Michigan's 2025 Energy Code Update: What Custom Home Buyers Need to Know

Michigan rolled out a significant update to its residential energy code in April 2025, and if you're in the market for a custom new construction home, it's worth understanding what changed — and why it actually works in your favor. For buyers looking at communities like Oaks of Tyrone in Tyrone Township or anywhere in Southeast Michigan, the updated code raises the floor on energy performance, lowers your monthly utility bills, and ensures your new home is built to a higher standard than the vast majority of existing housing stock in the area.

Here's what the updated code means in plain language, how it affects the home you're considering building, and why it matters more than most buyers realize.

What actually changed in Michigan's energy code?

The updated Michigan Residential Energy Code, effective April 22, 2025, builds on the state's adoption of the International Energy Conservation Code (IECC) with Michigan-specific amendments. The key changes affect how new homes must be insulated, sealed, and ventilated — and they represent the most meaningful update to residential energy standards in the state in several years.

For custom new construction homes, the most impactful requirements include:

• Tighter building envelope standards: New homes must meet stricter air-leakage requirements, meaning less conditioned air escapes through walls, attics, and foundation joints. This is one of the biggest drivers of energy savings in modern construction.
• Enhanced insulation minimums: Wall, attic, and foundation insulation R-values have increased, requiring builders to use more insulation — or better-performing insulation — than previous code versions demanded.
• Higher-efficiency HVAC requirements: Heating and cooling equipment must meet updated efficiency ratings, ensuring your system uses less energy to maintain comfortable temperatures throughout Michigan's heating and cooling seasons.
• Energy-use monitoring provisions: The updated code includes provisions for energy-use metering in certain residential construction, giving homeowners visibility into how much energy different systems in the home consume.

These aren't minor technical adjustments. Collectively, they mean that any new custom home permitted after April 2025 in Michigan is held to a measurably higher energy standard than homes built even five or ten years ago.

Why this matters for custom home buyers in Southeast Michigan

If you're comparing new construction to resale homes in the Fenton, Tyrone Township, or Livingston County area, the updated energy code widens the gap in a meaningful way. Most resale homes in the area were built under earlier code versions — or before energy codes were enforced with the same rigor. A 15-year-old resale home in the Fenton area might have insulation installed to 2005 standards, single-pane or early dual-pane windows, and an HVAC system that's rated well below current efficiency benchmarks.

A new construction home built to 2025+ Michigan energy code standards will use significantly less energy — not just compared to that resale home, but compared to homes built under the previous code version. The Department of Energy estimates that modern new construction homes use 30–40% less energy than homes built before 2010, and each code update pushes that number further.

In practical terms, that translates to lower monthly utility bills — a real number you'll see on your statements every month, not a theoretical projection. Over 10 years, the energy savings between a code-compliant new construction home and an older resale home can total $15,000 to $25,000 or more, depending on home size and usage patterns.

How Big Sky Development builds beyond code

Meeting the updated energy code is the minimum requirement. Big Sky Development has been building to high energy-performance standards long before the 2025 code update, and their approach at Oaks of Tyrone reflects that track record.

Every home at Oaks of Tyrone includes:

• 2×6 exterior wall construction: Thicker wall cavities allow for more insulation than the standard 2×4 framing used by many production builders, improving both thermal performance and sound insulation.
• High-efficiency Carrier heating and cooling systems: Carrier is one of the most trusted names in HVAC, and Big Sky's specification of high-efficiency units ensures your heating and cooling costs stay low year-round.
• Community septic system with pre-treatment: A modern engineered septic system is both an environmental and long-term maintenance advantage compared to conventional systems.

Beyond the systems, Big Sky's 30-plus-year track of building custom homes in Southeast Michigan means they've adapted to every code change, weather pattern, and material evolution since 1994. The updated energy code isn't a challenge for an experienced builder like Big Sky — it's confirmation that the standards they've been building to are now the standard the state requires.

The long-term value equation

Energy efficiency isn't just about monthly utility bills — though those savings are real. It's also about the long-term value of the home you're building. Here's why:

• Lower operating costs increase home value: As energy costs continue to rise, homes with better energy performance become increasingly attractive to future buyers. A home that costs less to operate is worth more on the resale market.
• Comfort is a feature: A tightly sealed, well-insulated home doesn't just use less energy — it maintains more consistent temperatures, reduces drafts, and provides better indoor air quality. Those comfort improvements aren't line items on a utility bill, but they're the difference you feel every day living in the home.
• Future-proofing: Energy codes only move in one direction — stricter. A home built to 2025+ standards will remain compliant and competitive for decades, while older homes may require expensive retrofits to meet future efficiency expectations or buyer expectations.
• Reduced environmental impact: For buyers who care about sustainability, a high-performance new construction home has a significantly smaller carbon footprint than an older resale home — and you don't have to sacrifice comfort or design to get there.

What about resale homes — are they affected?

No. The updated energy code applies only to new construction and major renovations that pull new permits. Existing resale homes in the Fenton, Tyrone Township, and Livingston County area are not required to meet the new standards. This creates an interesting market dynamic: new construction homes are now built to a meaningfully higher standard than the existing housing stock, without any requirement for existing homes to catch up.

For buyers, this reinforces the value proposition of new construction. You're not just getting a newer home — you're getting a home that's built to a standard no resale home in the neighborhood is required to match.

How do you know if your builder is meeting the new code?

Michigan's updated energy code is enforced through the building permit and inspection process. Any new construction permit issued after April 22, 2025 must comply with the updated standards. Your builder should be able to explain which specific code provisions apply to your home, and the local building department will conduct inspections during construction to verify compliance.

At Big Sky Development, the inspection and quality assurance process goes beyond code minimums. The owner personally visits active jobsites to oversee quality standards on every home under construction — an approach that's been standard practice for Big Sky since the company was founded in 1994.

Frequently asked questions