While they are called patio doors, they are designed to provide access to the outside living areas of a home, not just a patio. The doors may open to the deck or lawn of the home, a pool or spa area and are most frequently glass systems that offer a clear view to the outdoors.

Building Codes of the area will have an impact on the patio door. Always check with the building department when choosing a door or window.

Activities and lifestyle may be a factor when making a decision on the door. The amount of space inside and outside of the door opening is important, especially if choosing a hinged door instead of a sliding door.  If a large opening is desired, a multi-slide or bi-fold option may be appropriate. Water infiltration could be a problem if a spa or pool is located close to the door.

Energy-efficiency of the door can save money in the long run. Since patio doors are mostly glass, consider the type of glass to be used. The R-value reports the energy-efficiency of the glass; the higher the number the more efficient. The U-factor is the energy-efficiency of the whole door, including the frame and the lower the number the more efficient.

If security is a consideration, choose a multi-point locking system to deter intruders.

Privacy may be a concern. Since patio doors contain large glass areas, blinds between the glass, or privacy glass, may be an option.

Sound transference can be decreased by choosing glass options that offer a noise reduction. 

The architectural style of the home may have an impact on the patio door style. Depending upon the visual impact of the door on curb appeal, the patio door may demand grills, or wood to maintain the value of the home.

Sliding doors open along a top and bottom rail. One of the doors will be stationary while the second door will slide open.  Opens either right hand or left hand.

Swing (French) doors are hinged and will swing in or swing out. In regular swing doors, one of the doors may be stationary with a left hand or right hand swing. French doors open at the center and swing out, providing a larger opening but requiring more space outside to accommodate the size of the doors.

Bi-fold doors are multi-unit doors that travel along a track to expand the opening to the outside. Bi-folds operate accordion-style and fold outside or inside, depending upon the space provided and the need of the homeowner.

Multi-slide doors open for an unobstructed view. Full door panels will remain stationary until lifted into the sliding track and stacked or fitted into a wall pocket.

Glass makes up the largest portion of a patio door.

To reduce solar heat gain and block ultra-violet rays use Low -E glass. The sun’s rays provide increased heat and light that may fade materials. By including Low-E glass in the window system, heat and cold outside are reflected back into the environment and heat and cold inside are reflected back into the structure.

Impact-resistant glass will be required in some areas along the coastlines and storm-prone areas. Know the Building Codes for the area in which the home is located.

Double and triple pane glass provide insulation and noise attenuation.

Grills can be added to the patio door, and will enhance a French door due to styling. The grills mimic divided lites for architectural accuracy. Depending upon the manufacturer, grills may be placed on the inside glass panel or between the panes of glass.

Shades and Blinds may be installed between the panes of glass for privacy and to block outside sunlight.

Screens are available in a variety of designs, depending upon the design of the door and manufacturer. Sliding screens, side retractable screens and top-hung rolling screens block intrusion from for bugs and even sunlight.

Wood: The traditional material for frames, wood provides a thermally efficient frame that is durable. Using wood construction offers the ability to change colors and when well maintained, a long life for the unit. Available in a variety of species, the homeowners can match the wood to the trim of the home or complement the outdoors.

Wood Clad: The frame is constructed of wood with a metal or vinyl cladding on the exterior to protect the unit from weather conditions. The interior part of the door frame retains the wood for purposes of aesthetics. Cladding requires less maintenance and is available in an array of colors.

Vinyl: Polyvinyl chloride is extruded into frames that are constructed with hollow spaces to slow temperature transfer for energy efficiency. Low maintenance, vinyl is available in an array of colors for aesthetic purposes. Colors are integral to the vinyl so scratching the exterior will not show as the color is throughout the material.

Steel: While metal will conduct heat/cooling more quickly than other materials, thermal breaking in the construction of steel patio door frames can make them as energy efficient as other materials.

Fiberglass and composites: Fiberglass frames are strong, making them useful for large door panels, and are energy efficient. “Pultruded with or without resins and about 60 percent or more glass, they are considered “green.”  Frames can look like wood with graining or smooth surfaced, and can be painted.

Size of the opening is a great impact on the cost of the patio door.  Taller and wider doors will cost more than a standard size patio door due to the materials needed to construct the unit. Custom sizes will have a major impact on the budget.

The material used for the frame is a major consideration. Wood doors, especially hardwoods such as Mahogany, are more expensive than other materials. Steel is the least expensive, followed by vinyl and fiberglass increasing the cost.

Glass that is Low-E or double and triple pane will increase the cost. Impact-resistant glass also costs more since additional film applied to an internal pane is one of the means of blocking storm-driven debris from entering the home.

The type of patio door is another major factor, with sliding doors the least expensive, hinged doors increasing the cost. Bi-fold patio doors and multi-slide doors cost the most as these will be larger, more complicated to construct and install.

Installation by a professional will increase the cost but the more complicated systems may require the employment of an expert to fulfill warranties.