What You Should Know About the House As A System Approach

What Are The Components When Applying the House as a System Concept?

A systems approach to housing does not merely look at the building alone. Instead, it considers four main components: 

• The building envelope itself,
• its mechanical systems and inner workings,
• the environment, and 
• the home's occupants. 

How Does the Building Envelope Contribute to the House as a System?

The building envelope consists of the roof, walls, floors, windows, doors, insulation, and foundation. It provides a significant barrier that protects the mechanical systems and occupants. It is generally the first component considered because an effective building envelope allows for better (and often cheaper) mechanical systems and can increase their efficiency. 

How Do Mechanical Systems Contribute to the House as a System?

Mechanical systems consist of heating, ventilation, air conditioning, plumbing, and electrical systems. These systems regulate the indoor temperature, overall air movement, and indoor moisture levels. Heating and cooling systems should be appropriately sized for the home, and ventilation should be sufficient to protect the building and systems from moisture issues. 

How Does the Environment Contribute to the House as a System?

The environment includes the impact of conditions beyond the house, such as the house's orientation to the sun and the region's general climate. Homeowners can rarely change this component after home construction is complete, but they can influence it. For example, planting trees (increasing shade) or removing trees (increasing sun exposure) can help regulate the home's temperature without modifying the house itself. 

How Do Building Occupants Contribute to the House as a System?

Occupants include both the number of occupants in the home as well as their behaviors and habits that impact the home. These can include activities that increase moisture (e.g., bath/shower frequency and length) and impact temperature (e.g., preferred climate, leaving windows open, and choice in lighting). Homeowners and industry professionals can often overlook occupant behavior, yet, it is a significant energy consumption indicator, according to multiple recent studies.

What Are Some Examples of a House as a System Approach? 

Air Sealing

Creating a tight building envelope is a significant step in improving your home's energy efficiency. You will lose less heat through the building envelope by sealing air leaks in places like your attic and around windows. To seal air leaks with a HAAS approach, you must consider ventilation. If there is a mismatch between the building envelope and ventilation systems, moisture could accumulate inside the home. This moisture can cause mold growth, condensation on windows, and insufficient air circulation.

Insulation

We all know the importance of insulation to keep a home warm in the winter and cool in the summer. Rather than merely installing insulation, a HAAS approach would look at sealing the entire building envelope to optimize the insulation's performance. This approach will prevent moisture from entering the home and damaging the insulation.

Heating Systems

An ideal heating system runs efficiently and creates a comfortable indoor environment for its occupants. However, a HAAS approach would first look at sealing the building envelope. This sealing will ensure that the specified heating system will not be oversized and thus more expensive to operate. An insulated attic or other thermal envelope failures could make the heating (and cooling) systems work harder.

Is the House as a System Approach for New Construction Only? 

No, it is not! You can take a HAAS approach for well-planned home renovations to ensure the long-term success of renovation projects. The most important thing to remember is that when you retrofit one part of the home, the whole house system can be impacted.

What are the Primary Considerations When Retrofitting with the House as a System Approach?

There are three primary considerations when retrofitting a home with a HAAS approach: asbestos, carbon monoxide and combustion spillage, and mold. An ideal home retrofit balances the need to address existing issues and design to mitigate future problems.

What Is the Importance of a House as a System Building Approach?

Whether renovating or building a new home, it is essential to think of the House as a System (HAAS). The HAAS approach encourages homeowners to consider the intended or unintended consequences of building design, including energy performance, air quality, and moisture levels. This approach views the home as a series of interdependent components; every component has the potential to interact with any other.