FRAME MATERIALS
Vinyl, Fiberglass or Wood
The frame material is settled before anyone measures, and it moves the price of the job more than any other single choice. This page is the comparison between the three; each one then has a page of its own.
- No obligation
- Independent of any manufacturer
- We install nothing ourselves
What actually separates them
Three genuinely different answers to the same question — not three grades of the same thing.
| Question | Vinyl | Fiberglass | Wood |
|---|---|---|---|
| What it is | Extruded PVC, hollow and chambered. | Glass fibre set in resin, pultruded. | Solid timber, often clad on the outside. |
| Color | Runs through the material, so a scratch shows the same color underneath. Chosen at the factory. | Painted or factory-finished, and it holds dark colors in sun better than vinyl does. | Finished, and refinishable in another color later. |
| Movement in heat | Moves more than the glass it holds. | Moves at close to the rate of the glass. | Moves with moisture more than with heat. |
| Upkeep | Wash it. There is nothing to refinish. | Wash it. Repaint only to change the color. | Refinishing on a cycle, unless it is clad outside. |
| When it fails | Replaced. | Replaced. | Can be repaired and refinished. |
| Who quotes it | Almost every company in every market. | Fewer companies, so fewer competing quotes. | Specialists and higher-end suppliers. |
No cost, lifespan or expansion figures appear in this table. The only sources for those are manufacturers' own material, and a warranty length is not a measurement of service life.
The efficiency question is the wrong question
It is the one most often asked about frame materials, and the answer disqualifies the premise.
ENERGY STAR certifies windows in fiberglass, vinyl, aluminum, wood and combination frames, and no specific technology is required for certification. The criteria are performance figures — a U-factor and a solar heat gain coefficient, which vary by climate zone — and any of these materials can meet them or miss them.
So “which material is most efficient” has no answer at the level of the material. Two vinyl windows from one manufacturer can sit on either side of the line, and a certified fiberglass unit and a certified vinyl unit in the same zone are meeting the same numbers. What decides the outcome is the glazing package and the certified figures on the exact unit being quoted. The figures that do decide it are here.
Where the default holds, and where it stops
Read this as a shortlist rather than a ranking. No material wins outright — the opening, the climate and the budget decide it.
Why the choice is usually vinyl
- Every company in your market quotes it, so comparable prices are easy to collect.
- It is what US replacement work defaults to, so it is the material most quotes are built around.
- Nothing to maintain beyond washing it.
- Color runs through the material, so surface damage does not expose a different color underneath.
Why to look past it
- The frame is wider than fiberglass for the same opening, so a large window loses more glass area to it.
- Dark colors in full sun are the combination it likes least.
- It moves more than the glass it holds when the temperature swings hard.
- A historic district may not accept it at all.
Go into the depth on one
Each page carries the same sections in the same order, so any two of them can be read side by side.
Vinyl
The default. What it does well, where frame width starts to matter, and what to ask about the welded corners.
Vinyl windows in full →Fiberglass
The case for paying more, when it holds, and why fewer installers put it in front of you.
Fiberglass windows in full →Wood
Clad against solid, what the maintenance actually involves, and when a district decides for you.
Wood windows in full →
Aluminum is not one of the three, and that is deliberate
It is still fitted in commercial work and in some warm-climate residential jobs, and ENERGY STAR certifies it like any other frame. It also conducts heat far better than the three above, which is the opposite of what a replacement window is being bought to do — so it stays an option inside a quote rather than a page arguing for it.
What the frame choice does not settle is the price of the job, which moves with the opening count, the scope and the glazing before it moves with the material. The published national ranges are here, attributed to the surveys that produced them.
Material questions
Decide the material before the visit
A quote built on a different frame material is a different job at a different price. Settle this one, then ask three companies to price the same thing.