Updated September 2026. Specifications from each manufacturer. How we research products
Andersen 100 Series
- Manufacturer
- Andersen
- Material
- Fibrex composite: wood fibre in thermoplastic polymer
- Positioning
- Andersen’s value line
- Warranty
- Owner-to-Owner, transfers; 10 years non-glass per dealers
Marvin Essential
- Manufacturer
- Marvin
- Material
- Ultrex fiberglass, inside and out
- Positioning
- Marvin’s practical fiberglass line
- Warranty
- 10 years non-glass, 10 to 20 on glass; transfers; labor excluded
Main difference: composite against fiberglass. Essential sits in the higher fiberglass price territory and offers double-hung windows and custom sizing in 1/64 inch steps; the 100 Series has no double-hung. Both warranties transfer and neither is lifetime, but Marvin’s remedy explicitly excludes removal and installation. Illustrations are UpgradeWorth drawings, not product photographs. No winner is declared.
UpgradeWorth has not physically tested either product. This comparison is built from manufacturer product pages, warranty documentation and dealer material, with the source named beside anything that is not from the manufacturer.
These two lines are pitched at the same homeowner: someone who has decided vinyl is not the answer but does not want a luxury collection. They arrive there by different routes, and the warranties are almost mirror images of each other.
Side by side
| Andersen 100 Series | Marvin Essential | |
|---|---|---|
| Frame material | Fibrex composite, not vinyl and not fiberglass. Andersen describes Fibrex as a proprietary composite of reclaimed wood fiber and thermoplastic polymer, stating it is composed of 40% reclaimed wood fiber by weight, most of it reclaimed from the manufacture of Andersen wood windows, and that it is twice as strong as vinyl | Ultrex fiberglass inside and out. Marvin states Ultrex is 8 times stronger than vinyl and 3 times stronger than wood-vinyl composites, has a low thermal expansion rate, is heat resistant and non-corrosive, and expands at virtually the same rate as glass. Marvin states Ultrex contains no sawdust or vinyl |
| Styles | Single-hung, casement, awning, gliding (sliding), picture and specialty shapes, each with its own product page on andersenwindows.com. Andersen also offers 100 Series gliding and hinged patio doors | Double-hung, casement, awning, glider, picture and direct glaze, plus specialty shapes including round top, trapezoid, triangle, pentagon and octagon; patio doors are offered in the same collection. Custom sizes available in 1/64 inch increments |
| U-factor | Not published by Andersen as a single range. One dealer page cites a 0.29 U-factor with 0.21 SHGC for a configuration it sells; a third-party guide cites 0.27 to 0.30. Configuration dependent: check the NFRC label on your quote | Not published by Marvin as a single range. Performance data is published per product in Marvin's product resources. Configuration dependent: check the NFRC label on your quote |
| SHGC | Not published by Andersen as a single range. Dealer-cited 0.21 for one configuration. Configuration dependent | Not published by Marvin as a single range. Configuration dependent |
| ENERGY STAR | Andersen states many 100 Series configurations are ENERGY STAR certified, and certification depends on the glass package and the climate zone rather than on the series as a whole | Marvin states Essential is available with ENERGY STAR certified glass options; certification follows the glass package and the climate zone |
| Warranty | Andersen Owner-to-Owner limited warranty, which Andersen states is transferable when the home is sold. Dealers consistently describe the 100 Series terms as 20 years on glass and 10 years on non-glass components, with exterior finish covered against flaking, blistering, cracking, pitting, corrosion and loss of adhesion for 10 years. Read the current warranty document at andersenwindows.com/support/warranty before purchase | Marvin Limited Warranty (effective January 12, 2026), fully transferable to later owners of the structure. Insulating-glass seal: 20 years up to 60 sq ft, 10 years at 60 sq ft and larger. Non-tempered glass stress cracks: 10 years. Hardware and other non-glass components: 10 years. Standard exterior fiberglass (Ultrex) cladding finish: 10 years (AAMA 625). Factory interior coated composite finish: 10 years. Labor is not covered: removal, installation, finishing, refinishing and disposal costs are excluded. Claims within 60 days of the defect appearing. Not a lifetime warranty (Infinity by Marvin is a separate brand with its own terms) |
| Price position | Not publicly specified | Not publicly specified |
| Installation | Replacement (insert) and new construction; sold through Andersen dealers, certified contractors and the Andersen at Home Depot program | Replacement, remodeling and new construction, sold through Marvin dealers |
Specifications from each manufacturer. Empty fields mean the value is not publicly specified, not that it is zero.
The materials, stated accurately
Andersen 100 Series is Fibrex composite. Andersen describes it as reclaimed wood fibre and thermoplastic polymer, 40% wood fibre by weight, most of it recovered from its own wood window manufacturing, and states it is twice as strong as vinyl and blocks thermal transfer nearly 700 times better than aluminium.
Marvin Essential is Ultrex fiberglass, inside and out. Marvin states Ultrex is 8 times stronger than vinyl and 3 times stronger than wood-vinyl composites, that it contains no sawdust or vinyl, and that it expands at virtually the same rate as glass.
Read those two paragraphs together and the marketing collides: Marvin’s comparison class, wood-vinyl composites, is essentially what Fibrex is. Both sets of figures are manufacturer tests with manufacturer definitions, and neither is independently verified. What you can take from them is direction, not a score.
Styles: the practical filter
Andersen’s 100 Series offers single-hung, casement, awning, gliding, picture and specialty shapes. There is no double-hung window in the line. Marvin Essential offers double-hung, casement, awning, glider, picture and direct glaze, plus specialty shapes, and builds to custom sizes in 1/64 inch increments.
On a house full of double-hung windows where both sashes need to operate, that difference settles the comparison before anyone discusses material.
Warranty: opposite philosophies
| Andersen 100 Series | Marvin Essential | |
|---|---|---|
| Headline | Owner-to-Owner limited warranty, which Andersen states transfers when the home is sold | Limited Warranty, explicitly not a lifetime warranty |
| Glass | Dealers consistently describe 20 years | 20 years under 60 sq ft, 10 years at 60 sq ft or more, per Marvin’s own document |
| Non-glass components | Dealers describe 10 years | 10 years, per Marvin’s own document |
| Finish | Exterior finish covered 10 years against flaking, blistering, cracking, pitting, corrosion and loss of adhesion, per dealer documentation | Exterior cladding finish 20 years per AAMA 2605-11; interior finishes 5 to 10 years |
| Labour | Not covered by the manufacturer | Removal, installation, finishing, refinishing and disposal explicitly excluded |
| Where the terms come from | Headline on Andersen’s pages; component terms from dealer documentation | Marvin’s published Window and Door Limited Warranty |
Read the current documents before signing: Andersen and Marvin.
The philosophies differ in a way that suits different buyers. Andersen leads with transferability, which favours a homeowner who may sell. Marvin publishes the component terms plainly and does not claim lifetime coverage at all, which favours a homeowner who wants to know exactly what is covered and for how long.
Appearance and maintenance
Both are low maintenance: neither needs painting, and both offer dark exteriors that vinyl struggles with. Andersen warrants the 100 Series finish for 10 years against flaking and fading; Marvin’s acrylic finish is AAMA 624 verified and, Marvin says, around three times thicker than competing painted options.
Frame profile differs by product rather than by material class, so compare the visible glass area on the actual units quoted rather than trusting the brochure photography.
Energy performance
Neither publishes a collection-wide U-factor range, because certification follows the glass package. A dealer cites 0.29 with 0.21 SHGC for a 100 Series configuration; Marvin publishes performance per product in its Essential resources. The gap between two glass packages inside either line is wider than the gap between the lines, so compare NFRC labels, not brands.
Availability and installation
Andersen’s 100 Series reaches homes through Andersen dealers, certified contractors and the Andersen at Home Depot programme. Marvin Essential is sold through Marvin dealers. In both cases the installer is a bigger variable than the product: labour sits outside both warranties, and the insert or full-frame decision moves the price more than the material does.
Consider Andersen 100 when
- You may sell within a decade and want coverage that transfers
- Your openings are casement, gliding, picture or specialty shapes
- You want dark exteriors at the lower end of this pair’s price territory
- Home Depot availability or a local Andersen installer is the strongest option quoting you
Consider Marvin Essential when
- You need double-hung windows, which the 100 Series does not offer
- Openings are non-standard and custom sizing in fine increments helps
- You want the warranty terms published in one document rather than assembled from dealer material
- You prefer an all-fiberglass frame to a wood-fibre composite
Consider something else when
- You want a wood interior: price Marvin Elevate or the Andersen 400 Series.
- Budget is the binding constraint in a moderate climate: a quality vinyl line does the job. See vinyl vs. fiberglass.
- Your frames are rotted: the installation method matters more than either brand.
What we could not compare
Neither manufacturer publishes a like-for-like U-factor range, visible transmittance or installed pricing. Andersen’s component warranty terms come from dealer documentation rather than its own product pages. We have not tested either window and publish no satisfaction ratings.