Front door installation when the opening is new

What is front door installation?

Front door installation in the first-install sense means building or finishing a weather-tight rough opening, pan-flashing the sill, setting a pre-hung entry unit plumb and square, and tying the door into the wall’s water-resistive barrier so bulk water never reaches the framing. That is the job on new construction, additions and newly cut openings. If you already have a front door and are swapping it, the decisions are different - start with entry door replacement instead.

Signs you need front door installation

• You are building new, adding a foyer, or converting a wall into an entry where no door exists yet
• An addition needs an exterior door and the opening will be framed as part of the project
• You are cutting a new opening in an existing wall and need structure, header and weather barrier handled together
• A builder or remodeler is sequencing housewrap, windows and doors and the entry has to land in that order
• You were handed a pre-hung unit and a rough opening size, not an existing door to measure against
• Insurance or a remodel created a new primary entrance that never had a door slab before

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How front door installation actually works

1. 1

   Confirm this is a first install, not a replacement

   If jambs, sill and exterior trim already exist and you are changing the unit, you are in replacement territory - insert versus full-frame, slab versus pre-hung into existing conditions. This page assumes the opening is new or fully rebuilt.

   Watch forBig-box “installation” booked as a product add-on when your opening is rotten. That programme is not a rebuild crew. See entry door replacement for retrofit triage.

2. 2

   Rough opening, header and structure

   The opening must be sized to the unit’s requirements with correct header support over the span. On load-bearing walls this is carpentry and sometimes engineering, not trim work. Dimensions are checked before the door is ordered when possible.

   Watch forOrdering a door from a showroom photo before the rough opening is measured and framed. Pre-hung units are unforgiving of “we will make it fit.”

3. 3

   Sill pan and flexible flashing - before the unit goes in

   A pan that drains outward, properly integrated flashing legs, and continuity with the water-resistive barrier are what keep the subfloor and framing dry for decades. This is the step sales demos skip and leak callbacks always find.

   Watch forA unit set on bare sill plate with a bead of caulk as the plan. That is not a pan. Ask what product and sequence are used at the sill.

4. 4

   Setting the pre-hung unit plumb, level and square

   Shims at hinge and strike locations, consistent margins, and a sill that supports without twisting the frame. The door must operate without binding before exterior trim hides the shims.

   Watch forForcing the jamb to a bowed opening instead of correcting the framing. The door will tell on you every season as humidity moves the wall.

5. 5

   Air seal, insulation at the gap, exterior and interior finishes

   Low-expansion foam or appropriate backer and sealant at the gap, then cladding-compatible exterior trim and interior casing. Hardware, closer and thresholds are adjusted last so weatherseals actually touch.

   Watch forHigh-expansion foam that bows jambs. Use products rated for doors and windows, applied with restraint.

What does front door installation cost?

First-time front door installation is priced as carpentry plus the unit: opening, flashing, set and finishes. Cutting a new opening in an existing wall costs more than setting into a framed new-construction opening. Unit price is only one line; structure and weather barrier work often dominate.

See the full front door installation cost guide - by material, size and region →

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