When Montana homeowners think about adding solar, they usually start with utility bills. That’s understandable.

But before we talk about kilowatts, tax credits, or resale value, we need to talk about something often overlooked: The roof.

Start With the Right Questions‍

How old is the roof?

Most asphalt shingle roofs are built to last 20–30 years. Metal can last longer. But no roofing system lasts forever — especially in Western Montana, where snow loads, ice dams, wind events, and UV exposure are constantly impacting the lifespan of exterior building systems.

Solar panels are designed to perform for decades; typically rated for 20-30 years. But, if you install them on a roof that has 5–10 years of life left, you’ve created a future expense: The system will have to be removed and reinstalled when the roof is replaced.

That additional cost is not catastrophic — but it’s not free.

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Before going solar, the roof should be evaluated for:

• Structural adequacy (will reinforcement be required?)
• Roof condition (damages, leaks, proper installation, signs of aging)
• Approximate life expectancy (check permit records when available)
  

If you’re a homebuyer or agent, check permit history if available and ask the question early — not during due diligence.

Remember: Solar is a long-term investment. The roof needs to be worthy of it.‍

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The Smart Move: Replace Together

If the roof is near the end of its life, the most efficient path is often combining the projects.

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Here’s why:

1. You align lifespans.

New roof. New panels. One clean 20–30 year runway without the staggered additional costs of having to remove the panels during a roof replacement 5 years after they were installed.

2. Coordination reduces friction.

Many solar installers work directly with roofing contractors. Sequencing is tighter. Penetration details are cleaner during installation. Structural upgrades are more accessible. From a building-science standpoint, this matters. Every roof penetration is a water-management detail. Flashing, sealants, and attachment points need to be executed properly — especially in a snow-heavy climate like ours; and this is just easier to accomplish when both systems are being installed at the same time.‍

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For Real Estate Agents: The Value of Solar

A properly owned solar system can absolutely be a selling advantage. Buyers understand lower utility bills. They appreciate energy independence. And data suggests owned systems often command a premium.

But here’s where transactions can get complicated:

Owned systems

– Typically add measurable value. Studies show that buyers are often willing to pay a premium of about $15,000 for a home with an average sized, homeowner-owned solar array.

– Transfer cleanly with the property.

Leased or PPA systems (third-party owned)

– May not increase sale price.

– Require contract transfer.

– Can slow down underwriting or buyer comfort.

If you’re listing a home with solar, clarify:

• Is it owned outright?
• Is there a lien?
• What’s the remaining term?
• What’s the documented production history?
  

Appraisers may use valuation tools to quantify system contribution — but clarity drives confidence. And confidence drives smooth transactions.‍

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Roof Suitability Still Matters

Not every roof is ideal for solar. And installers and homeowners need to be upfront and honest about the details.

Performance is influenced by:

• Orientation (south-facing performs best in our latitude)
• Roof pitch (slope between 15-40 degrees is optimal)
• Shading from trees or adjacent structures (community solar options may be considered)
• Available unbroken roof surface
• Structural capacity
  

If a roof is shaded heavily or chopped up with dormers and valleys, system efficiency drops.

In some cases, community solar may make more sense than rooftop panels.
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Where to Start

Whether you’re a homeowner exploring options or an agent advising a client, the sequence should look like this:

1. Have your roof evaluated by a qualified roofing contractor or home inspector.
2. Determine remaining life.
3. Assess structural and shading conditions.
4. Then bring in qualified solar professionals.
   

Treat the roof and the solar array as a single integrated system. Because they are.

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For more information regarding residential solar installations visit: https://www.energy.gov/eere/solar/homeowners-guide-solar

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