Building-science-based guidance for Pittsburgh-area homeowners

Save Energy. Improve Comfort. Avoid Costly Mistakes. Many energy-saving projects can be completed by homeowners, but not all advice found online follows good building-science practices. This guide highlights the improvements that typically provide the greatest return for Pittsburgh-area homes and points to high-quality resources for detailed instructions. Every home is different. The best way to determine which projects will provide the greatest benefit for your home is to schedule an E3 Home Energy Assessment. If your household may qualify for free weatherization services, contact  ACTION Housing Weatherization Program.

Where should I begin?

For most homes, the following sequence provides the best starting point:

1. Air seal the house: Focus first on the major air pathways in the attic and basement, then address smaller gaps throughout the home.
2. Add or improve insulation: Insulation works best only after air leakage pathways have been sealed.
3. Correct basement moisture problems: Resolve bulk water and excess humidity before air sealing the basement.
4. Seal and insulate ducts: This is especially important when ducts are located in an attic, garage, or vented crawl space.
5. Improve windows where practical: Storm windows and careful air sealing can provide major benefits at far lower cost than full replacement.
6. Reduce smaller leaks and water-heating losses: Outlets, baseboards, plumbing penetrations, fireplaces, pipes, and water-heater settings all matter.

This guide covers attic air sealing and insulation, basement moisture and air sealing, duct sealing, storm windows, smaller gaps and cracks, baseboards, fireplaces, and hot-water conservation. See also our info on hot water heat pumps and our HVAC buying guidance.

Safety first

Observe appropriate safety precautions for every project. Potential hazards include electrical wiring, knob-and-tube systems, loose conductors, lead paint, asbestos-containing materials, vermiculite insulation, combustion appliances, chimneys, fire hazards, and falls. Wear suitable protective clothing, gloves, eye protection, and respiratory protection. Practice lead-safe renovation methods and call a qualified professional whenever you are uncertain.

Attics: air sealing and insulation

Why it matters. Air sealing and insulating the attic can substantially reduce heating and cooling costs. Warm air escaping through attic leaks creates a stack effect: heated air rises and leaves the house, while cold outdoor air is pulled in through lower leaks around windows, doors, walls, and the basement. In the summer, radiant heat emanating from the roof reaches indoor spaces if the thermal barrier is insufficient.  Fixing the attic interrupts these pathways and improves comfort throughout the home. E3 Pro Tip: Start with the attic access. An attic hatch, pull-down stair, or knee-wall door is often an overlooked thermal and air-leakage weak point. Weatherizing this small area can provide a surprisingly large benefit. Major attic air leaks are often hidden beneath insulation. Begin by looking for gaps and blackened insulation:

• Around recessed light fixtures and electrical junction boxes that penetrate the attic floor
• Around plumbing vents, pipes, and HVAC duct chutes
• Along top plates—the perimeter where interior walls meet the attic floor
• Behind and especially below knee walls
• Around attic hatches, pull-down stairs, and knee-wall access doors
• Around chimneys and flues, which require noncombustible materials and special fire-safe detailing

How to improve these areas. Move existing insulation aside, clean the surface, and seal appropriate gaps with caulk or spray foam. Use metal flashing and approved fire-resistant sealants near chimneys and other high-temperature surfaces. Do not apply ordinary foam directly against hot flues or unprotected recessed fixtures.

• Use the ENERGY STAR Do-It-Yourself Guide to Sealing and Insulating for step-by-step guidance and safety information.
• Watch Efficiency Vermont’s attic insulation instructional video
• Where insulation must cover recessed fixtures, use appropriately rated covers or enclosures and follow the fixture manufacturer’s requirements.
• Weatherstrip attic hatches and insulate their attic-facing side with rigid foam board.
• For pull-down stairs, use a well-sealed insulated cover.
• For knee-wall doors, install weatherstripping, ensure the latch pulls the door tightly against the frame, and attach approximately 2 inches of polyisocyanurate rigid foam to the back of the door.

Common mistakes: adding insulation without air sealing; blocking soffit vents; compressing insulation; leaving attic access points untreated; missing bathroom vent pipe, etc.

Basements: moisture first, then air sealing

Why it matters. Outdoor air often enters through the basement—cold in winter and warm and humid in summer—contributing to discomfort and excess moisture. If the basement is wet or musty, address the moisture sources before tightening or insulating the space. Strategies for reducing water and moisture problems (keeping water out of your home should be one of your highest maintenance priorities):

• Clean and inspect gutters and downspouts two to four times per year.
• Observe your gutters in heavy rain and consider upgrading to oversized gutters where heavy rainfall regularly overwhelms the existing system.
• Extend downspouts so water is discharged at least 10 feet from the foundation and regrade soil so it slopes away from the house.
• If using rain barrels, provide an automatic overflow or diverter that carries excess water safely away from the foundation.
• Where surface water flows toward the house, a shallow gravel-filled drainage swale may help if located well away from the foundation; more severe problems may require a professionally designed interior or exterior drainage system.

After moisture problems are controlled:

• Seal air leaks at the rim joist – the area where the masonry foundation meets the wood framing
• Weatherize exterior basement doors
• Install or improve storm windows at basement windows or upgrade to glass block windows.
• Seal plumbing, electrical, and other penetrations with appropriate caulk or spray foam.

  E3 Pro Tip: Run a basement dehumidifier set at 55% RH during humid months with the drain hose routed to a floor drain.

Duct sealing

Why it matters. Ducts are intended to deliver heated or cooled air to the rooms that need it. Leaks reduce efficiency and comfort and can create pressure imbalances. Sealing is especially important when ducts are located outside conditioned space, such as in an attic, garage, or vented crawl space. In those locations, ducts also need adequate insulation after they are sealed.

• For accessible metal ducts in a basement or garage, seal joints and seams with water-based duct mastic
• Don’€™t forget to check and improve registers area, as explained here.
• Where ducts are hidden or located in difficult areas, consider professional duct testing and sealing.

Windows and storm windows

Why it matters. Adding well-fitted storm windows can improve comfort and reduce heat loss at a fraction of the cost of full window replacement. A single-pane window with a good storm can perform similarly to a basic double-pane window. Even double-pane windows—especially those with conductive metal frames—can benefit from low-e storm windows.

• Check out this U.S. Department of Energy low-e storm-window webinar.
• Additional guidance on how to choose and install storm windows, storm window video.
• If a window upgrade is planned, compare the performance specifications of the available products, choose a high-performance window, and request detailed air sealing around the window frame as part of the installation. Look for a U-factor of ≤ 0.20 (for better insulation against Pittsburgh’s cold winters) and a Solar Heat Gain Coefficient of at least 0.25 to take advantage of passive solar heating. Choosing high-performance windows today will affect your home’s comfort, energy use, and utility costs for decades to come.

Additional gaps and cracks

Why it matters. Reducing the amount of air leaks in and out of your home is a cost-effective way to cut heating and cooling costs, improve comfort and durability, and support a healthier indoor environment.

• • Plumbing
    • Seek out plumbing penetrations throughout the home and seal around them with spray foam. Don’t forget to look in cabinets and utility closets
  • Ceiling
    • Look for obvious cracks and seams, and also dirty spots — these may indicate an air leak
  • Outdoor water faucets
    • Locate any penetrations through your exterior walls, and air seal around them with waterproof silicone
  • Exterior door frames
    • Apply caulk around the frame inside the home and apply weather strips to the door jambs. In these videos from Conservation Consultants Inc, learn about caulking around window and door frames and installing door sweeps.
  • Baseboards
    • Exterior wall travels up the wall and enters living spaces where plaster or drywall meet the floor. The task of sealing at baseboards is best accomplished with baseboards removed, then reinstalled. Alternatively seal using painter’s caulk at the top of the baseboard and/or use a backing rod to limit infiltration from below, if these areas are a noticeable problem.
  • Fireplaces
    • Fireplaces can be large openings to the outdoors and, even when in use, may lose more heat than they provide. Make sure the damper operates properly; if it does not, have it repaired or replaced. If the fireplace is no longer used, seal the chimney opening with one or two layers of rigid foam cut to fit and seal the edges with spray foam. Warning: always remove temporary chimney plugs before lighting a fire.

Hot-water pipes and water heaters

Why it matters. Water heating is the second-largest household energy use after space conditioning. Several low-cost steps can reduce waste without affecting comfort.

• • • Set the thermostat on your water heater to 120°F to get comfortable hot water for most uses.
    • Insulate hot and cold water pipes, as explained here.
    • Consider water conservation measures and installing heat pump water heater when the time comes to upgrade your appliance.

Choose projects based on your house—not a generic checklist

DIY improvements can provide meaningful benefits, but the best sequence depends on the home’s construction, existing insulation, air-leakage patterns, moisture conditions, mechanical systems, and the homeowner’s goals. E3 provides independent, contractor-neutral assessments and guidance to help you understand what matters most before investing in upgrades. Home Energy Assessments

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