New study shows significant energy cost savings to owners in Tridel LEED certified condo building

LEED certified tower at Tridel development Parc Nuvo in Etobicoke used half as much natural gas as its non-LEED neighbour

By Jamie James

It has been a long time coming, but we can finally demonstrate the savings that accrue to condominium owners living in certified green, energy efficient residential highrises. 

TowerLabs@MaRS, a non-profit green building research and development organization, recently completed a study for the Ontario Power Authority focusing on two new condo towers constructed in Etobicoke by Tridel. The buildings offer an excellent case study in building energy use, as they are similar in scale and were built within two years of each other on the same site. The main difference is that the newer building was certified to a LEED-Silver standard by the Canada Green Building Council and was outfitted with thermal sub-meters in each dwelling unit to enable owners to manage their own energy costs.  

A comparison of the gas and electricity bills over the course of a two-year period reveals a stark contrast in energy performance. The LEED certified tower recorded a reduction in energy intensity—that is, energy use per square foot of floor area—of 41% in comparison to its neighbor. While electricity costs were modestly lower in the LEED building, the major surprise was in the amount of natural gas saved: half as much in the LEED building. From a climate change perspective, this is significant, as every cubic meter of natural gas saved avoids C02 emissions that affect the natural balance of our atmosphere. 

Exceptional natural gas savings is also an important harbinger of future savings. Natural gas prices have been at historic lows, but the commodity is subject to considerable volatility over time. Since the LEED tower uses so much less natural gas, we can anticipate that this building will be better insulated against future inflation than its neighbor.

Translating the energy savings into costs savings offers especially good news to the LEED building residents. They are spending on average $124,000 less than their neighbors. Since their building is actually a little bit larger, the savings understate the level of efficiency designed into the building. 

There are two important lessons to draw from this study. The first is that building energy modelers can predict with some accuracy the energy savings that will result from energy efficient designs. The LEED building actually used $20,000 less energy than anticipated by the model. This should give condo developers confidence that energy models are useful tools when it comes to estimating the energy component of the first year operating budgets. More importantly, mortgage lenders should take them seriously when calculating the cash flows of a prospective borrower who wants to buy into a green community.

The second take home message from the study is that the Green Condo Loan, financed by the Toronto Atmospheric Fund and assigned to the Condominium Corporation by the developer in order to pay for some of the incremental construction costs, was a worthwhile investment. The net savings to the condominium owners after paying back the principal and interest on the loan in a 12-month period was $74,000 in comparison to the non-LEED building, after normalizing costs based on energy intensity ($37,000 compared to the estimated energy savings in the energy model).

Sustainability cannot be accomplished with good intentions alone.  We need to accomplish real empirical reductions in energy use if we want to tackle global challenges like climate change and protect ourselves from the rising costs of resource scarcity. Tridel’s new green condo towers are leading the way, and leaving cash in the pockets of their customers at the same time. Hopefully, mortgage lenders will take note.  

Jamie James is Tridel's Sustainability Advisor and a founder of TowerLabs, a non-profit green building technology research and development organization based at the MaRS Discovery District.