An exterior door does more than let people inside. It shapes the first impression of a home, holds back wind and rain, and separates conditioned indoor air from the outdoors. Patio, porch, and garage entrances each need a different configuration, and the material you choose affects energy bills, maintenance time, and security. Before comparing brands, start with the basics: where the door sits, how often it opens, and what climate it faces. Builders sort through door types for timber homes and other structures by matching the entryway to exposure and traffic, and the same logic applies to a replacement project.
What to Consider Before You Buy
Experienced residential contractors put location first: where the door is going determines the right one to use. A south-facing front door bakes in afternoon sun and needs UV-stable materials. A door on the prevailing-wind side of the house takes the brunt of rain and needs a solid threshold and weatherstripping. A garage man-door gets slammed daily, while a formal entry opens a few times a week. Answer those questions before you shop, then compare weatherproofing and hardware details such as hinges, locksets, and thresholds.
Check local rules before ordering. Some homeowners associations restrict door colors and styles, and building codes set requirements for egress width, fire rating, and accessibility on certain openings. A quick call to the building department saves a costly return.
Key Questions to Ask Yourself
- Which entrance is this? Front entry, patio, porch, garage, or side yard.
- How much sun and rain does the wall face?
- How often does the door get used each day?
- Do you want a solid slab, glass panels, or a mix?
- What is the rough opening size, in width and height?
Measure the Rough Opening
Getting the Numbers Right
Measure the width and height of the opening at three points, top, middle, and bottom, and use the smallest reading. Check whether the opening is square with a level and a framing square. Prehung units hide small framing errors, but a slab door needs a nearly perfect opening. Write the measurements down before you visit a supplier.
Exterior Door Materials Compared
Three materials dominate exterior door sales: steel, fiberglass, and wood, with aluminum common on patio and commercial applications. Each changes the price, the insulation value, and the maintenance schedule. The decision between interior and exterior door types starts with the same question: how much abuse will this door take?
| Material | Durability | Insulation | Maintenance | Relative Cost |
|---|---|---|---|---|
| Steel | High, dents on hard impact | Good with foam core | Touch up scratches to prevent rust | Lowest |
| Fiberglass | Very high, resists dents | Excellent with foam core | Very low, paint to refresh | Mid |
| Wood | Moderate, needs protection | Good, depends on core | Repaint or refinish every few years | Highest |
| Aluminum | High, good for wide spans | Lower, thermal break needed | Low | Mid |
Steel: Strength at a Lower Price
Steel doors offer the best security per dollar and accept most hardware upgrades. A foam core raises the R-value, and modern embossed skins imitate wood grain. Scratches through the paint layer can rust, so touch-up paint belongs in the maintenance kit. Basic steel units typically start in the low hundreds of dollars, which makes them the budget leader for front entries.
Fiberglass: The Low-Maintenance Middle Ground
Fiberglass resists dents, warping, and rust, and it insulates well when paired with a foam core. It takes paint cleanly, so homeowners can change the color without replacing the door. The main drawbacks are a higher price than steel and a surface that needs the right primer for good paint adhesion.
Wood: Classic Look, Ongoing Care
Wood offers the richest grain and the most traditional look, and it can be stained to match interior trim. It also demands the most attention: exterior-grade paint or stain, periodic recoating, and prompt repair of any cracked finish. Mahogany, oak, and fir are common choices, with the species affecting both price and durability.
Replacement cycles differ sharply between materials. A well-maintained steel door can last 30 years or more, and fiberglass performs in the same range, while a wood door often needs replacement sooner if refinishing is skipped. Add the cost of repainting every few years to the wood door total before you compare budgets, because the cheapest door at the register is not always the cheapest over two decades.
Door Styles and Configurations
Beyond material, the door style sets the look. Single doors are the default for front entries. Double doors widen the opening for moving furniture and make a statement. French doors pair glass panels and suit patios. Sliding glass doors maximize light and deck access, and barn-style sliders are a newer option for interior and covered exterior openings. Choose the swing direction so the door opens against an interior wall rather than into a walkway.
Match the entry style to the rest of the facade so the house reads as one design. A farmhouse door looks out of place against sleek siding, and a modern full-lite door can overwhelm a cottage. Coordinate with exterior cladding such as beveled wood siding, and repeat the door’s color or material in the trim, shutters, and porch posts.
Picking the Right Style for Each Entrance
- Front entry: single or double, with sidelites for extra light.
- Patio: sliding, French, or multi-slide doors.
- Garage man-door: solid steel or fiberglass for security.
- Side and porch doors: simpler styles that match the main entry.
Glass and Privacy Trade-Offs
Full-lite doors flood the entry with light but put the interior on display. Frosted, patterned, or low-E glass keeps light while adding privacy. If the door faces a busy street, choose obscure glass or add a curtain treatment.
Energy Efficiency and Weatherproofing
An exterior door is a hole in the building envelope, and its insulation and seals decide how much heat escapes. Look for foam-core construction, weatherstripping that compresses evenly around the frame, and a threshold with a tight sweep. ENERGY STAR-rated doors meet tested U-factor and air-leakage criteria, and the label matters most in extreme climates. For wood doors, correct exterior door finishing protects the edges, top, and bottom from the moisture that causes swelling and rot.
Reading the Numbers: R-Value and U-Factor
R-value measures resistance to heat flow, and higher numbers insulate better. U-factor measures heat transfer rate, and lower numbers perform better. A steel door with a polyurethane foam core typically lands around R-5 to R-7, while an uninsulated hollow door sits closer to R-2. Compare U-factor, not marketing claims, when you shop.
Weatherstripping and Thresholds
Replace worn weatherstripping before buying a new door, because a tight seal is often the cheapest energy upgrade in the house. Check the threshold sweep for gaps and make sure the door compresses the gasket evenly when closed. The dollar bill test works: close the door on a bill, pull it out, and it should meet resistance.
Air leakage around an average exterior door accounts for a measurable share of a home’s total infiltration. Tight weatherstripping plus a threshold sweep trims that loss, which is why the seal matters as much as the panel. Install the door so the gasket compresses evenly around all four sides and the sweep drags slightly on the threshold when closed.
Installation: Prehung or Slab
Doors arrive in two forms. A prehung unit comes with the slab attached to a factory-built frame, which keeps the jambs square and speeds installation. A slab is just the door panel, and it demands precise fitting, mortising, and shimming. Most homeowners choose prehung units for exterior work because the factory alignment prevents the binding and air leaks that plague slab installations. A professional prehung exterior door installation includes proper flashing, shimming, and sealing, which matter more than the door itself for long-term performance.
When to Call a Professional
- The rough opening is out of square by more than 1/4 inch.
- Water damage or rot extends into the framing.
- The floor slopes and the threshold needs custom scribing.
- You are replacing a door in a masonry or stucco wall.
Cost, Shopping, and the Final Check
Prices vary widely by material and configuration. A basic steel entry door typically starts in the low hundreds of dollars, fiberglass models climb into the mid-range, and wood or custom units cost the most before installation labor. Big-box stores offer convenience and frequent sales, lumberyards stock better-grade options and can special-order sizes, and specialty door shops carry premium lines. Compare warranties, not just sticker prices, and confirm the door meets local building codes for egress and fire safety. Builders who track material performance benchmarks across products consistently find that frame quality and hardware grade separate a 10-year door from a 30-year door.
Installation labor often rivals the door price. A prehung exterior unit typically takes a crew a few hours, while a slab retrofit can stretch across a full day with fitting, mortising, and shimming. Get a written quote that includes disposal of the old door and any framing repairs that show up once the old unit comes out.
A Pre-Purchase Checklist
- Confirm the rough opening size and swing direction.
- Choose material by exposure, budget, and maintenance tolerance.
- Compare U-factor and check for ENERGY STAR labeling.
- Pick hardware grade and finish before ordering.
- Schedule delivery so the door is stored indoors until install day.