The foundation is one of the most critical parts of constructing a home, requiring durable materials for a rock-solid structure that stands for years to come.
A 2021 study commissioned by manufacturing company 3M found that 70% of homebuyers want to use green materials for their next renovation project. Of those, about 90% are between 18 and 40 years old.
With concerns for the environment ramping up, more buyers expect builders to skew toward eco-friendly foundation materials during home construction.
Homeowners may get excited about living in an environmentally friendly house, but they may not know what makes certain materials more sustainable than others. They may be unsure how various methods for pouring a foundation can make it more durable and long-lasting.
Building Green From the Ground Up
Building green means various things to different homeowners. For instance, some people may integrate smart technology and appliances for optimal energy efficiency or install solar panels on their roofs. Others may improve the landscaping around their home with native plants and a large shading tree to prevent excessive heat indoors.
Of course, if you're building a green home from the ground up, you have more sustainable selections at your fingertips. However, since pouring a foundation is the first step in the building process, deciding early on what type of eco-friendly materials you want your home to sit on is essential.
A solid foundation should be adequately compacted to withstand approximately 50 tons — the weight of an average-sized house — and wind effects. Otherwise, homes risk lifting, shifting, sliding and collapsing over unsteady surfaces. The foundation must also counter soil pressure, frost expansion, and excess moisture, vapors and radon.
Additionally, the foundation plays a role in your home's energy conservation by helping adjust the temperature comfortability. Therefore, you should consider an insulated foundation to prevent heat from escaping from the walls, slabs and crawl spaces.
Eco-Friendly Foundation Materials: What Are Your Options?
Choosing your foundation materials means you're officially ready to break ground — an exciting time for homeowners engineering a sustainable structure from the ground up. If you're wondering what options are available for pouring a foundation, you might consider one of these three eco-friendly possibilities.
1. Concrete Slab
There's a reason why concrete is a preferable choice for building resilient communities. For starters, concrete is the most durable in all climates, including areas prone to natural disasters and extreme weather events. It's also nonflammable, won't cave under soil pressure, and is resistant to rot, mold, warping and sagging — even with moisture exposure.
To better understand concrete's sustainability, consider how long concrete-poured homes remain standing. Because concrete lasts for decades — 40% of homes in the United States are nearly 50 years old — it carries a relatively low environmental footprint. It's also 100% recyclable and reusable at its end-of-life cycle.
Even better, when builders use pumped concrete instead of a chute for pouring a foundation, you lessen your risk of cracks and shrinking over time, enhancing its durability and longevity.
A concrete foundation will be the most stable option if you're a homeowner intending to assemble a prefabricated home. These are built off-site in climate-controlled manufacturing facilities and delivered in completed sections to the property — another eco-conscious alternative for homeowners who want a fully green home from start to finish.
2. Frost-Protected Shallow Foundation
Let's say you're building a home in a colder climate with record annual snow and ice accumulation. You may want to go with a frost-protected shallow foundation.
Frost-protected shallow foundations allow for shorter 16-inch foundation depths, using foam insulation to help elevate the frost depth. Over the last four decades, Scandinavian countries have utilized this alternative foundation in over 1 million homes.
Builders refer to the air-freezing index (AFI) to determine how severe the winter season is wherever home construction occurs. The AFI measures the cumulative temperature days that fall below 32 F over 11 years and delivers an estimated depth of maximum ground frost for the foundation.
Frost-protected shallow foundations are ideal for homesites with low to moderate sloping grades. Homeowners who opt for frost-protected shallow foundations may save about $8,000 to $10,000 more than they would spend on the cost of conventional slabs. Still, newer insulating concrete forms (ICF) may provide greater resilience and energy efficiency.
3. Insulated Concrete Form (ICF) Foundations
Basements typically have multifunctional purposes — on the one hand, an unfinished level may serve as additional storage or double as the laundry room. Other cellars contribute extra square footage for living space, such as a family room or guest suite with bedrooms, finished bathrooms and a kitchenette — making comfort and energy efficiency critical.
Although home construction with ICF foundations has occurred since World War II, they've grown in popularity over the years as a sustainable construction material. Homeowners can reap the benefits of concrete — more outstanding durability and disaster, rot and moisture resistance — but with added insulation and noise-blocking powers.
Engineering an ICF foundation requires pouring concrete between stacked or connected foam panels, while some builders may prefer hollow blocks instead of foam paneling. Meanwhile, greener composites are also available for the eco-conscious homeowner to consider.
Composite ICF panels mix recycled expanded polystyrene (EPS) with cement — a weightier block requiring less support during construction. Common composite ICFs include:
- Rastra: Made from 100% post-industrial waste
- Nexcem: Wood-fiber composite blocks
- Faswell: Uses mineralized wood chips from recycled wood and cement
Another perk that may entice homeowners to go with an ICF foundation is its ability to lower energy bills by 50%. ICF can also cancel noise by two-thirds more than conventional framing materials if used within the rest of the home's construction.
Pouring a Foundation With Green Materials
Engineering your house with environmentally friendly foundation materials is wise if you're interested in saving energy and lowering your home's carbon footprint. Of course, choosing the most suitable materials is crucial, largely dependent on your region's weather conditions, the type of house you're building and your needs for energy efficiency. Discuss your foundation with an experienced contractor who can guide you toward selecting the most durable, sustainable option.