Home Energy Renovations: When You Can’t Go Down To The Studs

A couple of months ago I met with a client who wanted to make significant energy improvements to an older house. But because the house was occupied, it wasn’t possible to go down to the studs to do the kind of deep energy retrofit Project Rebuild is doing in Canton. (If you missed that story in The Leaflet, you can find it here in the October issue.) Still, there were a lot of opportunities to reduce the energy usage and lower their utility bills. In fact, the suggestions I made for that house provide a pretty good checklist for things you might want to consider for improvements at your own home.

First, get an audit

An energy audit will provide you with a clear game plan for the improvements you make and help you prioritize the items that will have the biggest impact. Because air infiltration has such a major impact on energy use, and because holes in the air barrier can be hidden in places that are hard to see, a blower door test is important. An auditor will also bring tools like infrared thermographs, along with training in how to identify home efficiency problems. Dominion East Ohio Gas is still offering audits through for just $50, with rebates on the energy improvement work you have done from their list. You can get more information here Home Performance with Energy Star, though as of this writing they were “undergoing administrative updates”. You could also choose to work with an independent home performance consultant to get a more customized evaluation of opportunities and possible solutions. An audit will help you to develop a comprehensive game plan for your improvements, so you don’t make one improvement only to find that you’ve eliminated a better solution to the next thing you tackle.

Wet Basement? Find the causes and decide how to manage it

This isn’t exactly about energy efficiency, but you need to get a wet basement under control before you do anything else. If you seal up the air leaks in a house with a wet basement, your heating bill may be lower but the house may become much more humid, which can lead to mold growth. So check those gutters and downspouts, slope the ground away from the house, and get your footing drains flowing or have new ones installed. If the situation and budget allows, you may want to dig down to the foundation and have new waterproofing added to the outside walls along with new drains. If the roof needs much work, you might decide if you want to have deeper eaves.

Rim joist insulation

The rim joists, where the floor joists meet the outside walls, typically allow a lot of outside air into your house. Adding spray foam insulation or rigid foam insulation sealed in place with spray foam is a great way to improve your energy efficiency. If you are thinking about finishing the basement, be sure to do this first! This air sealing at the lowest level of the house will help to minimize the stack effect that draws heated air out of your house.

Basement wall insulation

Even if the stud walls in your older house have insulation, the basement walls probably don’t. According to Green Building Advisor, “if you live in Climate Zone 3 or anywhere colder, it’s cost-effective and wise to install basement wall insulation”. Our Zone 5 weather is definitely colder. Rigid or spray foam insulation attached directly to the concrete is a great way to insulate existing basements that doesn’t invite problems with wet fiberglass or rotting studs. If you don’t want finished space, you can use Dow Thermax, which has a fire resistant coating attached. Otherwise, a layer of gypsum drywall will be needed to meet flame spread requirements. You may also choose to put a stud wall between the foam and the drywall to make it easier to run wiring and attach the drywall.

New energy efficient furnace, water heater, and air conditioner

If you are building new, a conventional furnace may not be the answer, but for an existing home simply getting a more efficient furnace makes sense. Improved efficiency with natural gas appliances includes switching from an atmospheric combustion unit to a sealed combustion one with direct venting. Here’s a great article describing the hazards of atmospheric combustion and benefits of sealed combustion: Energy Vanguard You may also want to consider providing more managed fresh air for the people in the house, as you are eliminating the accidental air leaks. A heat or energy recovery ventilator (HRV/ERV) is the most efficient solution for this and a must-have for super efficient new homes. Existing homes may want to consider simply providing a fresh air intake connected to the furnace return air duct, so your fresh air will get warmed immediately rather than first running across your toes in a cold draft the way it does in poorly sealed houses with atmospheric combustion furnaces.

Do you need the chimney? If you have a chimney that was only used for the furnace and water heater which now vent through the basement wall, you may want to remove it. Chimneys often have significant air leaks and are just one more hole in your roof. If you are planning to use the top floor as living space, they also tend to be right in the middle of the attic room. So if you don’t need it, take it out!


Attic air sealing and insulation- on the floor or at the roof

Take care of both air sealing and insulating the top of your house- in that order! If you insulate first it will be more difficult to do air sealing. This is the top half of that stack effect that started down at the basement rim joists. Seal the bottom and the top and the house stops acting so much like a chimney, sending your heated air up to the sky. The system you choose for insulation will depend on whether you have ventilated, unheated attic space or if you want living space right up to the slope of the roof.

Exterior door weatherstripping This is an in-expensive one you may be able to do yourself. If you are re-siding, you might also check to see whether you even need all of the exterior doors in the house.

Maybe NOT new windows Replacement windows are heavily marketed, but they may not be the energy problem they want you to think they are. There are reasons to replace windows, but dollar for dollar, other improvements may save you more energy.

Other Energy Star appliances and WaterSense fixtures

An Energy Star washing machine will use less hot water, and the super-spin cycle will mean your dryer have less work to do too. Water Sense shower heads can also reduce your hot water usage. Water Sense toilets will reduce your water bill, and will save energy at the water treatment plant. To learn more about the WaterSense Label visit the EPA site.

The value of good planning

Most of these projects can be done without disrupting your life while you live in your home. Like all home improvement projects, you will have a better outcome if you remember the house is an interconnected system and you have a good plan in place before you begin. Afterwards, your home will be more comfortable and you’ll have lower energy costs.