The Hidden Cost of Energy Waste in Rental Buildings

In a market defined by rising utility costs and normalized rents, operational efficiency is no longer a technical initiative. It is a portfolio imperative.

Across Canada, much of the purpose-built rental housing stock was constructed in the 1960s and 1970s. At the time, energy efficiency was not a design priority. Fuel was inexpensive, technology was limited, and mechanical systems were intentionally oversized to eliminate risk and liability.

Decades later, those same design decisions are still shaping operating costs.

Most multi-unit residential buildings today fall into one of three broad mechanical profiles:

1. Hydronic baseboard heating with no central cooling

2. Electric baseboard heating with no central cooling

3. Fan coil or heat pump systems introduced in later generations of construction

While each configuration differs, they share a common issue. They were designed conservatively, operated passively, and rarely re-engineered to reflect today’s energy realities.

The result is persistent, always-on waste that quietly erodes operating margins year-round.

The hydronic baseboard challenge

In older hydronic buildings, central boilers circulate hot water through vertical risers and perimeter baseboards. These systems were designed with generous safety factors. Pumps were oversized. Boilers were oversized. Flow rates were rarely optimized.

Granular control was limited or non-existent.

Upper floors often overheat due to stack effect and uneven distribution. Tenants compensate by opening windows during winter months. In many buildings, it is common to see windows partially open while the heating system runs at full output.

From an engineering perspective, this is simple heat rejection to the outdoors.

From a financial perspective, it is utility dollars escaping every hour.

Because circulation loops typically run continuously throughout the heating season, energy use remains high even during mild shoulder months when full output is unnecessary. Without proper reset controls, boilers operate hotter than required, increasing natural gas consumption and cycling losses.

Owners often replace aging boilers with newer units but maintain the same piping configuration, pump sizing, and distribution logic. The equipment becomes more efficient on paper, yet the systemic inefficiencies remain intact.

Operating costs do not materially decline.

The electric baseboard problem

Electric resistance heating was once inexpensive to operate. That is no longer the case.

Electric baseboard systems convert electricity directly into heat at nearly one-to-one efficiency. However, electricity prices have changed dramatically over the past decades. What was once a low-cost heating solution has become one of the most expensive forms of space heating in today’s utility landscape.

These buildings typically lack central control. Each suite operates independently, and common area loads are rarely optimized. With limited central oversight, energy intensity remains high, and consumption patterns are difficult to influence without a structured optimization strategy.

As electricity costs rise and volatility increases, these portfolios face mounting operating pressure.

The make-up air reality

Perhaps the most overlooked energy driver in rental buildings is the make-up air unit.

Make-up air systems often operate using 100 percent outdoor air to replace exhaust from corridors, bathrooms, and kitchens. In many multi-residential buildings, ventilation and make-up air heating account for up to 30 percent of total natural gas consumption.

In older buildings, these units were frequently oversized using generous safety factors. Airflows were set high to ensure compliance and eliminate complaints.

Once commissioned, they were rarely recalibrated.

Oversized ventilation equals oversized heating load.

Every cubic foot of outdoor air brought into the building during winter must be heated to room temperature. If airflow is 20 to 30 percent higher than necessary, operating costs increase proportionally every single month.

Because these systems run continuously, the financial impact compounds.

Evolution without correction

As building design evolved, fan coil systems and heat pump applications were introduced. Boilers became more efficient. Controls became more advanced.

Yet many of the original deficiencies persisted.

Plants remained oversized. Distribution imbalances were left unresolved. Scheduling strategies were rarely revisited. Control sequences were not optimized for actual occupancy or weather conditions.

Operators inherited mechanical infrastructure designed decades ago and continued to replace equipment like-for-like. Capital expenditures occurred, but systemic waste remained embedded in the design.

As utility costs rise and rent growth normalizes, this inefficiency becomes a financial liability.

Measuring the cost of always-on waste

Always-on waste does not show up as a single line item. It appears as elevated energy use intensity compared to similar buildings. It appears as high shoulder season consumption. It appears as boilers running harder than weather conditions justify.

In a typical 200-unit hydronic building, even a 10 percent reduction in heating load through optimization can translate into tens of thousands of dollars annually in natural gas savings. In larger portfolios, the cumulative impact across multiple sites becomes significant.

The same principle applies to make-up air optimization and pump control strategies.

When ventilation loads account for up to 30 percent of gas consumption, correcting airflow oversizing and implementing proper reset logic produces measurable financial impact without replacing major equipment.

This is not theoretical efficiency. It is operational correction.

The urgency to act

The economics of rental housing are shifting. Operating costs are rising. Utility volatility is increasing. Regulatory scrutiny is expanding. Rent growth is stabilizing.

The margin for mechanical inefficiency is shrinking.

Every heating season that passes without optimization locks in avoidable expense. Every equipment replacement that ignores systemic design issues compounds the problem.

Owners who take inventory of their mechanical performance now can reduce both operating expenditure and future capital exposure.

Optimization does not require wholesale replacement. It requires measurement, recalibration, and intelligent sequencing.

It requires asking a simple question.

Is your building operating the way it was intended, or simply the way it has always been?

The path forward

For multi-residential portfolios, the most immediate and controllable opportunity lies in:

• Hydronic loop balancing and temperature reset strategies

• Boiler staging optimization• Pump control recalibration

• Make-up air airflow optimization

• Ventilation scheduling refinement

• Eliminating simultaneous heating losses

These measures focus on correcting waste embedded in legacy design rather than replacing assets prematurely.

In a market where controllable cost reduction is increasingly valuable, eliminating always-on waste is not a technical exercise. It is a portfolio strategy.

The buildings constructed in the 1960s and 1970s were not designed for today’s energy environment. But they can be operated intelligently within it.

The time to act is now, before another heating season passes and another cycle of avoidable cost is absorbed into operating budgets.

About NERVA Energy

NERVA Energy is a distinguished multidisciplinary engineering firm, renowned for its cutting-edge energy performance solutions. With an elite team composed of seasoned energy engineers, M&E engineers, and seasoned in-house mechanical technicians, NERVA is steadfast in its commitment to delivering turn-key solutions. These solutions not only amplify building energy efficiency but are also backed by a steadfast financial performance guarantee.

To learn more about the company and our services, visit:

 www.nervaenergy.com