Building Science Basics

As building codes become more rigorous and enclosure technologies advance, today’s homes and buildings must meet significantly higher performance standards. These include:

  • Higher levels of air-tightness
  • Greater insulation requirements
  • Continuous insulation systems
  • Integrated air and vapour barriers
  • High-performance windows
  • Increased electrical loads and load sharing

These features don’t operate independently—they interact as part of an integrated system. Without a solid understanding of how they work together, it’s easy to run into unintended consequences such as moisture problems, comfort issues, inefficiencies, or premature wear of building components.

How these features interact and work together – or against each other – are the fundamental building blocks of building science. Energy Advisors are trained in the fundamentals of building science, and can offer insight into the expected performance of a home and provide guidance to ensure your final result is a comfortable, healthy, safe and durable space for everyone.

Photo credit Alison Conroy, CACEA

What Is Building Science?

Building science is the study of how heat, air, moisture, and energy move through buildings. It helps us design, build, and maintain homes and structures that are:

  • Safer
  • Healthier
  • More durable
  • More energy-efficient
  • Environmentally responsible

With this knowledge, professionals can make informed decisions, avoid costly mistakes, and deliver higher-performing buildings.

Here’s Why Building Science Matters—In Simple Terms:

1. Protects Health and Comfort

Poor design can lead to mold, drafts, poor indoor air quality, and uncomfortable indoor temperatures.

  • Building science ensures homes stay dry, warm (or cool) when you want it, and properly ventilated—so people remain healthy and comfortable.
2. Reduces Energy Costs

Heating and cooling are major household expenses.

  • Building science shows how to insulate better, seal leaks, and ventilate efficiently—cutting energy use and saving money.
3. Prevents Damage

Moisture is one of the greatest threats to buildings.

  • Understanding how moisture behaves (rain, condensation, air leaks) helps prevent potential mold, rot,  structural damage and improve indoor air quality.
4. Supports Sustainability and Climate Action

Buildings contribute significantly to greenhouse gas emissions.

  • Building science helps create energy-efficient homes that lower carbon footprints and last longer.
5. Leads to Smarter Construction and Renovations

Builders and renovators need to make informed choices—about materials, insulation, mechanical systems, and ventilation.

  • Building science guides these decisions, helps ensure compliance with modern codes and standards, and that the right materials or equipment are used in the right place.
6. Promotes the “House-as-a-System” Approach

All parts of a home—walls, windows, HVAC, insulation—are interconnected.

  • Building science ensures changes in one area (like improving air-tightness) don’t create problems elsewhere (like trapped moisture or poor ventilation).

In short, whether you’re doing a small upgrade to your home or you’re a diligent new home builder, EAs can provide the building science guidance which is critical to creating homes that perform better—for people, the environment, and the future.

What is “House-as-a-System”?

Think of your house like a human body. All the parts—like the walls, roof, windows, heating system, and even the people living in it—work together as one big system. If you make a change in one area, it can affect everything else.

Key Principles:

  1. Everything is Connected
    When you change one thing in your home—like adding insulation or replacing windows—it affects air movement, moisture, and even how your heating or cooling system works. Just like how fixing one part of your body can affect the rest. A change in one part of the “system” can significantly have an impact on health, safety, comfort, energy efficiency, and durability.
  2. Air Flow Matters
    Air leaks and drafts don’t just make you uncomfortable—they can carry moisture and cause mold or damage. Proper air sealing helps control where air comes in and out of the house.
  3. Moisture Needs Control
    Moisture from cooking, showers, or even breathing needs somewhere to go. Without good ventilation, it can build up and lead to mold or rot.
  4. Comfort and Efficiency Go Hand-in-Hand
    A well-designed home system keeps temperatures consistent, uses energy wisely, and saves money on your utility bills.
  5. Health and Safety Are a Priority
    A healthy home has good air quality, proper ventilation, and no backdrafting of dangerous gases from appliances like furnaces or water heaters.

In short, a house isn’t just a bunch of separate parts—it’s a living system. Smart upgrades consider how those parts interact, so you improve comfort, energy efficiency, and durability all at once.