The concept of home improvement, home renovation, or remodeling is the process of renovating or making additions to one's home. Home improvement can consist of projects that upgrade an existing home interior (such as electrical and plumbing), exterior (masonry, concrete, siding, roofing) or other improvements to the property (i.e. garden work or garage maintenance/additions). Home improvement projects can be carried out for a number of different reasons; personal preference and comfort, maintenance or repair work, making a home bigger by adding rooms/spaces, as a means of saving energy, or to improve safety. Types of home improvement While "home improvement" often refers to building projects that alter the structure of an existing home, it can also include improvements to lawns, gardens, and outdoor structures, such as gazebos and garages. It also encompasses maintenance, repair, and general servicing tasks. Home improvement projects generally have one or more of the following goals: Comfort Upgrading heating, ventilation and air conditioning systems (HVAC). Upgrading rooms with luxuries, such as adding gourmet features to a kitchen or a hot tub spa to a bathroom. Increasing the capacity of plumbing and electrical systems. Waterproofing basements. Soundproofing rooms, especially bedrooms and baths. Maintenance and repair Maintenance projects can include: Roof tear-off and replacement. Replacement or new construction windows. Concrete and masonry repairs to the foundation and chimney. Repainting rooms, walls or fences Repairing plumbing and electrical systems Wall papers Furniture polish High-end expertise in quality home interior and exterior works Shower maintenance Additional space Additional living space may be added by: Turning marginal areas into livable spaces such as turning basements into recrooms, home theaters, or home offices – or attics into spare bedrooms. Extending one's house with rooms added to the side of one's home or, sometimes, extra levels to the original roof. Such a new unit of construction is called an "add-on". Saving energy Homeowners may reduce utility costs with: Energy-efficient thermal insulation, replacement windows, and lighting. Renewable energy with biomass pellet stoves, wood-burning stoves, solar panels, wind turbines, programmable thermostats, and geothermal exchange heat pumps (see autonomous building). Safety and preparedness Emergency preparedness safety measures such as: Home fire and burglar alarm systems. Fire sprinkler systems to protect homes from fires. Security doors, windows, and shutters. Storm cellars as protection from tornadoes and hurricanes. Bomb shelters especially during the 1950s as protection from nuclear war. Backup generators for providing power during power outages. Home improvement