Build Better: Exterior Walls

When building a new home or adding an addition, the quality of construction depends on how the wall is built. Most architects or homeowners overlook the walls. 

This is a major problem. 

Having worked on homes for celebrities, I can tell you that the secret to elevating a home from a n overpriced McMansion build to a world-class piece of architecture lies in the walls. Investing in a better wall assembly is the single most impactful way to improve a home's feel, quietness, and longevity.

Building Better Walls

1. Prevent energy leaks: Depending on an HVAC system to make up for inefficient wall structure is costly. 
2. Quiet and solid: Not hearing traffic or inclement weather outside conveys a sense of safety and reduced stress

Bad Wall Problems

Having a home with cold walls is more than just a comfort issue, they are a health liability. When the interior surface of a wall drops in temperature, it triggers a chain reaction:

1. Energy Drain: The HVAC system will work overtime to combat the radiant cold surfaces.
2. Condensation: Warm interior air hits the cold surface, turning into liquid water inside the wall.
3. Mold Growth: Hidden moisture leads to rot and respiratory health issues.

Bad Wall Anatomy

The top image shows what is typically being built no matter whether the home is going to be sold for multimillion dollars or is for an affordable cost-per-square-foot single family home. 

• Insulation Failure: The most common walls being built in Colorado depend on pink batt insulation. The pillowy pink batts often slump or settle over time, leaving massive uninsulated gaps.
• Air Infiltration: Unsealed penetrations for things like plumbing and electrical are holes in the wall. They suck cold air directly into the home.
• Thermal Bridging: What most architects or builders miss. Metal and less so wood elements running from exterior to interior act as a highway for the cold, bypassing insulation entirely.
• Historic Homes: Solid masonry was designed for thermal mass, but in today’s extreme cold snaps, those walls simply freeze through.

Make Bad Walls Better

If you are having issues with your home feeling cold, walk the exterior with a can of spray foam and a high-quality sealant. Seal every gap, including around where pipes or wires enter the home.

For large gaps, I recommend using GE Spray Foam. For smaller gaps, I recommend a Urethanized Elastomeric Sealant like SherMax. It’s affordable, has a lifetime warranty, and offers the flexibility needed for shifting temperatures.

The real solution to poor exterior walls is building a home with quality wall assemblies to begin with. Over the life of the home, having a quality envelope will pay back itself in dividends.