Saving money on energy is the primary reason for improving the performance of new and existing buildings. There may also be benefits in the long term that are harder to quantify.

When it comes to energy performance, energy audits and advising clients on strategies for energy efficiency, it is VERY important to remember these points:

• Controlling the behaviour of heat, air and moisture in a building is Job #1 for a building scientist. It is a complex job.
• There is ALWAYS a chance that errors will happen.
• Optimum performance is based on an ideal scenario where everything works perfectly. Nothing is ever perfect.
• The longer a building is standing, the more likely it will deteriorate. Energy efficiency may age poorly in buildings.
• There is potential for savings but no guaranteed savings. This is a volatile time in our history and energy systems are rapidly changing. Count on those changes affecting how a building performs in the future.

THE OPTIMUM PERFORMANCE

To achieve this goal, there are FIVE main strategies for new construction and retrofits:

1. Increased thermal insulation all around the building, based on location and heat loss calculations.
2. High quality windows and doors.
3. Strict airtightness below 1 air change per hour (ACH).
4. Elimination of thermal bridges.
5. Mechanical ventilation with heat recovery.

A well designed and well constructed building that uses these strategies may create an indoor environment that can be truly climate controlled with the highest efficiency possible.

WHERE DO THE LONG TERM SAVINGS COME FROM?

Operational savings:

If a building envelope minimizes energy losses through leaks and conduction, it may create a situation where mechanical systems don't have to work hard to control the indoor climate. In some cases, it may even be possible to use smaller appliances for heating, cooling and ventilation, effectively downsizing the systems to fulfill the comfort needs for building occupants.

This means that the capital expenditure on mechanicals could be reduced, as well as the expense for maintenance or replacement of systems that are worn out from high use.

Materials and Maintenance savings:

From a structural vantage point, an airtight building envelope is less likely to see warm, moisture laden air carried into built assemblies. Eliminating water accumulation in wall, floor and roof assemblies could prevent mold and rot throughout the life of the building, giving materials a longer period of durability and integrity.

The longer a building material lasts, the more we can amortize the initial expense of those materials over many years. Maintaining the integrity of materials means that we may not have to replace those materials in the future, instead treating them only with regular maintenance to extend their useful life.

Comfort and Health savings:

While it may be a little more difficult to calculate a dollar savings, we must consider the comfort and health of building occupants as long-term benefits for high performance.

A building that is consistently at a temperature and relative humidity that is comfortable to humans is going to provide increased well-being for occupants. Coupled with a constant flow of fresh air and properly vented exhaust air, the quality of the indoor environment may remain high year round.

What this could translate to is a more comfortable, healthier and happier person, who is less likely to require medical attention for respiratory issues and who may be less stressed over longer periods of time. Sleeping may be better, allergens in the air may be decreased and odours may be non-existent.

If we could improve the general health of our communities through improvements to our built environment, we may be able to decrease the costs of public health services for those communities. This is especially true in regions where there are vulnerable populations such as seniors, disabled and low-income tenants in public housing.