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Alpen Windows Reviews

Read 2023 Alpen windows reviews from contractors, installers and homeowners on their most popular models and series. Read Alpen Window prices here.

[Email for his recommendations]

Editor's Alpen Windows Review

The replacement window business can get a bit complicated, especially when companies go out of business, other companies acquire them and suddenly are marketing the same basic windows under a new name. This sort of thing is obviously much more prevalent during "down" years as companies struggle with weak consumer demand. Are Alpen windows good? I think time will tell with this window manufacturer.

Typically, a company goes bankrupt and another company comes in and buys up their assets (factory, parts, trucks, etc.) and potentially keeps all of the existing ties with the distributors and/or reps that sell the product lines. It's tough to generalize because each deal is so unique -- one of the most publicized purchase was the Soft-Lite Gorell acquisition, mainly because Gorell was such a respected name in the industry.

At any rate, back in 2012, Brad Begin, who is currently the CEO of Alpen High Performance Products, purchased the assets of Serious Windows (headquartered in Sunnyvale, California). The history is interesting and somewhat ironic. Robert Clarke started Alpen back in 1981 and operated the company until 2008, when it was acquired by Serious Materials. Clarke was one of the main project managers in Serious Energy's biggest project, which was the government contract they received to replace the windows on the Empire State building - over 13,000 windows, can you imagine the cost of that project!

On a side note, according to Allison Ray at Alpen, the replacement glass for the Empire State building has already paid for itself in energy savings in under 4 years time.

When Serious Windows went bankrupt in 2012, Alpen HPP, led by Clarke, purchased the assets of Serious Windows and is now manufacturing fiberglass windows under that name.

Alpen Windows get 4.7 out of 5 stars based on 16 Alpen windows reviews below.

Tim - Site Editor - Updated in 2023

Alpen 625 Series Cost

Dane and Tim: I am looking for a little guidance on window selection for Castle Pines, CO. The elevation is 6500 feet and the majority of the windows are either south or west facing. I am replacing all the original wood windows and doors in a 30-year old home. There are roughly 30 windows and 3 sliding doors.

Bids have been all over the place. After reading reviews on your website, I contacted Alpen because they are made nearby. Surprisingly, they are the low bid even with triple paned windows. I would purchase the windows directly and have my GC install them. He has not worked with Alpen products before. I have heard good things about the Alpen product but less than stellar reviews on customer service. I have also been told the locking mechanisms tend to be stiff and harder to operate as a result of the energy efficiency. The runner up to the Alpen product would be the Kolbe. I like the Vista Luxe line but would likely be priced out. I am not sure that I like the Forgent better than the Alpen.

Based upon the bids below, can you provide any additional insight?

Window Bids:

Marvin Infinity: $74,428

Pella Impervia: $92,296

Andersen Renewal: $123,024

Kolbe Forgent: $70,529

Kolbe Vista Luxe: $99,750

Alpen 625 Series: $46,627 + installation (estimated to be $20,000)

Brett - Homeowner - from 2022

[Site Editor's Answer]

Brett, so you probably know more about Alpen than I do. From the little I know, they make a very good fiberglass window -- quite possibly better than any of the windows on your list. I know NOTHING about the Kolbe Forgent so I can't comment. I would spend some more time looking into Alpen for your own piece of mind, but that would be my frontrunner.

Dane - Site Editor - from 2022

Alpen HHP vs. Thermo-Tech

The window suppliers are steering me away from Hayfields the last yr they have had delivery problems orders not complete no screens for months after the order comes suppliers just got an email from the new CEO that said they know they have problems and will be working to resolve in the future and they are sorry for there problems that they knew that they had.

With that being said I check the pricing on the Thermo-Tech window to match the Alpen HHP #'s U-Value.0.19, R-Value 5.26, CR 69 these numbers match the Alpen HHP windows exactly and these for windows cost $8500 and with installation its $10,500 to $11,000 that's $7000ish less I have Soft-lite coming next week Monday and the Minnkota window bid really leaning towards the Thermo-Tech's same warranty.

Robert - Homeowner - from 2022

Alpen Zenith Series ZR6 vs Milgard Ultra

Dane, in the process of replacing approx 50 windows and 5 doors in my home in Arvada Colorado. I currently have 20+yr old Vetter windows and do to a hail storm insurance is covering about 1/2 of them so I’m going to replace them all. I have a contractor who regularly uses the Milgard fiberglass windows and likes them but then I have another that uses Alpen fiberglass and likes those.

I live about 10 miles from the Alpen manufacturing and corporate site so I was able to visit them and tour the factory. Although I’m as far from an expert as you can get I was impressed with Alpen and the fact they are local. That being said I respect my contractor and his thoughts about Milgard. Looking for a 3rd party perspective that know the industry. I’d appreciate your thoughts.


Randy - Homeowner - from 2021

[Site Editor's Answer]

Randy, the Alpen Zenith Series ZR6 is the better performer by quite a bit. The U-factor, R-value, and air infiltration or AI are very impressive. See the link that I sent you fro their website.

Data doesn't lie (although some of these manufacturers can get inventive with how they frame the data, but not these two in question...)

I'm not exactly sure the Milgard Ultra numbers, but there is simply no way that they stack up to the Alpen Zenith Series ZR6, which is nearly unbeatable. Having said that, I actually like the Milgard Ultra fiberglass window a lot. Just not when up against the Alpen model.

Dane - Site Editor - from 2021

Alpen Windows For A Passive House

I want high SHGC windows for a passive house. Could you help?

Richard - Homeowner - from 2015

[Editor's Response]

Paul, thanks for the question, this is one question we are hearing of with more and more frequency. While Passive Houses are less popular in the United States compared to Europe and Canada, but this is changing, albeit slowly. In terms of price and availability, here in the U.S. we will be looking primarily towards Canadian window manufacturers who either ship to the states or who have some limited distribution in the U.S. (typically in the Northern States near the U.S. Canada border, although a passive home can obviously be located anywhere.)

Whoever you are using to build your home should be somewhat familiar with these companies. Passive house windows will all be custom ordered based on the direction they face in order to maximize the SHGC or passive heat that they are able to collect. To this end, make sure to ask about the timeline to order and ship the windows to the job site. Here are three companies off the top of my head that specializes in passive home technology...

Alpen Windows



Tim - Site Editor - from 2015

Alpen Windows vs Marvin

We're in Virginia and recently had a quote on Marvin Integrity fiberglass windows with all ultrex frames.

We are also considering Alpen 525s windows.

Lastly, we looked at HiMark casement, which were less expensive than the first two.

Any opinions are much apprecaited.

Daniel - Homeowner - from 2013

[Contractor Response]

Daniel, Marvin makes a very solid fiberglass window and the Integrity all ultrex is a nice model.

I like the Alpen fiberglass window more and think the numbers speak for themselves. They tend to be quite expensive.

The HiMark casement is an excellent vinyl window and certainly one to consider. I might go with the HiMark myself, although Alpen makes an excellent window as well.

Peter - Contractor - from 2013

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