Denver Energy-Efficient Window Installation by Precision Exteriors

New Installation vs. Window Replacement — Understanding the Difference

This distinction matters for project scope, cost, timeline, and permit requirements. Here is how to identify which applies to your project.

Window replacement involves removing an existing window unit from an existing rough opening and installing a new unit — same location, same or similar size. The wall structure is undisturbed. In most cases no building permit is required for standard replacement-in-kind in Denver Metro jurisdictions, and the project is completed in a day or less. This is the most common window project on existing Denver Metro homes.

New window installation involves one or more of the following: creating a new window opening in a wall that does not currently have one, enlarging an existing rough opening to accommodate a larger unit, converting a solid wall section to a window opening as part of a remodel, or adding windows in a home addition or accessory structure. Any of these requires structural framing work, which means permits, inspections, and a scope that goes beyond the window unit itself.

If you are unsure which category your project falls into, describe what you are starting from — an existing window location or a solid wall section — and we assess the scope during the estimate visit.

What New Window Installation Involves

Understanding the structural and construction scope of new installation helps set accurate expectations for cost, timeline, and disruption before any work begins.

Rough Opening Construction

Every window opening is framed by a rough opening — the structural frame of king studs, jack studs, sill plate, and header that carries the wall loads around the window void. When a new opening is cut in an existing wall, this framing must be built correctly to transfer load around the void without settling, racking, or transferring stress to the window unit itself. Incorrect rough opening framing — undersized headers, missing jack studs, sill plates not properly aligned — is the root cause of windows that bind, fail to latch, and develop frame gaps within a few years of installation.

Header sizing is the most consequential structural variable. The header carries the load of the wall assembly above the opening — wall framing, sheathing, potentially roof load depending on location — and must be engineered for the span. Wider windows require larger headers. Second-story installations and windows under roof loads require larger headers than first-floor installations in partition walls. We size headers correctly for the specific load condition, not to a generic rule of thumb.

House Wrap and Flashing Integration

The moisture management sequence around a new window opening — house wrap, pan flashing at the sill, head flashing above the window, and correct lapping of these elements with the wall assembly — is the most consequential quality variable in new installation. Errors in this sequence do not show up immediately. They show up as interior staining, wall cavity moisture damage, and frame rot two to five years after installation — long after the original installer has moved on.

The correct sequence: pan flashing installed at the rough opening sill before the window is set, so any water that gets past the window assembly drains out rather than into the wall; the window set and anchored in the opening; head flashing installed above the window and lapped over the top of the window frame; house wrap integrated with all flashing elements so that the drainage plane is continuous from the window outward. This sequence is not complicated but it must be completed in the correct order — it cannot be retrofitted after the window is set.

We integrate new window installations with the existing wall assembly's moisture management system and, where siding replacement is being done simultaneously, with the new siding installation sequence as well.

Air Sealing

The gap between the window frame and the rough opening framing — typically 1/4 to 1/2 inch on all sides — must be air-sealed after the window is shimmed and anchored. Low-expansion foam sealant applied to this gap from the interior eliminates air infiltration at the frame perimeter without creating pressure that bows the frame out of square. This is a step that is frequently skipped or done carelessly in low-quality installations and is one of the common sources of persistent drafts around new window installations.

Exterior Casing and Interior Trim

New window installations require exterior casing — the decorative and functional trim that transitions between the window frame and the exterior wall surface — and interior trim that finishes the rough opening on the inside. Both must be correctly integrated with the window frame, the wall cladding, and the moisture management assembly. Exterior casing is caulked to the window frame and to the wall surface with high-quality, paintable exterior sealant. Interior trim is installed after the window is confirmed square and operational.



Egress Window Installation

Egress window installation is one of the most common new installation projects on Denver Metro homes. Here is what it involves and why the code requirements exist.

What egress means. An egress window is a window large enough to allow a person to escape through it in an emergency — and large enough to allow a firefighter in gear to enter through it for rescue. The International Residential Code specifies minimum egress dimensions: minimum 5.7 square feet of net clear opening (5.0 sq ft for ground floor), minimum 24 inches net clear opening height, minimum 20 inches net clear opening width, and a maximum sill height of 44 inches from the finished floor. Colorado's adopted IRC follows these requirements.

Where egress is required. Every sleeping room must have at least one egress window or door. In finished basements, this applies to every room used as a sleeping space. Finished basement bedroom additions — a common project on Denver Metro homes converting unfinished basements — require egress window installation to meet code. This is not optional and not something that can be inspected around. Egress is a life-safety requirement.

What egress installation involves in Denver. Most Denver Metro homes built before 2000 with unfinished or partially finished basements have either no basement windows, or small hopper windows below grade that do not meet egress dimensions. Converting these spaces requires cutting through the foundation wall, installing a window well on the exterior, constructing a correctly sized rough opening in the foundation, and installing an egress-rated window unit. This is a specialized scope involving foundation cutting, concrete or masonry work, waterproofing at the window well, and drainage management at the well base. We assess the specific conditions at each project before quoting — foundation wall thickness, soil conditions, and existing drainage all affect the installation approach.

Permits are required. Egress window installations require building permits in all Denver Metro jurisdictions. We coordinate the permit process and the required inspections as part of the project scope.

Window Installation for Home Additions and Remodels

When windows are part of a larger home addition or remodel project, installation scope expands beyond individual openings. Common scenarios on Denver Metro homes include the following.

Room additions. New construction additions require windows sized and positioned for the room's function, light requirements, and egress compliance. Window placement affects structural framing — window locations must align with the framing plan and header schedule for the addition, not be added as an afterthought. We coordinate window placement with the addition's framing scope.

Basement finishing. Converting an unfinished basement to finished living space typically requires egress window installation for sleeping rooms, well window installation for light and ventilation in non-sleeping areas, and in some cases enlarging existing window openings to meet egress or ventilation requirements for the finished space use.

Garage conversions. Converting an attached garage to living space requires adding windows that meet ventilation, light, and egress requirements for the new use. Garage wall assemblies typically require reinforcement before window openings are cut — garage framing is often minimal and not designed to carry window header loads.

Sunrooms and enclosed porches. Adding glazed windows to an existing covered porch or converting a porch to a three or four-season sunroom involves significant window installation scope — multiple large openings, often with custom sizing or specialty glass, all requiring proper flashing and air sealing integration with the existing structure.

ENERGY STAR and HB 23-1161 on New Installation Projects

Colorado's HB 23-1161 requirement — ENERGY STAR certification for all replacement windows on residential structures three stories and under, effective January 2026 — applies to new installation projects as well as replacement-in-kind. Any window going into a residential structure at Denver Metro elevations must meet Northern climate zone ENERGY STAR U-factor and SHGC thresholds.

For new installation projects, the same altitude-specific considerations apply. IGUs specified and sealed at sea level arrive in Denver with pressure calibrated for lower-elevation conditions. At 5,280 feet, this pressure differential stresses edge seals over time. We specify altitude-appropriate products on every installation, whether replacement or new opening.

 Choosing the Right Window Type for New Installations

New installations give homeowners a choice that replacement-in-kind often does not — the window type and operating style can be selected for the specific location, use, and aesthetic rather than being constrained by what was there before. Here is a practical guide to the main window types for Denver Metro new installations.

Casement windows open outward on a side hinge, operated by a crank. They seal tightly against the frame when closed — the sash presses directly against weatherstripping on all four sides — which makes them among the most airtight operating window types available. They are excellent for locations where maximum ventilation and tight sealing are priorities: bedrooms, living areas, and any exposure benefitting from directional airflow. Casements are not the right choice for locations directly above exterior walking surfaces where an outward-swinging sash creates a hazard.

Double-hung windows open vertically with two sashes that slide past each other. They are the most common window type in Denver Metro residential construction and are appropriate for most wall locations. Modern double-hungs with tilt-in sashes allow cleaning from the interior, which matters on upper floors. Their weakness relative to casements is the sash-to-frame seal — the sliding sash cannot compress against weatherstripping the way a casement does, which makes them slightly less airtight at equivalent quality levels.

Picture windows are fixed-glass units that do not open. They provide maximum light transmission and are the most thermally efficient operating option because there is no operable sash to create air infiltration pathways. They are appropriate for locations where light is the priority and ventilation is provided by adjacent operable windows or mechanical systems. Picture windows do not meet egress requirements by definition.

Sliding windows open horizontally with one sash sliding past the other. They are practical for wide, low-profile openings — often used above kitchen counters or in basement applications. Like double-hungs, their sliding sash seal is less airtight than casement seals.

Awning windows are hinged at the top and open outward at the bottom. They can remain open during light rain without water intrusion, which makes them useful for basement applications and locations where ventilation during summer weather events is valued. They meet egress requirements only in larger sizes where the net clear opening meets the IRC thresholds.

For new installations, we discuss window type options during the estimate visit in the context of the specific location, use requirements, ventilation priorities, and egress needs before specifying the unit.

Window Installation FAQs

Does new window installation require a permit in Denver?

Yes — any project that involves cutting a new opening in an existing wall, modifying the rough opening size, or installing egress windows requires a building permit in Denver Metro jurisdictions. Standard replacement-in-kind — same size unit in an existing opening — typically does not require a permit. We confirm requirements for your specific project and municipality before work begins and handle permit coordination as part of the scope.

How much does new window installation cost in Denver?

New window installation — creating an opening in an existing wall — typically runs $800–$2,500 per window depending on wall construction, header requirements, window size, and finish work. Egress window installation in a basement, including foundation cutting, window well, and drainage, typically runs $2,500–$5,000 per opening. These are indicative ranges; actual cost depends on site-specific conditions confirmed during an estimate visit.

How long does new window installation take?

A single new window installation in an existing frame wall — standard residential construction — typically takes one full day including framing, window installation, flashing, and rough exterior casing. Egress window installation involving foundation cutting takes two to three days depending on foundation type and drainage conditions. Multi-window addition projects are scoped on a project basis.

Can I add a window to any exterior wall?

Most exterior walls can accommodate a new window opening with correct header sizing. Load-bearing walls require larger headers and more careful framing than non-load-bearing partition walls. Walls containing plumbing or mechanical runs require routing those systems before the opening is cut. We assess structural conditions during the estimate visit and identify any complications before quoting the project.

What is a rough opening and why does it matter?

The rough opening is the framed void in the wall structure that holds the window unit — the assembly of jack studs, king studs, header, and sill plate that carries wall loads around the window. A correctly sized and framed rough opening allows the window to be shimmed square, anchored correctly, and sealed properly. An undersized rough opening means the window cannot be installed correctly. An oversized rough opening leaves gaps that create air infiltration and require non-structural filler. Getting the rough opening right is the foundation of a window installation that performs correctly for 20 to 30 years.

Will new window installation disturb my interior walls or exterior siding?

Yes — that is the nature of the scope. Cutting a new opening requires removing interior wall finish material (drywall) around the opening, cutting through the wall framing, and removing exterior sheathing and siding at the new opening. Interior patching and exterior siding integration are part of the installation scope. We coordinate siding repair or replacement at new openings as part of the project, and we can scope combined siding and window installation when the siding is being replaced simultaneously.



Serving Denver Metro and Front Range Communities

Precision Exteriors Restoration provides window installation across the Denver Metro and Colorado's Front Range — Denver, Aurora, Lakewood, Arvada, Westminster, Thornton, Centennial, Littleton, Highlands Ranch, Castle Rock, Golden, Brighton, and Englewood. Colorado License #0248041. 999 18th St UNIT 3000, Denver, CO 80202. (720) 408-1840.

Related pages:

• Windows Hub → — overview of all window services
• Window Replacement → — replacement-in-kind for existing openings
• Window Repair → — repair options for existing windows
• Emergency Window Services → — 24-hour storm response
• Siding Services → — siding integration on new installation projects

Schedule Your Inspection

Call (720) 408-1840 or fill out the contact form for a free, no-obligation estimate on new window installation. We assess structural conditions, egress requirements, permit needs, and ENERGY STAR compliance requirements for your specific project.

Available 7 days a week. Emergency response available 24 hours.



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