Building Green

The Inherent Sustainability of Small Dwellings

In the ever-evolving world of sustainable design, finding sustainable ways to live and build can seem like a complicated puzzle to solve. But what if there were an easy way to lower your impact? Turns out, living in a sustainable home may be simpler than you realize — just think small!

Andrea Detweiler

June 16, 2022

If you’re thinking about remodeling or building a new home with sustainability in mind, what’s the first thing you should consider? There are many facets of sustainability in buildings, including material reuse, mechanical systems, water economy, and daylighting. However, when it comes to carbon emissions, there is one factor that will impact your carbon footprint more than anything else: the size of your home.

How does the size of your home impact your carbon footprint?

Here, we have three examples of homes found in the United States: the Ordinary Homestead, the Compact Cottage, and the Cozy Condo.

The Ordinary Homestead is a detached, standalone house of 2,687 square feet — the average area of a new house built in the United States today. The Compact Cottage is 1,200 square feet, which is large enough for three bedrooms and modest kitchen and living areas. The Cozy Condo is also 1,200 square feet, but in contrast to the standalone Compact Cottage, it’s an apartment-style unit in a building with multiple dwelling units.

For the sake of comparison, each of these examples could house a family of three or four individuals (the national average household size is 3.15).

The inhabitants of each of these dwellings likely wouldn’t significantly change their energy usage behavior based on the size of their home. For example, they would likely use their toaster and coffee maker for a few minutes each day and charge their laptop for a certain amount of time regardless of what size home they live in. When it comes to space heating and cooling, though, the size of the space matters. A lot.

We usually talk about a building’s size in terms of floor area, since that has to do with how our functional needs are met by the space. But when it comes to how much energy it takes to heat or cool a building, it is more useful to think about what we call the envelope area — the total area of all floors, walls, and roofs exposed to the outside air. That’s because each square foot of wall or roof has the potential to lose conditioned air — the air that we’ve spent money heating or cooling — to the outdoors.

The Ordinary Homestead has about 7,800 square feet of envelope area — almost three times the amount of floor area. The Compact Cottage has about 3,800 square feet of envelope area. The Cozy Condo, on the other hand, has just 1,900 square feet of envelope area, and that’s assuming it’s on a corner on the ground or top floor of the building. If it were on a middle floor and/or not a corner unit, it would have less envelope area. We don’t count walls between apartments since the air on the other side of the wall is also conditioned. That 1,900 square feet of envelope in the Cozy Condo is just a quarter of the envelope area of the Ordinary Homestead. That means a quarter of the carbon footprint from space heating and cooling.

The Cozy Condo example has an additional benefit: density. Denser development patterns (like neighborhoods that include townhouses and mid-rise apartment buildings, not just high-rise towers) have better access to public transit, and the associated reduction in personal vehicle use further reduces carbon emissions.

How do you determine what type of home is right for you?

Of course, not every household consists of 3.15 individuals, and every individual’s and family’s needs are different. Some of us may need more space for a home office, hosting guests, or storage, for example. We also have individualized preferences on where we live — a dense urban area, a quiet neighborhood, or a remote locale might appeal to different people. If you simply need more space to live and want to do it as sustainably as possible, consider remodeling an existing house, rather than building new, or consider building a home to the Passive House level of performance.

A home built to Passive House standards — an extremely efficient building standard — uses 40-60% less energy than a conventional building. That would bring the total energy use of an Ordinary Homestead down to the level of a conventionally-built Compact Cottage. One way to look at that is that it provides more space without increasing carbon emissions.

Another way to look at it is that a Compact Cottage or Cozy Condo built to conventional construction standards, without the additional cost and effort of building to Passive House standards, is just as efficient as the Ordinary Homestead built as a certified Passive House.

You can make a studio apartment feel like a spacious estate.

Ok, we might be exaggerating. But when it comes to making a space functional for our everyday needs, good design matters, and it matters even more for small spaces. A few rules of thumb can help make the most of small dwellings.

Manage the “Stuff”

Anyone who has lived in an efficiency-sized apartment, van, or boat knows that good storage design is essential, or clutter will take over the limited space that is available. Effective storage requires careful consideration of storage location, size, and accessibility.

Prioritize Room for Living

An effective space-saving hack is to minimize bedroom size to maximize space in common living areas. We don’t typically spend much waking time in bedrooms, but generous kitchens and living rooms can make a small home feel large.

Integrate Outdoor Space

A well-placed window can make a space feel much larger, and a meaningful connection to the outdoors can multiply how large a home feels, for example, a patio accessed directly off a living space with wide glass doors. Extra points if that patio is covered overhead so you can use it in rainy weather, making that space feel like part of your home even though you don’t need to heat or cool it. The Ordinary Homestead or Compact Cottage are more likely to have access to outdoor space than the Cozy Condo, but it’s not impossible to find multifamily dwellings that have outdoor space — think townhouses.