Job Type |
Action |
Impact |
Siding replacement |
Comprehensive flashing and drainage plane system
Rigid insulation with vapor permeability greater than 1 installed over sheathing
Vented rain screen for wood siding
Blown insulation in wall cavities
Window and door replacement
Vented rain screen and flashing/drainage plane prevents bulk moisture from getting into wall assembly.
Insulation and window replacement allows for downsizing of the heating and cooling system when replaced.
Rigid insulation improves the moisture tolerance of the wall assembly.
Storm windows/ screens |
Use solar shade screen.
Hard-coat low-E glass on storms
Reduces heat gain through windows, lowering air-conditioning loads and system size at time of replacement.
Window and door replacement |
Integrate flashing with wall drainage plane.
Siding replacement
High-performance glazing (U-value 0.35 or less, solar heat gain coefficient 0.35 or less)
Integrated flashing prevents bulk moisture from getting into wall assembly.
High-performance glazing allows for downsizing of the heating and cooling system when replaced.
Roof replacement |
Install overhangs and gutter system.
Choose light-colored shingles.
Install roof rafter/truss tie-down anchors.
If ducts are located in attic space, create a "cathedralized" attic. The cathedralized attic should have rigid insulation and sheathing over existing sheathing, and blown or batt insulation in between framing members at underside of roof sheathing. Do not ventilate cathedralized attics. Or:
Seal ducts in attic using mastic and bury in blown insulation.
Install radiant barrier.
Overhangs and gutter systems divert water from the building, helping prevent bulk moisture from getting into the structural assemblies.
Light shingles reduce cooling load.
Adding attic ventilation can minimize moisture buildup in attic but only if no ducts in the attics are leaking air.
Sealing ducts provides more conditioned air to spaces that need it and can lower air-conditioning size at time of replacement.
Radiant barrier lowers attic temperature, reducing heat gain through ceiling and lowering air-conditioning loads.
Thermal insulation (general) |
Roof replacement/repair
Comprehensive drainage plane and flashing system
Overhangs and gutter installation
Air-sealing building envelope
Siding replacement
Installation of dehumidification system
Insulation must be kept dry to be effective. Any moisture intrusion into insulated cavities will degrade the insulation performance. It also can lead to structural deterioration and provide an environment for the growth of mold and mildew. Installing overhangs and gutters helps keep water away from walls and foundation systems.
Air-sealing the building envelope limits the amount of moist air that moves through assemblies, reducing potential moisture problems. In addition, air sealing improves energy efficiency and comfort for the occupants. Air sealing must be coordinated with combustion air needs and pressure balancing of the HVAC system. Occupants might want to consider installing controlled mechanical ventilation as part of the air-sealing package.
Insulating the building envelope lowers the run time of existing air-conditioning systems, reducing the amount of moisture being extracted from the air inside the house.
Thermal insulation (wall cavity) |
Wall drainage plane and flashing
Siding replacement
Comprehensive drainage plane and flashing systems also can be installed during a siding replacement project.
If done in conjunction with siding replacement, a system of cavity insulation and vapor-permeable rigid insulating sheathing can be used to improve the moisture tolerance of the wall assembly.
Thermal insulation (roof) |
Roof replacement/repair
Add attic ventilation if no ducts are in attic space.
If ducts are located in attic space, create a "cathedralized" attic. The cathedralized attic should have rigid insulation and sheathing over existing sheathing, and blown or batt insulation in between framing members at underside of roof sheathing. Do not ventilate cathedralized attics. Or:
Seal ducts in attic using mastic and bury in blown insulation.
Install radiant barrier.
Adding attic ventilation can help minimize moisture buildup in attic but only if no ducts in the attics are leaking air.
Sealing ducts provides more conditioned air to spaces that need it and can lower air-conditioning size at time of replacement.
Radiant barrier lowers attic temperature, reducing heat gain through ceiling and lowering air-conditioning loads.
Thermal insulation (floors) |
Not generally recommended over crawl spaces or basements except in flood-prone areas
Air-seal floor system.
Cantilever floors over ambient conditions should be air-sealed to improve comfort and insulation effectiveness.
Insulation and air sealing can yield downsizing of heating and cooling equipment.
Thermal insulation (crawl space/ basement walls) |
Implement complete bulk-water management system (roof, siding, gutters, drainage).
Install continuous and sealed poly ground cover over slab/earth floor of crawl space/basement.
Seal crawl-space vents.
Sealed ductwork
Air-seal band joists at floor system.
Provide supply and return air to basement or crawl space.
Significant water intrusion can come into houses through groundwater or surface water that is not drained away from the building. This can cause elevated moisture levels in crawl spaces and basements, leading to structural rot and mold and mildew growth.
A continuous polyethylene ground cover prevents the diffusion of moisture out of the ground. By insulating and conditioning crawl spaces and basements, the air is tempered, and relative humidity is controlled. Basement insulation should be semi-vapor-permeable to allow for drying to the inside, and access strips might be necessary to provide for insect inspections.
Sealing ductwork ensures airflow to the spaces where it is needed and might enable the downsizing of air-conditioning equipment during replacement.
Air-sealing band joists limits the introduction of warm, humid air.
Furnace and air-conditioning equipment replacement |
Air sealing
Duct sealing
Integrate dehumidification.
Controlled mechanical ventilation
Solar shade screens
Thermal insulation package
Window replacement
Adding insulation and air-sealing the house lowers the heating and cooling load, and if a heat pump with resistance backup heat is being installed, less resistance heat is needed, and the pump will operate less often.
Sealing ducts ensures that air is distributed to spaces where it is needed, and if the sealing reduces the duct leakage outside the conditioned envelope, the heating and air-conditioning equipment can be downsized.
Dehumidification system integration (either through two-speed equipment or separate dehumidifier) can help maintain comfort conditions without the use of cooling system.
Low-cost whole-house supply ventilation can be introduced as a low-cost addition at time of system replacement.
Installing shade screens or high-performance replacement windows can reduce the size of the air conditioner.
A major load on the air-conditioning system is from windows.
Kitchens and baths |
The one thing consistent across all kitchen and bath remodels is the need to ensure adequate ventilation to take care of moisture and indoor air quality issues. But be careful: High-capacity kitchen exhaust fans draw pollutants and water vapor out of the kitchen, but they also can depressurize areas of the home and increase the chance for back-drafting of naturally vented combustion appliances. If you let air out, you have to suck fresh air back in.
If adding window area, recalculate the heating and cooling load and address equipment accordingly.
Energy- and water-efficient appliances, such as Energy Star-labeled models
The right-sized HVAC equipment increases efficiency and homeowner comfort.
Additions |
The one thing consistent across all kitchen and bath remodels is the need to ensure adequate ventilation to take care of moisture and indoor air quality issues. But be careful: High-capacity kitchen exhaust fans draw pollutants and water vapor out of the kitchen, but they also can depressurize areas of the home and increase the chance for back-drafting of naturally vented combustion appliances. If you let air out, you have to suck fresh air back in.
If adding window area, recalculate the heating and cooling load and address equipment accordingly.
Energy- and water-efficient appliances, such as Energy Star-labeled models
Significant water intrusion can come into houses through groundwater or surface water that is not drained away from the building. This can cause elevated moisture levels in crawl spaces and basements, leading to structural rot and mold and mildew growth.
A continuous polyethylene ground cover prevents the diffusion of moisture out of the ground. By insulating and conditioning crawl spaces and basements, the air is tempered, and relative humidity is controlled. Basement insulation should be semi-vapor-permeable to allow for drying to the inside, and access strips might be necessary to provide for insect inspections.
Sealing ductwork ensures airflow to the spaces where it is needed and might enable the downsizing of air-conditioning equipment during replacement.
Air-sealing band joists limits the introduction of warm, humid air.
Air sealing and insulating throughout the home might enable you to upgrade to high-efficiency, smaller HVAC equipment, increasing comfort and efficiency without radically increasing cost.