcare organizations, education facilities, and municipalities. The success story is expected to continue in Canada, as thousands of commercial buildings have already been registered and green building certification programs, such as BOMA BESt® and LEED, align their requirements to it.
Photo: Thinkstock/NAIMA Canada
In Canada, it is being adopted as the platform for the nationwide benchmarking program for existing buildings. Since its inception in July 2013, more and more building types are able to register. To date, K-12 schools, commercial office buildings, hospitals, supermarkets or food stores, and now medical offices can register, and more will be added.
Municipalities have used the tool to motivate building owners and managers to benchmark and retrofit their buildings. For example, the Great Toronto Civic Action Alliance’s Race to Reduce aims to reduce the energy consumption of registered office buildings by 10 per cent, and the City of Richmond in British Columbia has the EnergySave program that has set a goal to reduce GHG emissions by 33 per cent by 2020.[x]
As an alternative compliance path, the NECB is currently evaluating CSA Group’s C873 Series-14, Building Energy Estimation Methodology (BEEM). Adapted to the Canadian market, it provides simplified building energy calculations with results similar to those modelled in CanQuest – Canada’s building energy simulation software that can be used to demonstrate performance path compliance with the NECB – and has a proven track record of more than 8 years in Germany. If the proposal for its adoption into the NECB is accepted, it will allow existing buildings to benchmark their energy performance to new builds. This could be the motivation owners and managers of existing buildings need to invest more in energy efficiency.
What makes benchmarking different to other “green” initiatives is that it shows people how their buildings measure up, and where their strengths and weaknesses are when it comes to energy efficiency. The report shows people whether their buildings’ energy performance is weak, and if so, where they can improve and which measurements would show them the biggest bang for their buck. Perhaps their mechanicals are poorly functioning, their technology is outdated, or the building is poorly insulated. Benchmarking would show that a building with highly efficient mechanicals but which has poor insulation, is still a leaky energy hog.
Conclusion
Canadian cityscapes can be identified because of the interesting and beautiful shapes of their commercial buildings. There is a push today to not only design aesthetically pleasing buildings, but to also make them energy efficient. Though energy efficiency codes push for tighter building envelopes and energy labelling helps grow the market for “greener” buildings, it is energy benchmarking that is changing the game. It shows building designers, owners, and managers which measures will have the largest impact on reducing energy consumption, and they can see whether their buildings are energy efficient or not. Benchmarking makes the invisible visible, and it shows preference for energy efficient designs rather than purely aesthetic ones.
