1. Home
2. Categories
3. Windows And Doors
4. Marvin Vs. Renewal By Andersen: How The Two Brands Compare

If you’re comparing Marvin and Renewal by Andersen, you’re likely in one of two places: either you’ve gotten a Renewal quote that surprised you and you’re looking for alternatives, or you’re shopping replacement windows generally and these two brands keep coming up.

Both companies make legitimate replacement windows. Both have decades of experience and strong warranties. But they operate differently — different materials, different product lineups, and notably different sales models. Here’s how they actually compare and how to decide which makes sense for your home.

The short answerThe most relevant head-to-head is Marvin Infinity vs. Renewal by Andersen — both are insert-replacement products. Marvin Infinity uses Ultrex pultruded fiberglass; Renewal uses Fibrex composite (wood fiber + thermoplastic). Both perform well. The biggest practical differences are: (1) Marvin’s lineup gives you more options if you want full-frame replacement or premium upgrades — Renewal sells only one product line, (2) Renewal’s in-home sales model often produces a higher initial quote with time-limited discounts, while retail dealers like Forshaw typically provide transparent, itemized pricing without the close. Material-wise, neither is categorically better — both are durable composites engineered to outperform vinyl.

Got a Renewal quote that felt high?Forshaw is an exclusive Marvin dealer in St. Louis. Bring us your quote — we’ll show you a transparent, itemized comparison.Call (314) 993-5570

The most relevant comparison: Marvin Infinity vs. Renewal by Andersen

Most articles compare “Marvin vs. Renewal by Andersen” without specifying which Marvin product. That’s a problem, because Marvin makes five different collections at different price points and Renewal makes one. The fair head-to-head is the Marvin product designed for the same market as Renewal: Infinity by Marvin.

Both Infinity and Renewal are replacement-focused, both are composite materials (not wood, not vinyl, not aluminum-clad), and both are sold through dedicated retailers — not big-box stores. That’s where the similarities end.

	Marvin Infinity	Renewal by Andersen
Frame material	100% Ultrex pultruded fiberglass	Fibrex composite (40% wood fiber, 60% thermoplastic polymer)
Product lines available	One Infinity line, plus 4 additional Marvin collections (Ultimate, Modern, Elevate, Essential)	One Fibrex line, in multiple window styles
Replacement type	Inserts or full-frame, depending on dealer	Primarily inserts
Frame warranty	Limited lifetime (original owner)	20 years on Fibrex material
Glass warranty	20 years	20 years
Hardware warranty	10 years	10 years
Labor/installation warranty	Through the installing dealer	2 years
Sales model	Retail dealer (showroom + consultation)	In-home consultation; pricing presented at appointment

Ultrex vs. Fibrex: how the materials actually compare

Both Ultrex and Fibrex are composites engineered to outperform vinyl and avoid the maintenance issues of wood. They’re philosophically similar products with different formulations. Here’s the breakdown.

Ultrex (Marvin Infinity)

Ultrex is pultruded fiberglass — millions of glass fibers pulled through a die and bonded with resin. The result is a frame material that’s 100% fiberglass, inside and out. Marvin’s published specs claim Ultrex is eight times stronger than vinyl, with a thermal expansion rate similar to glass itself — which means the frame and the glazing expand and contract at nearly the same rate, reducing seal stress over decades of temperature cycling.

The exterior finish is an acrylic coating bonded mechanically to the fiberglass during manufacturing, marketed as up to three times thicker than competing finishes. In practice, Ultrex frames hold their color and shape well in extreme climates — important in St. Louis, where the swing between humid 95°F summers and sub-20°F winter snaps creates meaningful stress on frame materials.

Fibrex (Renewal by Andersen)

Fibrex is Andersen’s proprietary composite made from 40% reclaimed wood fiber bonded with 60% thermoplastic polymer. Andersen patented the material in 1992 and developed it specifically for the replacement market. Per Andersen’s published claims, Fibrex is twice as strong as vinyl, blocks thermal transfer about 700 times better than aluminum, and has a low thermal expansion rate.

Because Fibrex contains wood fiber, it can be extruded into shapes that mimic wood window profiles with thinner sightlines than typical vinyl windows. The polymer encapsulates the wood fiber, which is what allows Renewal to warrant the material against rotting, blistering, peeling, and corrosion despite the wood content.

The verdict on materials

Both materials are credible replacement-window composites. Both are warrantied long-term against the failure modes (rot, warp, peel, crack) that affect lesser materials. Both have been in the market for decades — Fibrex since 1992, Ultrex even longer.

Per published specs, Ultrex is stronger (8x vinyl) than Fibrex (2x vinyl). Whether that strength differential matters in a typical home depends on the application — very wide picture windows, large slider doors, and oversized openings benefit more from frame rigidity than standard double-hungs do. For most replacement projects, either material will perform well for the life of the window.

What’s more likely to matter than the material itself is: how the window is installed, what glass package is specified, and which dealer is standing behind the work.

Warranty comparison

Both brands offer strong warranties, but they’re structured differently. Worth understanding the practical differences.

Where Marvin Infinity has an edge

Infinity’s frame warranty is limited lifetime for the original owner — covering Ultrex against warping, cracking, and corrosion as long as you own and reside in the home. Renewal’s Fibrex warranty is 20 years. Both warranties are transferable, but Infinity’s longer coverage on the frame is meaningful for owners who plan to stay long-term.

Where Renewal by Andersen has an edge

Renewal includes two years of labor and installation coverage as part of the manufacturer warranty. With Infinity, labor coverage is provided through the installing dealer rather than Marvin corporate. For Forshaw customers, that means our team is your point of contact for any installation issue — not a corporate warranty department.

The practical difference: Renewal’s structure consolidates everything under one company. Infinity’s structure separates manufacturer warranty (frame, glass, hardware) from installer warranty (labor). Some homeowners prefer the simplicity of Renewal’s single-warranty structure. Others prefer working with a local dealer they know.

The business model difference (and why it matters to your wallet)

Material specs and warranty terms tell part of the story. The other part is how each brand sells and prices their windows. This is where the experience of buying from Marvin and Renewal diverges most.

Renewal by Andersen: in-home consultation model

Renewal operates a vertically integrated direct sales model. You request a free consultation, a “design consultant” comes to your home, and pricing is presented during that visit. Their published process explicitly states that pricing is provided at the consultation.

In-home sales is a legitimate business model and Renewal’s parent company is highly reputable. But the format itself produces a predictable dynamic: the consultant is trained to close the sale during the visit, the initial quote is often structured higher to allow for time-limited discounts, and homeowners frequently report pressure to sign that day. Many St. Louis homeowners we talk to describe quotes in the $80,000–$120,000 range for projects we’ll quote substantially lower.

None of this is unique to Renewal. Pella runs versions of the same playbook in some channels. Several smaller replacement-window companies operate identically. But Renewal is the most prominent example of this model in the St. Louis market, and it’s the experience most homeowners are referring to when they ask about “window companies that came to my house.”

Marvin (through Forshaw): retail dealer model

Forshaw operates as a retail dealer: you can visit our showroom in St. Louis, see operable Marvin windows installed in real-world settings, and request a written quote on your schedule. There’s no time-limited discount structure, no day-of-visit close, and no “manager call” to authorize a better price.

If you’re comparison-shopping, you can take our quote home and compare it to others without pressure. If you have questions a week later, you call us back. If you’re not ready to buy for six months, that’s fine — we’ll be here.

This isn’t a moral judgment on Renewal’s model. It’s a practical observation about how the two experiences differ. Some homeowners prefer the all-in-one convenience of an in-home consultation; others prefer to shop on their own terms.

When Marvin’s broader lineup matters

Renewal sells one window: Fibrex composite, in various styles. That’s the entire product catalog. For some homeowners, that simplicity is appealing.

Marvin’s portfolio is structured differently. Beyond Infinity (the insert-replacement product), Marvin offers four additional collections, each suited to different priorities:

• Ultimate — Flagship wood-interior windows with extruded aluminum or wood exterior. Premium customization, historic-district approvals, true divided lights. The choice for older homes where preservation matters.
• Modern — Contemporary design with high-density fiberglass exteriors, narrow sightlines, and Marvin’s Connected Home automation system for motorized open/close, scheduled ventilation, and rain sensors.
• Elevate — Wood interior with Ultrex fiberglass exterior. Punches well above its price point and competes head-to-head with Pella’s Lifestyle Series.
• Essential — All-Ultrex fiberglass, like Infinity, but available for both new construction and replacement, with broader configuration options.

This matters if your project includes any combination of: full-frame replacement (recommended when existing frames are damaged or rotted), preservation requirements, large modern openings, or a mix of replacement and new construction. Renewal doesn’t serve those use cases. Marvin does.

If your project is straightforward insert replacement of double-hung windows, Infinity and Renewal are reasonable head-to-head candidates. If it’s anything more complicated, Marvin’s breadth becomes the practical advantage.

Pricing: what to expect

We don’t publish pricing because window cost varies enormously based on configuration, glass package, frame finish, hardware, installation type, and how many openings you’re replacing. A six-window project and a thirty-window project aren’t comparable on a per-window basis.

What we can say about the comparison in general terms:

• Sticker pricing: Renewal’s initial quotes in the St. Louis market are typically higher than what we quote for comparable Marvin work. Sometimes substantially — we routinely see Renewal quotes $20,000+ higher than Forshaw quotes on similar-scope projects, before Renewal applies their discount.
• Discount structure: Renewal’s pricing model often includes time-limited discount offers structured around the in-home consultation. The “final” price after discounts may still be higher than Forshaw’s retail quote, but it’s presented as a savings.
• What you actually pay: Comparing apples to apples is best done by getting written quotes from both, with the same product configurations, glass packages, and installation type spelled out. We’ll do this comparison with you if you bring us a Renewal quote.

Who should choose each brand?

Choose Renewal by Andersen if…

• You prefer the convenience of an all-in-one in-home consultation and aren’t bothered by same-day pricing decisions
• Your project is straightforward insert replacement of standard double-hung or casement windows
• You value the single-company-accountability model with Fibrex, labor, and installation all under one warranty
• You’ve worked with Renewal before and had a good experience

Choose Marvin (through Forshaw) if…

• You want transparent, itemized pricing without time-limited discount pressure
• Your project might benefit from options beyond a single composite frame product — whether that’s wood-clad Ultimate, modern Marvin Modern, or fiberglass Elevate/Essential
• You want to see operable windows in a showroom before deciding
• You’re comparison-shopping and want to take quotes home rather than decide on the spot
• You’re replacing windows in a historic district or older home where preservation considerations matter
• You want a longer frame warranty (Infinity’s limited lifetime vs. Renewal’s 20 years)

Why Forshaw for a Marvin project in St. Louis

Forshaw has been a family-owned St. Louis business since 1871. We’re an exclusive Marvin dealer for our window and door division, which means every member of our team is trained on the full Marvin portfolio — Ultimate through Infinity — and we don’t split attention across competing brands.

• Transparent, itemized quotes. You see what you’re paying for, line by line. No high-pressure close, no “manager call” for a better price, no time-limited discount expiring at midnight.
• Inserts and full-frame, both done well. We sell roughly even numbers of insert and full-frame replacements. Both have a place — the right one depends on your existing frame condition, project goals, and budget. We’ll walk you through the tradeoffs.
• Showroom with operable displays. Built-in Marvin windows and doors you can open, close, and evaluate side by side — not just samples in a frame.
• Installation standards. Trained installers following Marvin’s installation specifications, with accountability to our team from consultation through completion.
• We’ll review your Renewal quote. If you have one in hand, bring it. We’ll show you what comparable Marvin work would cost and where the differences lie.

Compare your options without pressureVisit our showroom to see Marvin Infinity and the full Marvin lineup. Bring your Renewal quote if you have one. We’ll provide an itemized comparison.Call (314) 993-5570or schedule a free consultation online

Frequently asked questions

Is Marvin Infinity better than Renewal by Andersen?Both are credible replacement windows from established American manufacturers. Marvin Infinity’s Ultrex fiberglass is published as 8x stronger than vinyl; Renewal’s Fibrex composite is published as 2x stronger than vinyl. Infinity offers a limited lifetime frame warranty; Renewal’s Fibrex warranty is 20 years. Beyond product specs, the bigger practical differences are: Marvin gives you four other collection options if Infinity isn’t the right fit, while Renewal sells one product. Marvin is sold through retail dealers; Renewal is sold through in-home consultation. Neither is categorically better — the right choice depends on your project and how you prefer to shop.

Why is Renewal by Andersen so expensive?Renewal’s pricing reflects their vertically integrated business model: their parent company manufactures the windows, employs the design consultants who quote them, manages the installation, and handles ongoing service — all under one company. That integration has real costs and contributes to their pricing structure. Their model also relies on in-home sales appointments, which is a more expensive sales channel than a retail showroom. In our experience in St. Louis, comparable Marvin work through a retail dealer is typically priced lower than equivalent Renewal scope, even after Renewal’s discount offers.

What is Fibrex made of?Per Renewal by Andersen, Fibrex is a composite material made from approximately 40% reclaimed wood fiber bonded with 60% proprietary thermoplastic polymer. The wood fiber is reclaimed from Andersen’s wood window manufacturing operations. Andersen patented the material in 1992 and uses it exclusively in Renewal by Andersen windows and in Andersen’s 100 Series (which is a different product, sold through different channels).

What is Ultrex made of?Ultrex is Marvin’s proprietary pultruded fiberglass — millions of glass fibers pulled through a die and bonded with resin, then coated with an acrylic finish. The frame is 100% fiberglass inside and out. Marvin has been producing Ultrex since the early 1990s, originally under the Integrity brand and now under the Infinity and Essential lines.

Does Renewal by Andersen do full-frame replacement?Renewal primarily sells insert-style replacement, where the new window unit goes into the existing frame opening. They’re engineered specifically for this approach. If your existing frames are damaged, rotted, or out of square — conditions where full-frame replacement is the better answer — Renewal’s product fit is limited. Marvin’s broader lineup (Ultimate, Elevate, Essential) gives you proper full-frame options.

Will Forshaw price-match a Renewal by Andersen quote?We don’t price-match in the traditional sense because Renewal’s quotes are typically already higher than ours for comparable work — there’s usually nothing to match. What we will do is provide a written, itemized Marvin quote you can compare directly. If you bring us a Renewal quote, we’ll walk through the comparison with you line by line so you can see exactly what each price includes.

Are Marvin Infinity windows worth the price?For homeowners replacing windows in homes they plan to stay in long-term, Marvin Infinity is genuinely worth considering. Ultrex fiberglass has a strong track record in extreme climates (which St. Louis qualifies as), the limited lifetime frame warranty is among the strongest in the industry, and Infinity’s sightlines and finish quality are higher than typical vinyl or basic composite windows. Whether it’s the right choice depends on your budget, how long you plan to own the home, and whether other Marvin lines might fit better for your specific project.

Can I see Marvin Infinity windows in person in St. Louis?Yes. Forshaw’s St. Louis showroom features operable Marvin windows installed in real-world settings — not just sample frames on a table. You can compare Infinity to other Marvin collections (Ultimate, Modern, Elevate, Essential) side by side, operate them, and see the finish details in person. No appointment required, though a consultation is helpful if you’re planning a specific project.

Previous Next