Energy retrofits aren’t an a la carte affair. What gets done depends on how the house is currently performing, what the homeowner’s short- and long-term goals are, and which projects performed in which order will achieve those goals, all while doing no harm. That’s a tall order that is best begun with a full energy audit and a thorough discussion of long-range plans.

The elephant in the room is the budget. While the main benefits are improved health and comfort, anyone discussing energy retrofits needs to be prepared to answer questions about cost, level of effort, and ROI. These seven project summaries, though greatly oversimplified, are a first step toward keeping the conversation going.

Travel is not included in labor estimates.

Low-Flow

faucets & Fixtures

Install flow-restriction aerators and replace showerheads with low-flow models; replace toilets with low-flow (<1.6 gpf) models.

Materials cost: $1–$125 aerators/showerheads; $250–$500+ toilets

Labor: 15 mins. per aerator/showerhead/2–4 man hrs. per toilet

Estimated ROI: <1 yr.–5 yrs.

Obviously, ROI on a $1 aerator is almost immediate, but costlier fixtures pay back faster the more hot water the equipment saves. Conservation is the main concern, and making any of these changes will drastically reduce water consumption without sacrificing user experience.

Air-Sealing

Seal rim joists and all openings between floors. Seal around HVAC ducts, light fixtures, electrical devices, utility chases, soffits, entry doors, window weight pockets, fireplace flue dampers, and the attic access hatch. Test in/test out (blower door and combustion spillage).

Materials cost: $50–$6,000

Labor: 4–40 man hrs.

Estimated ROI: <1 yr.–8 yrs.

Air sealing and insulation are almost done together. Air sealing prevents the exchange of air between a home’s conditioned spaces, its unconditioned spaces, and the outdoors. This keeps contaminants and moist air from entering the home and controls air movement between floors. Air sealing greatly improves the comfort and health of occupants.

ERV / HRV

Install energy- or heat-recovery ventilator selected for compatibility with existing system and volume of home.

Materials cost: $600–$4,000

Labor: 4–36 man hrs.

Estimated ROI: n/a

This equipment consumes more energy than it saves, but it reduces the energy penalty for providing fresh air, which improves occupant health and safety. ERVs and HRVs solve different problems and differ greatly in price; choosing which to use depends on climate, home size, number of occupants, and other factors. Ductwork also affects cost. Ideally, ductwork supplies fresh air to living and sleeping areas and exhausts stale air from kitchen and baths. Note: An ERV or HRV doesn’t provide combustion make-up air.

Programmable Thermostat

Remove existing thermostat and replace with new digital model.

Materials cost: $50–$350

Labor: 1–3 man hrs.

Estimated ROI: <1 yr.–10 yrs.

In addition to climate and utility prices, many factors affect payback time, including type of HVAC system, how much home is occupied, number of occupants, and extent of air sealing and insulation. A simple 5-2 day thermostat is easiest for homeowners to use. More expensive units include Wi-Fi and more programming options, and “smart” units auto-adjust to use patterns. Add cost for slave units for multiple HVAC zones.

Smart Thermostats:

Insulation

Install insulation in attic spaces, crawlspaces, walls, and rim joists to complete thermal boundary. Use rigid foam, loose fill blown-in, and batt insulation as appropriate for the area being insulated.

Materials cost: $200–$10,000+

Labor: 4–100+ man hrs.

Estimated ROI: 5 yrs.–15 yrs.

Insulating is not cheap, but there are good long-term benefits, including much greater comfort. Exterior rigid foam is ideal but is costly unless siding is being replaced anyway. Adequate prep for subs (especially to provide access) is critical to quality. Blower door test-out should be done before drywall is applied. Rim and attic are most important, as are window weight pockets, which can be time-consuming.

Tankless water heater

Remove existing storage-type water heater and replace with gas-fired tankless water heater.

Materials cost: $1,500–$3,500

Labor: 4–8 man hrs.

Estimated ROI: 5 yrs.–15 yrs.

With low-flow fixtures, size the heater to achieve the desired temperature rise at the lower flow rate. Aim for simultaneous use of shower, dishwasher, and washing machine with no heat loss. The stainless-steel vents required for many units can be costly. When a home needs a new boiler and a new water heater, high-efficiency combination units are a good choice.

On-Demand circulating pump

Mount pump, run water supply lines, install activation switch or occupancy sensor. Does not include cost of opening, closing, and refinishing walls and floors.

Materials cost: $50–$150

Labor: 4–8 man hrs.

Estimated ROI: 1 yr.–2 yrs.+

Although it contributes to water conservation, this is mainly a convenience item. It is cheap and easy when walls and floors are open; when they’re not, it can cost five to 10 times as much to install. Circulating pump systems should be demand-based — constant recirculation actually costs more in energy. Use an occupancy sensor or manual switch to start the pump.