Founder | BPI® Energy Auditor Certified Professional

Achieving maximum energy efficiency in a home benefits the environment and helps reduce your energy costs. Even small changes help accrue savings, but energy efficiency begins when selecting the house.

With modular homes growing in popularity, you might wonder if they are as energy-efficient as their traditional or “stick-built” counterparts.

This article will explore the differences between modular and stick-built homes’ construction and features that impact efficiency. But first, we’ll explain precisely if a modular build is more energy-efficient from the get-go.

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Are Modular Homes More Energy-Efficient Than Traditional Houses?

Modular homes are generally more energy-efficient than stick-built homes. Manufacturers assemble them in a factory, where they are tightly built and protected from the weather. You can also custom-order more efficient options as well.

What Makes Modular Homes More Energy-Efficient?

Energy efficiency isn’t just about finding the right equipment. If the home itself isn’t set up for success, the equipment may not perform optimally.

Modular homes, also known as prefab homes, are more energy-efficient than traditional homes due to their factory construction. In a controlled environment like a factory, the house is pieced together with greater precision and minimal errors, ensuring fewer defects that might negatively impact energy efficiency.

A modular home is assembled in a factory

Some things in a home that will impact efficiency include:

Quality of framing – there are ways to frame a home that uses minimal lumber without compromising structural integrity. Less framing means more room for insulation, which strengthens energy efficiency.
Doors and windows – air escapes through and around doors and windows, so you must ensure these building envelope components are adequately sealed. Many doors and windows are also designed with energy efficiency in mind.
Ductwork – hot and cold air travel through ductwork before coming through the vents in the home. If the construction crew doesn’t properly seal the ductwork, air escapes before reaching the home’s interior. As a result, air pressure is lost, dramatically reducing efficiency.
Gaps and crevices – any area in the home that allows air to escape is a potential weak spot.

With a good manufacturer and quality materials, modular homes can excel in these areas. Let’s discuss more in-depth the energy efficiency of modular homes.

Precise Construction and Assembly From the Factory

Traditional contractors and home builders undoubtedly do a lot of calculations and measurements to ensure that they assemble a house correctly. However, modern factories are more sophisticated than ever, and outperforming complex machines and computers isn’t easy.

To understand just how tight construction is for modular homes, consider the following:

Prefab homes are mass-produced, so construction must be tight and precisely calculated to keep consistent results.
The pieces of a modular are assembled on-site, and if calculations aren’t exact, the pieces won’t fit correctly.

Additionally, modular homes adhere to the same guidelines and building codes as traditional homes, so they are constructed to the same standards while being built in a much more controlled environment.

Precision in the factory ensures that everything is tightly connected and sealed. As a result, modular homes tend to have fewer gaps and crevices for air to escape, making it easier for the house to hold a temperature. In other words, keeping your home airtight maximizes the potential of your HVAC system.

Quality control is much easier in a factory where you know exactly when and where everything takes place. This environment is much more predictable than a construction site, where several things can go wrong.

Factory construction eliminates many problems and inefficiencies with traditional build sites, making modular construction more reliable.

Prefab Houses Have Enclosed, Airtight Design

For mass production, prefab manufacturers typically opt for simple designs, with many modular homes being just a basic square or rectangular shape. While layouts have gotten more elaborate over the years, this remains true for many companies.

A modular home's backyard with a pool in the foreground

One of the benefits is fewer connection points and, therefore, fewer spots for air to escape. Depending on the size of the home, there may only be two sections.

Sections of the home are assembled on-site and should fit together seamlessly. The resulting structure is tightly enclosed and optimally insulated to ensure maximum energy efficiency. Sometimes, the house may be small enough to deliver in one piece, which is even better.

Stick-built homes are technically “enclosed” at the end, but you rely on people to seal off every opening and seam bit-by-bit. They’re working outside and on ladders or platforms; the process is far from perfect.

On the other hand, components of a prefab home travel through an assembly line without any external factors that might affect the quality of work.

Modular Homes Offer Factory-Assembled HVAC Systems

If you’re using a forced-air system for your heating and cooling needs, manufacturers may also install the ductwork necessary for this system at the factory.

Granted, this might depend on the builder and the package you select, but a pre-installed ductwork system is another potential energy-efficiency advantage of a modular home.

This benefit is because duct systems must be appropriately sized and adequately sealed to be effective. Duct systems typically consist of many small sections that get put together, and if the connection points aren’t sealed properly, air escapes before it even reaches the vents.

Air loss in the ductwork also reduces air pressure, lowering airflow, which will force your furnace or air conditioner to work harder.

Sometimes, the manufacturer will insulate the system to prevent air loss. Regardless, if your duct system gets installed at the factory, you can be confident that it will install the system with efficiency in mind.

Limited Room for Human Error

No matter how good the contractor building your home is, there will always be errors made as a result of miscommunication, miscalculation, or something else entirely.

While these mistakes are still possible with prefab homes, their potential is significantly reduced, given that machines do a large portion of the work.

Alternatively, many people and contractors are involved in constructing a stick-built home—the more individuals working on a project, the more opportunities for something to go wrong.

Additionally, the environment in which modular homes are built is climate-controlled. Stick-built homes are exposed to the elements. Depending on the length of construction, materials might warp or degrade due to rain, snow, or sunlight.

This exposure doesn’t necessarily affect future energy efficiency, but in severe cases, this might affect how well individual pieces fit together.

Options for Additional Modular Energy-Efficient Features

The customization potential for modular homes has grown over the years, and these days, you can tailor your home in almost all the same ways as a traditional stick-built home. These customizations include:

High-quality materials – modern prefab homes can be very upscale. You can often get some of the best lumber, insulation, and flooring materials to improve the home’s strength, comfort, and energy efficiency.
LED Lighting – if the manufacturer offers lighting options, you can select the most efficient lights.
Better doors and windows – some doors and windows are designed with energy efficiency in mind, and these features ensure that your home stays insulated even in the most vulnerable areas.
Smart technology – some manufacturers might offer intelligent technology, like smart thermostats, as an add-on feature. Smart technology gives you greater control over the systems that consume the most energy.
Solar panels – some manufacturers design modular homes to be more or less self-sufficient, while others offer solar panels as a potential add-on feature.

Modular homes offer tighter construction due to factory fabrication, but you also have opportunities to add features to improve energy efficiency even further.

Many Prefab Manufacturers Focus on Energy Efficiency

If you think about it, everything about a modular home is efficient. Manufacturers assemble the houses indoors, where quick and streamlined production produces very little waste. They also transport the structures to the property in just a few pieces.

With that in mind, it’s no surprise that many modular home manufacturers use energy efficiency as a selling point, perhaps even more so than traditional contractors.

You can easily find companies that offer energy-efficient designs, sustainable materials, and other high-performance features. These manufacturers also make it easier to integrate energy-efficient HVAC systems, solar panels, and other environmentally-friendly equipment into their home designs.

an aerial view of a modular home with solar panels on top in the dessert

Builders often design prefab homes to be net-zero, meaning they produce enough renewable energy to cover the home’s needs.

Stick-built homes can’t achieve the level of production efficiency of modular homes. Extra equipment must be retrofitted or installed after builders complete the house, which lengthens project times and adds cost.

When you purchase a modular home, all of this gets included from the beginning, and the house is complete when it reaches your property.

Modular Homes are Often Energy Star-Certified

The government distributes Energy Star certifications to homes that meet specific guidelines they have set in place. They have indicated that Energy Star-certified homes are at least 10% more efficient.

To receive the certifications, a modular dwelling might need:

Additional exterior sealing
Recessed lights
Increased insulation
Proper ventilation
Thermal-efficient windows

Most of the required features work toward making the home even more airtight. While stick-built homes can implement the same techniques, modular builders can often do so with less effort.

Depending on your package, some prefab homes are equipped with Energy Star-certified appliances. As a result, you can ensure you’re running the most efficient equipment throughout the house, from lighting to HVAC equipment.

Are Modular Homes More Energy-Efficient Than Mobile Homes?

While they sometimes might appear similar, modular homes are different from mobile or manufactured homes. They differ in construction methods, building code requirements, comfort level, and energy efficiency.

Modular homes are more energy-efficient than mobile homes. Mobile (or manufactured) homes don’t have the same building requirements and may not achieve the same standard as modular or stick-built homes. Therefore, they are typically going to be less energy-efficient.

The main difference between a modular and manufactured home is that modular must meet the same state building codes as on-site homes. On the other hand, manufactured homes only need to ascribe to the federal code set by the Department of Housing and Urban Development (HUD).

That said, manufactured homes have improved over the years; some are even Energy Star-certified.

Additional Advantages of a Modular Home

Energy efficiency is just one of the many benefits of purchasing a modular home.

Some of the other benefits include:

Less build time, so you’ll move in quicker
No weather delays
They are often cheaper to produce
Retention or appreciate of value over time
Equal, if not more, durability than stick-built homes
Less waste production

Additionally, modular homes are great for remote locations where establishing a whole construction site may not be practical. It’s not uncommon for a contractor to transport a modular home long distances, so this could be a good option if you live in a remote area.

Whether or not you should purchase a modular over a stick-built home depends on several factors, including your preferences and lifestyle requirements.

If energy efficiency is essential to you, a modular home complete with high-efficiency equipment, heavy insulation, and extra exterior sealing may be the route.

That said, modular homes may be inferior in terms of customizability. While modular homes retain their value, they can also be difficult to resell due to certain negative stigmas.

Regardless, it’s worth assessing the pros and cons of each type of home before investing.

Conclusion

In terms of energy efficiency, modular homes tend to outperform traditional stick-built houses. This advantage is because modular construction occurs in a factory, where the assembly is exceptionally tight and calculated.

In addition, modular homes feature an enclosed design and are heavily sealed and insulated to ensure the interior remains airtight.

Many modular builders prioritize energy efficiency and include high-efficiency lighting, HVAC, insulation, and windows.

Modular homes have some drawbacks, but they are an excellent option if you are trying to maximize energy efficiency or achieve self-sustainability.

Are Modular Homes More Energy-Efficient Than Traditional?