GS Exterior Experts replaces entry doors, sliding glass doors, hinged patio doors and other exterior door systems for Colorado homeowners.
We evaluate the entire opening — including the frame, sill, threshold, flashing, air sealing, trim and surrounding exterior — so the new door is properly integrated with the home.
Our team can also coordinate windows, siding, exterior trim, decks and more involved opening changes when the project requires them.
Over 25 years on Front Range homes
Entry · Patio · Sliding · Hinged
ProVia · Marvin · Pella · Simonton
Door + threshold + flashing +
exterior integration
Serving Littleton and the surrounding South Metro communities.
Start Here
Most door projects start with one of these six situations. Pick the closest one and we will take it from there.
01
Improve curb appeal, fit and exterior integration.
02
Replace an aging, difficult or poorly performing sliding system.
03
Create a more traditional swinging connection to a patio or deck.
04
Explore multi-slide, bi-fold or larger configurations where available.
05
Create new outdoor access from an existing wall opening.
06
Compare the available options with GS before
committing to a direction.
The GS difference
A door performs as part of an opening, threshold and wall assembly — not as a standalone slab. The frame, sill, threshold, flashing, air sealing, trim and surrounding wall all affect how the finished installation operates, seals, drains, looks and integrates with the home.
Anatomy of a complete door opening
Door unit — slab, panels or sliding system
Frame and jambs
Threshold and sill
Rough opening and framing
Flashing and drainage path
Air sealing and insulation
Weather-resistive barrier integration
Exterior trim and siding return
Interior finish and flooring transition
Deck, patio or landing interface
Because GS also works on siding, trim, windows and decks, we can evaluate and correct the conditions around the door instead of working around them.
Door types
Different door types solve different problems. Here is how the main categories compare — and where each one usually makes sense.
A new entry door should coordinate curb appeal, operation, weather protection, glass, hardware, siding and trim — not just the slab itself.
Patio doors affect natural light, traffic flow, furniture placement and how the home connects to outdoor living spaces.
Panel count, rollers, tracks and glass all affect how a sliding door operates years after installation.
Swing direction, clearance and hardware need to be planned against furniture, decks and landings.
Converting a window into a door is a structural project, not a swap. Depending on the wall, it may involve evaluation, framing, a new header, permits, exterior and interior finish work, siding, weatherproofing and a deck, landing or stairs.
Narrow it down
Consider
Entry / front door
Sliding glass door
French / hinged door
Sliding / multi-slide
Multi-slide / bi-fold, where available
Window-to-door conversion
The lineup
Door manufacturers are not interchangeable. Each one plays a different role depending on whether you are replacing an entry door, an aging slider or planning a larger architectural opening.
ProVia is often the most relevant option for homeowners comparing entry systems — fiberglass and steel construction, decorative glass, sidelites, transoms and coordinated storm or patio systems.
Well suited to expansive glass and sophisticated indoor/outdoor connections, and to coordinating doors with a Marvin window package.
A practical direction when a homeowner wants entry
and patio options from one manufacturer, especially
alongside existing Pella windows.
A straightforward sliding patio-door replacement
option, and a common fit for value-focused window +
patio-door packages.
Manufacturer roles are not interchangeable. Only the products GS actually sells should be published here.
Strong role
Common door categories
Entry-door anchor and replacement systems
Entry, patio, hinged, storm
Premium architectural and large-opening systems
Sliding, swinging, multi-slide, bi-fold
Broad entry + patio selection
Entry, sliding, hinged, large-opening
Value-oriented patio replacement
Sliding / patio
Design options
Configuration, glass, hardware and finishes are decided together — the exterior colors have to work with the siding and trim, and the interior side has to work with the trim and flooring you already have.
Single, double, sliding, hinged or multi-panel — and which way it should operate.
Clear, privacy or decorative glass, grid patterns and how much glazed area you want.
Surrounding units change both the light inside and the proportions of the elevation.
Handles, locking hardware and finish — the part you touch every day.
Frame color, door color, trim profile and how it coordinates with the siding.
Trim, wall finish and the flooring transition at the threshold.
Colorado conditions
Front Range doors deal with intense sun, wind-driven snow, wide temperature swings and very different exposure from one elevation to the next. That changes what we recommend for the same house, wall by wall.
Weather exposure
Wind, snow, sunlight, directional exposure and temperature change.
Glass performance
U-factor, SHGC and glazing configuration where relevant to the product.
Air sealing
The door and frame need to seal as a complete assembly, not just at the slab.
Water management
Threshold, sill, flashing and drainage decide what happens to water that gets there.
Exact configuration matters
ENERGY STAR eligibility and NFRC ratings depend on the actual product configuration — not on the manufacturer name.
Assessment
Not every door issue requires the same solution. We evaluate the slab, frame, threshold and surrounding opening before defining the project.
◆ Drafts around the frame
◆ Door rubbing or sticking
◆ Damaged threshold
◆ Failed glass seals
◆ Warped or deteriorated components
◆ Poor connection to the patio or deck
◆ Difficult operation
◆ Visible frame deterioration
◆ Water around the sill
◆ Unreliable locking
◆ Outdated appearance
◆ A desire for more natural light
Scope of work
Two different scopes of work. The condition of the existing frame, threshold and wall usually
decides which one is appropriate — and we determine that before the product is ordered.
Framing retained
A standard replacement into the existing opening, with the surrounding framing and exterior largely left in place.
Appropriate where
› Dimensions remain similar
› Framing is sound
› Threshold conditions are acceptable
› No structural modification is required
Rebuilt to the rough opening
A more involved replacement where the opening itself is opened up, inspected, corrected and reintegrated with the exterior.
May be required where
› Threshold deterioration or water intrusion exists
› Frame condition is poor
› Door size or configuration changes
› Sidelites or transoms change
› Siding integration or framing changes are involved
Permits:
requirements vary by jurisdiction and project scope. Structural changes to an opening commonly require additional review and may require permits or engineering.
One exterior contractor
GS can coordinate windows, doors, siding, trim, exterior finishes, decks and landings as one sequence instead of three separate projects.
Coordinate style, frame colors and installation sequencing so the elevation reads as one decision.
With siding off, there is far better access to flashing, weather-resistive barrier and trim integration around the opening.
Coordinate opening location, threshold transition and landing or deck access with how you actually use the space.
Window-to-door conversions
Converting an existing window opening into a door is more involved than a standard replacement. Not every window can become a door — a feasibility visit is how we find out.
Permit requirements vary by jurisdiction and project scope. Structural changes to an opening commonly require additional review and may require permits or engineering, so we confirm the path before any product is ordered.
What to expect
Understand your goals, the existing opening and the surrounding exterior.
Compare suitable configurations and manufacturers side by side.
Verify the opening before anything is ordered.
Define product, frame, threshold, trim and related work in writing.
Order the exact approved configuration.
Remove existing components and inspect the conditions underneath.
Set, flash, seal and integrate the new system with the wall assembly.
Complete exterior and agreed interior finish work.
Review operation, locks, hardware and applicable warranty information.
Recent work
Entry and patio door projects on real Colorado homes, with the product and scope
details that shaped them.
Entry door project
Detail
Detail
Detail
Detail
Detail
Homeowner goal, related exterior work and unique challenge to be written from real project notes.
Patio door project
Detail
Detail
Detail
Detail
Detail
Homeowner goal, related exterior work and unique challenge to be written from real project notes.
Conversion project
Detail
Detail
Detail
Detail
Detail
Homeowner goal, related exterior work and unique challenge to be written from real project notes.
The clearest demonstration of complete-opening work is the middle photo — the sill, flashing and WRB nobody sees once the trim goes on.
What Homeowners Say About Their Door Projects
Homeowner quote pending — should reference fit, operation, curb appeal, trim and communication on a real entry-door project.
Homeowner quote pending — should reference fit, operation, curb appeal, trim and communication on a real entry-door project.
Homeowner quote pending — should reference fit, operation, curb appeal, trim and communication on a real entry-door project.
Two projects with the same door can price very differently once the opening is opened up. These are the factors that actually move the number.
Financing
Financing options may be available for qualified homeowners — most
relevant on whole-home exterior projects, door + window packages, larger patio-door systems and window-to-door conversions. Explore financing
› Straightforward replacement
› Standard configuration
› Limited opening modifications
› Upgraded material or glass
› More design options
› Additional trim or threshold work
› Large opening
› Architectural system
› Custom finishes
› Structural and exterior coordination
These tiers describe scope, not quotes. Actual pricing comes from the measured opening and the approved product configuration.
The difference
We evaluate the frame, threshold, flashing and surrounding exterior — not just the door slab.
Compare appropriate products from the manufacturers GS actually offers, rather than one predetermined line.
Doors coordinated with siding, trim and windows, so the details around the opening are resolved once.
Opening modifications and related exterior scope handled in-project when they are required.
Exposure, glass configuration and performance considered based on the actual project and elevation.
Know what product, installation and finish work are included before the project begins.
Service area
GS Exterior Experts is based in Littleton and serves homeowners throughout Denver Metro and
surrounding Front Range communities.
Littleton
Englewood
Centennial
Highlands Ranch
Lakewood
Morrison
Columbine
Sheridan
Golden
Ken Caryl
Denver homeowners · existing page
Brand + location page. Home > Doors > ProVia Doors > ProVia Doors in Denver.
Littleton homeowners · existing page
Brand + location page. Home > Doors > ProVia Doors > ProVia Doors in Littleton.
Questions
Entry and front doors, sliding glass doors, French and hinged patio doors, and larger patio configurations where the product is available. We also handle window-to-door conversions, which are structural projects rather than simple replacements.
Sometimes, but not always. If the frame is sound and the threshold is in acceptable condition, a standard replacement may be appropriate. Deterioration, water intrusion or a configuration change usually means the frame and threshold should be addressed too. We inspect all of it before defining the scope.
On-site installation is usually the shortest part. Product lead time after final measurements is typically the longest, and openings that need framing, siding or interior finish work take longer on site. You get a specific schedule during planning.
Yes, and there are real advantages. With siding off, flashing and weather-resistive barrier integration around the door is far more accessible, and trim can be coordinated with the new siding profile. See siding services
Compare by the role you need the door to play: entry systems and decorative glass, premium architectural patio systems, broad multi-category selection, or value-oriented patio replacement. Materials, glass and hardware options vary by product line, so we compare specific configurations rather than brand names.
Permit requirements vary by jurisdiction and project scope. Structural changes to an opening commonly require additional review and may require permits or engineering. We confirm the requirements for your specific project and jurisdiction during planning.
Door type, manufacturer, material, size, glass, sidelites and transoms, hardware, finish, the condition of the frame and threshold, trim, structural opening changes, siding work, interior finish and any deck or landing work. See the cost drivers
Yes. Sliding patio doors are one of the most common door replacements we handle. Panel count, rollers, tracks, screens and glass all get selected against how the opening is actually used — and we check the sill and threshold condition before ordering.
Often, but it depends on the opening width, the framing and the clearance you have inside and outside for swinging panels. Changing configuration usually means the opening is treated as a more involved replacement rather than a like-for-like swap.
Sometimes — it is not possible in every wall. We evaluate wall construction, utilities, opening width, framing and header requirements, exterior and interior finish, weatherproofing and any deck or landing needs, then confirm permitting. See how conversions work
Yes. Because GS also builds decks, the opening location, threshold transition and landing or stair access can be planned together instead of one trade working around the other. See deck services
A combination of the door and frame assembly, glass configuration, weatherstripping, threshold detail and how well the whole unit is sealed and flashed into the opening. ENERGY STAR eligibility and NFRC ratings depend on the specific product configuration, not on the manufacturer name.
Door consultation
Two short steps. The more we know about the existing opening, the more useful the first conversation is — photos of the inside and outside help most.
Prefer to talk? (720) 608-4773
