Does the Color of Your Home Matter for a HERS Rating in MA?

Homeowners often ask an interesting question during the design phase:

“Will the color of my house affect my HERS rating—and are there any energy benefits to choosing certain colors?”

The answer is yes, exterior color does influence a HERS model. But the impact is usually smaller than most people expect, and in a cold climate like Massachusetts, the direction of that impact may surprise you.

How Exterior Color Shows Up in a HERS Model

HERS software assigns a value called solar absorptance to exterior surfaces such as siding and roofing.

• Darker colors absorb more solar energy

• Lighter colors reflect more solar energy

That absorbed energy slightly warms the building enclosure, which can reduce heating demand in winter and increase cooling demand in summer. The model accounts for both effects.

But Massachusetts is firmly a heating-dominated climate (Zone 5A). Because we spend far more energy heating homes than cooling them, the math often works in favor of darker exteriors.

Why Darker Colors Can Actually Help in MA

It sounds counterintuitive, but in New England:

• Winter solar gain is generally beneficial

• Additional heat absorbed by darker siding or roofing can slightly reduce heating load

• The cooling penalty in summer is real—but typically smaller than the winter benefit

From a HERS perspective, this means darker colors are often a mild net positive, not a penalty, for overall energy performance in Massachusetts homes.

The Summer Tradeoff Is Real—But Usually Modest

There is no free lunch. Darker surfaces can lead to:

• Higher exterior surface temperatures

• Slightly higher cooling energy use

• More reliance on shading and good window performance

However, our cooling season is short, and modern heat pumps and mini-splits are very efficient at handling those loads. In most projects we model, the annual heating benefit outweighs the summer downside.

Let’s Keep It in Perspective

Here’s the key point many homeowners miss:

Exterior color is a fine-tuning knob, not the steering wheel of a HERS score.

Typical impact we see in real projects:

• 0–1 HERS point for most homes

• Occasionally 2 points in very exposed, unshaded designs

• Rarely more than that

Compare that to factors like:

• Heating system selection: 8–15+ points

• Window U-factor and SHGC: 2–5 points

• Airtightness: 3–10 points

• Duct strategy: 2–6 points

Color matters—but it’s nowhere near as powerful as envelope and equipment decisions.

Roof Color vs. Siding Color

Not all surfaces are equal.

• Roof color generally has more impact than siding because of direct sun exposure and the large horizontal surface area.

• Walls experience more shading from overhangs, trees, and neighboring buildings, which reduces the influence of siding tone.

• Orientation matters—south-facing surfaces typically have the greatest annual impact in Massachusetts due to winter solar gain, while west and east exposures mainly influence summer cooling loads.

So if energy performance is part of your decision, roof tone usually moves the needle more than wall color—and southern exposure plays the biggest role in annual results.

When Color Matters Most

Exterior color becomes more relevant when a home has:

• Large, unshaded roof areas

• Significant southern exposure

• Minimal overhangs or exterior shading

• Borderline HERS targets (like chasing 45 or 42)

• Limited cooling capacity

In those situations we’ll pay closer attention to absorptance values in the model.

Practical Guidance for Massachusetts Homeowners

1. Choose colors you love first.
   Don’t design your home around paint just to chase a HERS point.

2. Focus on the big drivers.
   Windows, HVAC equipment, airtightness, and insulation will always matter more.

3. If you’re on the edge of a target score, color can be a helpful nudge—but it’s not a rescue strategy.

4. Roof tone has more influence than siding tone.

5. Southern orientation drives annual performance; east and west mainly affect summer comfort.

The Bottom Line

Yes—exterior color does affect a HERS rating.
But in Massachusetts, darker homes often align surprisingly well with our heating-dominated climate. The effect is real, just modest.

Think of color as the last 2% of the equation—not the foundation of energy performance.

If you’re planning a project and want to understand how design choices like windows, equipment, airtightness, and even exterior color interact in your specific home, we’re happy to help model the options.

Reach out to Spectrum Energy to review your plans before decisions get locked in.