How to heat a large old house efficiently

Heating options for old houses have improved, and there are plenty of modern, efficient HVAC options for older houses.

And if you’re not quite ready to finance a new heating system? Fear not: There are still good ways to reduce the cost of heating your older home.

Here’s what we’ll cover in this article:

• Common challenges heating a large old house efficiently
• 3 steps to efficiently heat an older home
• Heating options for old houses
• How air sealing your home and insulation upgrades can stop drafts permanently 
• Why heat pumps are the best way to heat an old house

Basically, in this guide, you’ll learn how to finally get warm in your old house (as well as get all the information you need about smart HVAC options for old houses).

Ready to stop watching TV in a parka? Let’s dive in.

How to heat a large old house—Common challenges with heating an older house

First, the major challenge of heating an older home: Cost. 

The price of heating your house varies quite a bit and depends on where you are, what type of fuel you use, and what energy costs in your area, but heating—in general—is expensive.

According to Energy.gov, heating your home typically makes up about 42% of your utility bill (1). That’s quite a lot.

Not to throw fuel on the fire, but energy costs have risen in the last couple years, too, which makes your heating bills even more pricey. (And if you own a drafty old house, you know that your winter bills can really skyrocket.) Read Why is natural gas so expensive? to learn more.

But why does heating an old house cost so much in the first place? There are a few potential villains, but we’ll start with the decoy first.

If your windows are a big part of the problem, it doesn’t necessarily mean you have to replace them.

Old, drafty windows

Most people think their old windows are to blame for the drafts in their home, and that’s understandable.

Window companies have spent plenty of money convincing homeowners that their windows are the source of all their climate control issues. 

But—surprise!—windows usually aren’t the primary culprit. In fact, there are plenty of other reasons your house could be cold (and you’ve likely personally encountered them if you own an old home). 

Something else to note, too: If your windows are a big part of the problem, it doesn’t necessarily mean you have to replace them. In fact, you probably shouldn’t!

In many cases, a better option is to air seal your windows with a technique called weather stripping. (You might be able to get this done at no upfront cost.)

Read Do window insulation kits work? or Do thermal curtains work? to learn more.

Gaps in your home’s construction

Old houses are full of holes, gaps, and crevices that cold air can slip through. These aren’t gaps that are easy to see, but they’re there nevertheless—and they can make your house feel absolutely freezing inside. 

That’s why old houses are drafty—the construction is old and has had time to deteriorate (in even the best old home). Cold air can come in through the attic, holes in the walls, the exterior walls, and the windows. And if you have an untreated fireplace with a chimney, don’t be surprised to find that you get cold sitting by it—it’s a magnet for cold air. 

Learn how to find air leaks in your house.

Old insulation

Another common issue is insulation.

In older homes, it’s often old or of low-quality, and in some cases, it might even be non-existent. If you’re not sure what your insulation situation looks like, you can get a professional to check it out. 

(Don’t forget to check on your attic insulation, too—that’s important. We’ll talk more about that later in the guide.)

An underperforming heating system

The elephant in the room is that, sometimes, your heating system just isn’t up to the challenge of warming your entire home.

After all, old homes were designed for old heating systems. They’re often heated with boilers and radiators that haven’t been serviced correctly or that use tons of energy—only to make a marginal difference in how your home feels.

These older heating systems are also powered by fossil fuels—which is bad for the environment, your local and home air quality, and your energy bill, depending on the home heating system type you use.

Here are 3 steps to efficiently heat an older home

The truth about heating a large old house is that it’s going to take a little bit of work—and it might even take some financial investment.

There’s a chance you’ll need to upgrade your insulation (or even your heating system) in order to fully resolve the problem.

The good news? You have options—probably more than you think.

In fact, it’s almost always a good idea to see if you can resolve the problem by trapping in the heat you have. (In many cases, this can make a significant difference in how your home feels.)

And there’s even more good news: In some places, you may be able to warm up your older home without paying any upfront costs.

Now, take a look at your three most important options.

1. Stop cold drafts in an older home

On the surface, this option is fairly straightforward: Find where the holes are, and then plug them with something so that cold air can’t get in (and warm air can’t get out). 

There are two big strategies to do this—one is temporary and the other is permanent. 

First, the DIY option.

To temporarily inhibit cold drafts, you’ll need to identify areas where cold air is getting in. Likely candidates include the edges of doors and windows and your HVAC vents.

Then, you’ll need to buy, borrow, or rig-up appropriate “air sealers” for each of those issues. Search around online and you’ll find plenty of products, such as draft stoppers for the bottoms of doors, magnetic vent covers, and plastic window sealers. 

Air sealing is so effective that the EPA estimates that air sealing alone can save you up to 15% on your monthly heating bill.

ENERGY STAR

Another common area for cold air to get in is through an unused, unsealed fireplace—these are basically super-highways for cold air.

To temporarily solve this problem, you can try installing a chimney balloon, a fireplace blanket, or a chimney cap. Or, if you never use your fireplace, you might even permanently seal it off.

There are plenty of possible solutions here, but no matter how you deploy them, there’s still an underlying issue—draft stoppers don’t solve the real problem. 

So let’s talk about a solution that does.

Permanently stop drafts (and minimize heat loss) through air sealing your home

Here’s an inconvenient truth: If your old house is too cold in the winter or too warm in the summer, you probably shouldn’t blame your door jambs and windows.

Instead, there’s a good chance the culprit is your attic—more particularly, the way your attics are insulated (or not insulated) as well as all the gaps and crevices in your roof and ceilings. 

Why is your attic the likely culprit? Well—channeling our third-grade teachers here—heat rises. And when the heat energy in your old house rises, it’s supposed to be kept inside.

But if your attics aren’t well-insulated—and if your old house hasn’t been sealed by a professional—the heat energy simply escapes through the roof. When it does, it creates a giant vacuum effect, called the stack effect, which pulls in cold air through all the other gaps in your home.

(If you’ve ever wondered why cold air seems to stream into your home through any available crevice, now you know—it’s literally being sucked in.)

In winter, about a quarter of the average home’s heat is lost through the roof. And that percentage can go even higher for an older home, because of the way that old homes are constructed.

And that’s why a major step toward keeping your old house warm is air sealing.

If you’ve never heard of it, a quick explanation is that it’s the process of finding and sealing off all the little holes in your home which let in the cold air.

Some of those holes will be in your doors and windows, sure, but many of them will be in your attic, your roof, your basement, and your crawlspaces—all the places you may not have checked (and, frankly, probably don’t feel like inspecting, because they aren’t fun to get to).

Air sealing is a good idea for just about every home, and you can learn all about it in our Complete Guide to Air Sealing.

However, although air sealing is effective, it can be difficult to implement it yourself correctly.

If you’re not trained in this specialized work, you could risk over-sealing your home or not sealing it properly at all, wasting materials, time, and your own elbow grease!

In short?

If you’ve got a ton of cold air in your home, there’s a good chance that air sealing your foundation, your attic, and the rest of your home will go a long way toward making you feel a lot more comfortable.

(And, if you live in certain areas, you can often get this air sealing work done at no upfront cost.)

2. Add insulation to an older home

If you’ve got an old house, there’s a good chance that much (or all) of the insulation you have is outdated or of poor quality.

Insulation technology has progressed a lot in the last few decades, and upgrading yours could make a huge difference in your overall comfort level.

And even if your insulation is decent, you may need to check to see if it is, indeed, everywhere in your home. A lot of older houses and historic homes have unfinished and uninsulated attics that can let a whole bunch of cold air in if left unaddressed.  

This is also exactly why your upstairs is so hot in the summer. In the summertime, heat radiates from poorly insulated attics into your house. (Read How to Cool the Upstairs of a 2 Story Home to learn more about keeping your top floor cool.)

Areas of your home that might need additional insulation

The best way to determine where your home might need additional insulation is by going through an energy audit—a systematic process for determining how and where your house is losing its heat energy.

You can attempt to do an energy audit yourself—some people do—but we’ll be honest: This is a big ask if you’re not an energy expert.

However, scheduling a professional energy audit is simple and can be completed at home or through a remote evaluation with provided photos.

At Sealed, we find our customers are fans of the remote option, receiving an expert determination on their own schedule—without making additional appointments to meet someone in your home.

An energy audit is often available for free from your local utility company, but, if it isn’t, you can usually get one for a reasonable price from a specialist in your area. (For what it’s worth, if you go with Sealed, it’ll be included in your overall package—no need to do anything extra.)

Read How does insulation save energy? to lean the science behind the upgrades.

Create a thermal boundary by insulating your attic

This is a big one. As you’ve seen, your attic could be one of the biggest reasons your house feels freezing, so creating a thermal boundary with insulation can go a long way to making your space comfier. 

The materials used in your basement and foundation are excellent bridges (thermal bridges, if we’re getting technical) for cold to seep into your home.

Insulating your basement walls properly can mitigate this issue, as well as provide some other benefits (such as some protection against moisture intrusion).

Many people think they need to replace their windows, but, often, just making sure they’re well insulated and air-sealed is all that’s needed. (Really!)

3. Choose the best heating system for an old house

Okay. Let’s say you’ve sealed and insulated your home (or at least plugged some of the holes)—and the temperature still isn’t what it needs to be. Or maybe it’s cold in one room and warm in another.

It’s time to move on to the next strategy: a new heating system. Don’t panic, though. We know it’s a big investment, but it’ll be worth it, it’ll add to the value of your home, and you might even be able to get your new energy-efficient heating system without paying anything upfront.

A quick word of warning before we get into the options: Don’t try to size and purchase a heating system on your own.

When you’re considering heating options to heat a large old house, it’s vital that you work with someone who knows what they’re doing. (You don’t want to make a significant investment and find out later that you didn’t solve the problem.)

You could cut up to 50% of your energy use when getting high-performance insulation, professional air sealing, and heat pump HVAC upgrades with Sealed. Learn how.

Ways to heat an old house

First, a quick note about your heating upgrade strategy. Many folks assume that just purchasing the newest version of their current heating system will be the most efficient use of their upgrade dollars.

But times have changed, heating technology has improved significantly, and if you want to get the biggest bang for the buck, you should seriously consider newer, more energy-efficient heating options.

Let’s talk through the main heating options for old houses:

Heat pumps—air source and geothermal heating pumps  

We’ll start with the best. In most cases, heat pumps are the most efficient way to heat your older home.

They work by transferring heat from outside your home to the inside of your home and they also double as an air conditioning system in the warmer months—a win-win. Learn more about heat pumps in The Ultimate Guide to Heat Pumps.

Boiler/radiator

These heat water until it turns to steam. They run on electricity, gas, or oil, and are very common in older, historic homes. (Unfortunately—and you might know this from personal experience—they’re not very efficient.)

Electric floor heating

Also known as baseboard heaters or electric resistance heating, these are units which can be individually installed in rooms that need extra heat. They’re not a great whole-house solution, though.

Radiant, localized heating

The quick-and-dirty solution: Just buy a portable heater and set it up in the room that’s cold. While this can work as a temporary fix, it’s one of the least effective, least aesthetically pleasing, and least efficient options.

Furnace

The most common type of heating in the US. Furnaces work by generating heat on burners inside a cabinet, and they can run on electricity, natural gas, or oil.

Floor heating

This kind of system spreads heat through a film or mat beneath your floor (or, sometimes, through heated water in pipes). If your old house doesn’t already have this, it can be an enormously intrusive installation process.

For a more in-depth (and really helpful!) guide to all your home heating options, tap here.

Converting oil-powered heater to electricity

Before we move on, there’s one more option to talk about—and it’s one you may not have even considered: Converting your oil-powered heating system into an electricity-powered system.

Many older homes have oil furnaces or boilers, and if you have one, you might have gotten used to constant oil deliveries (and very short, lukewarm showers).

But it doesn’t have to be this way. In many cases, your home heating system can be converted to run on electricity, a much cleaner, safer and more energy-efficient way of keeping warm.

Converting from oil to electric can make your home far more valuable to buyers (because they don’t want your old oil-based system any more than you do).

Finally, new electric air source heat pumps are much more efficient than old oil-based technology or electric furnaces of the past, which means you’re going to get more heat for the energy you purchase if you convert to a heat pump.

Overall, electricity is better for you, better for your home, and better for the planet.

Why electric heat pumps are a leading choice in heating options for old houses

Full disclosure: We’re big fans of heat pumps in general, but to be fair—we’ve got good reasons.

Heat pumps are the most efficient way to heat just about any enclosed space, they’re quiet and comfortable, they lower your heating bill significantly, and they double as an air-conditioning system in the summer.

When it comes to old homes, though, heat pumps shine even brighter. Here’s why:

Put simply: They feel great. Heat pumps provide beautiful climate control, they don’t smell, and they provide a constant circulation of fresh, filtered air.

1. Heat pumps don’t require an intrusive installation process

There’s no need to install ductwork—or do anything truly intrusive—when you install a heat pump system. (Though if you’ve got ductwork, it’ll work with it!)

This makes a heat pump system perfect for older homes with irreplaceable architectural features and fragile construction. 

Just an FYI, if you go with a ductless option, they’re often called mini splits, mini split ac, or ductless heat pumps. Learn how to incorporate ductless mini split units into decor here.

2. Heat pumps serve a dual purpose (and don’t require as much maintenance)

Heat pumps are a two-for-one deal—when you install a heat pump system, you’ll get efficient, comfy air-conditioning, too (which means even less disturbance to your old home).

3. Heat pumps offer room-by-room temperature control

With modern heat pump technology, homeowners can better regulate specific temperatures throughout the home.

Traditional one-zone heating and cooling systems are usually found in older homes, which don’t allow you to regulate temperatures based on individual spaces or rooms.

Love having your living room warmer, while the bedrooms stay cooler? Not a problem with a mini-split heat pump! Upgrading to a heat pump gives you more flexibility and control.

4. Heat pumps use modern technology that runs on a safe power source

Old houses often come with old technology, such as boilers—which come with the risk of explosion—or systems powered by flammable, dangerous fuels.

Heat pumps use electricity, and not very much of it, so your home will be safer, cleaner, and smell fresher.

If you’re considering making the leap to convert from heating oil to natural gas, why not take the next step (eliminating additional energy conversion later on) and choose a system that runs on clean energy?

5. Heat pumps can make old homes feel like new ones

There’s an intangible benefit to heat pumps that’s hard to explain until you sit in a home that has one. Put simply: They feel great. That means you can finally fix that stale air in house feeling that nobody likes.

Heat pumps provide beautiful climate control, they don’t smell, and they provide a constant circulation of fresh, filtered air. (An additional benefit? They’re super quiet.)

6. You might be able to get one for no upfront cost

Finally, depending on your situation and location, you may be able to get your heat pump without paying anything for it at first.

In fact, qualifying homeowners can get both air sealing and a heat pump system—then pay for it later with energy savings. It’s a great way to get the energy-efficient upgrades you need without draining your bank account. See if your house qualifies.

Want to talk about air sealing or heat pump systems for your older home?

Give us a ring at 888-985-7481 to talk with one of our specialists and to see what upgrades might be right for you and your situation. (There’s never any pressure to use Sealed, either. If we’re not right for you, we’ll let you know.)

Want to go ahead and jump in? You can get a quote for home comfort upgrades like professional air sealing, high-performance insulation, and heat pump HVAC systems if your home qualifies. Take our quick (and fun!) quiz to find out!