Basement Window Cost in 2026: Hopper Replacement, Glass Block, and the Bedroom Egress Question

What a standard basement-window replacement costs

RemodelingExpense's June 20, 2026 guide lists $400–$800 installed for a basic basement hopper, with a broader basement-window range of $400–$1,200. Its scope covers existing small foundation openings; it explicitly separates projects needing a bedroom exit, major foundation cutting, or a new well. These are publisher planning estimates, rather than a price for either named product below.

Angi's August 1, 2026 article gives $400–$1,000 per replacement basement window in its cost insights. This Old House's June 23, 2026 glass-block guide lists $150–$1,000 installed for prefabricated glass block. The ranges overlap, but they describe different assemblies and source methods. Neither establishes a universal saving from choosing glass block over an opening sash.

This page prices replacement within the existing opening. If the proposal includes cutting or enlarging the foundation, excavation, a structural header, or an escape well, use the separate basement egress-window cost guide. Before seeking bids, write down the room's current and intended use and ask the local building department which opening requirements apply. A window order should follow that determination.

Installed prices and unit prices need separate columns

Keep the publisher's scope attached to each figure. A small window sold on its own and a complete replacement job are different purchases.

Sources: RemodelingExpense's cost-by-type table, Angi's prefab-unit table, and This Old House's installation discussion. This Old House attributes its article's averaged figures to Angi, Home Advisor, and Fixr; it is not an independent local bid survey.

The custom glass-block row includes jobs beyond a standard small basement swap. Do not use its upper end as the expected price for a stock hopper opening. Conversely, a low prefab unit price leaves the removal and installation commitment unanswered. Adding a generic labor allowance to a catalog price would create an estimate that these sources did not publish.

The sources also use different headline and category ranges. This Old House's opening summary differs from its specifically labeled installation ranges. The table preserves the scoped installation figures rather than blending every number into a new range. For your project, ask each bidder to identify the complete installed total and list any excluded repairs beside it.

Two named products: opening vinyl versus fixed glass block

The comparison below draws construction details and coverage from actual manufacturer PDFs. It gives you specifications to request in an order, without attaching an invented brand price to them.

Sources: BH100 brochure, PDF page 2, Northeast residential warranty, PDF page 2, Hy-Lite catalog, printed page 26, and Hy-Lite warranty, glass-block provision. Coverage is subject to each document's conditions.

The judgment row follows from the documented operation. The BH100's full opening angle makes clearance a question for the actual basement layout. The fixed Hy-Lite assembly cannot be evaluated as though it had an operating sash. Have the seller show how either proposed assembly serves the particular opening, then have the authority confirm any required function.

These dimensions describe different parts of the products. Frame depth and individual block thickness cannot rank whole-window insulation. Nor can a block's dimensions establish the completed window's outside size. Request the manufacturer's drawing for the exact assembly and compare it with the measured opening before authorizing manufacture.

Glass block and acrylic block are separate orders

Hy-Lite's catalog, printed pages 19 and 24, separately describes acrylic block windows and lists operable hopper, awning, and casement styles. Its True Glass Block section, printed page 26, lists a fixed style. A proposal saying only “Hy-Lite block window” therefore leaves both material and operation unresolved.

Ask for the full product description, material, frame, pattern, size, and operating style. If you want privacy and ventilation together, have the dealer identify the actual operable product. Do not assume the glass-block window in the comparison table can acquire a hopper sash merely because another section of the catalog offers hoppers.

The catalog describes Wave and Ice patterns for the true-glass product. Ask to see a representative sample in the lighting conditions you care about. Treat privacy as something to inspect: request a demonstration of what remains visible through the selected pattern rather than accepting an undefined description such as “privacy glass.” Keep the approved pattern on the order.

If a seller proposes an acrylic alternative, request its own warranty provision. Hy-Lite's warranty separates acrylic block, glass block, and decorative glass. A term or remedy belonging to one heading should not be transferred to another. Have the dealer mark the provision governing the exact product being supplied.

Measure the opening and demonstrate sash clearance

The BH100 brochure gives a 3-1/4 inches frame depth, custom sizing to the nearest 1/4 inch, and a full 90-degree vent angle. Those are useful ordering facts; they are not permission to estimate the purchase size from the visible glass. Ask the bidder to document the opening measurements and how the proposed frame fits them.

Have the installer identify what remains around the opening. Mark any retained frame or wood buck on the proposal drawing. Ask which measurement controls the custom order, who takes that measurement, and who is responsible if the supplied assembly does not fit. Keep the final measurement schedule with the signed order rather than accepting an unexplained size code.

For sash clearance, show the bidder the finished ceiling, shelves, pipes, blinds, and planned furniture near the opening. Ask for the open-sash position to be marked on a section or demonstrated with the product. Include both the normal ventilation position and the manufacturer's prescribed cleaning access. A fully opening catalog sash needs room in your finished room.

Request a demonstration of reaching the locks and screen from the actual floor level. Describe any access difficulty before ordering, and ask the seller to show the proposed operating procedure. If the window serves a required escape function, have the local authority review the clear passage and operation separately. A cleaning maneuver or removable sash should not silently become the claimed everyday opening.

Match the glass specification to its coverage

The BH100 brochure specifies an insulated glass unit and a high-performance warm-edge spacer system. Northeast's warranty identifies standard insulating glass with Quanex Duralite spacers in its seal-failure provision. Ask the dealer to confirm the actual glass and spacer on the order and identify the applicable coverage. A generic warm-edge description does not establish a named spacer.

Request the glazing specification alongside the frame size. Have the supplier identify any selected coating, gas fill, obscure pattern, or safety glazing and supply the performance documentation for that configuration. If alternatives are available, ask for separate complete installed totals with the same opening and repair scope. Compare what each order actually specifies rather than treating insulated-glass thickness as a complete performance description.

Preserve the confirmed glazing description through delivery. If the dealer substitutes a component, request the revised specification and any change to coverage before accepting it. Keep the original and revised descriptions with the purchase documents so that a future glass claim can identify what was supplied. For a question about fogging, ask which warranty condition the observed problem meets and what evidence the manufacturer requires; do not assume every visible moisture concern is a covered glass-seal failure.

The surrounding opening belongs in the replacement scope

RemodelingExpense identifies rusted steel frames, rotted wood bucks, masonry fit, sill condition, and below-grade access as basement-specific cost influences. Its basic range should be read alongside those conditions. The installed total needs to say what the company will do to your opening, not merely which window it will deliver.

Ask the bidder to describe removal of the existing unit and any retained perimeter material. Request the proposed preparation, fastening, sealing, interior trim, exterior finish, and disposal. Have the company distinguish work included in the price from conditions that require a change order. Photographs with a marked opening can help make the scope understandable to both parties.

For visible deterioration, ask for the repair itself to be described and priced. Avoid treating a new frame covering the old perimeter as evidence that the underlying condition has been resolved. Have the installer explain the proposed connection and identify the sound material it will use. If assessment requires removal first, agree on documentation and approval of additional work beforehand.

Ask how the opening will be protected while the existing window is out and how restoration will be completed. Identify who patches the interior and exterior surfaces, who applies the final finish, and whether that work occurs during the same visit. These are contract questions; there is no sourced universal repair allowance to add here.

Treat water concerns as a documented condition

Tell the bidder where and when you have seen water, staining, or dampness. Show photographs if the condition is intermittent. Ask whether the inspection found a product defect, a perimeter problem, or exterior work that needs separate evaluation. Request the observation and proposed response in writing rather than assuming replacement alone addresses every cause.

The Northeast residential warranty, PDF page 3, excludes problems associated with failure to properly flash, insulate, or secure the window. Hy-Lite's warranty separates installation caulking from the manufactured product. Both documents make the installation commitment worth reading alongside the product warranty.

Ask who owns each part of that commitment. If another company will handle exterior drainage or foundation repairs, request a schedule coordinating that work with the window installation. Have each company state the limits of its scope. A shared photograph and written description are more useful than an assumption that the other trade has accounted for the junction.

At completion, request the care instructions and an explanation of the installed perimeter details. Record any unresolved water concern before final acceptance. If the installer proposes later observation, have the follow-up arrangement documented, including whom to contact and what evidence to collect. Keep that service commitment separate from the manufacturer's coverage term.

A new basement bedroom changes the opening question

Oregon's 2023 ORSC amendment-summary document, printed page 62, R310.7, states: “New sleeping rooms created in an existing basement shall be provided with emergency escape and rescue openings in accordance with Section R310.1.” This is a jurisdiction-specific code quotation, not a nationwide determination for your house.

The Oregon Residential Specialty Code program identifies its scope as construction, reconstruction, and repair of one- and two-family dwellings and townhouses. Oregon's R310.1 amendment, effective October 1, 2024, addresses basements and sleeping rooms, including a required opening in each basement sleeping room and specified exceptions. Its sprinkler exception depends on the specified basement egress arrangements; it does not exempt every sprinklered basement automatically.

The 2023 amendment summary's R310.5, printed page 61, exempts qualifying replacement windows specifically from Sections R310.2 and R310.4.4, rather than from every escape-opening requirement. Its conditions include work that is not part of a change of occupancy or use. The replacement must also be the manufacturer's largest standard size fitting the existing frame or rough opening and have the same operating style or provide equal or greater opening area. Ask the building department to determine which provision applies to your room use before ordering.

R310.7 expressly accepts an operable window complying with R310.7.1, printed page 62, as an exception. It also says that alterations or repairs other than new sleeping rooms do not require an emergency escape and rescue opening under that provision. Its presence matters: a general summary of new-opening dimensions does not resolve every existing-building project. Take the existing window information and proposed room plan to the reviewing authority. Request the applicable dimensions, operation, exterior route, and any required permit scope in its response.

This page does not price an egress cut-in or reproduce the companion guide's foundation-work budget. If the authority requires an escape opening that the existing assembly cannot provide, ask for a separately described project and consult the egress-window cost guide. The decision precedes choosing a fixed glass-block replacement for that opening.

A hopper name does not prove a clear escape opening

The BH100 brochure documents an opening angle and construction details. It does not give a net-clear escape-opening schedule for the ordered size. Request that evidence from the supplier if the opening has an escape role. Outside frame dimensions and an opening angle alone leave the useful passage unanswered.

Oregon's R310.2.2, printed page 60, bases clear dimensions on normal operation. Ask the supplier to identify the passage remaining with the sash and hardware in their normal open position, then ask the authority to assess it against the applicable provisions. Do not assume a window becomes acceptable because its glass or sash can be removed for service.

For a fixed block proposal, tell the reviewing authority that it has no operating sash. If a seller instead offers a vented panel, request the vent's own opening dimensions and operating description. Have the complete assembly reviewed. A ventilation feature and an emergency passage are distinct specifications, and the quote should identify the function it is claiming.

After approval, preserve the agreed configuration through delivery. Require renewed opening evidence for a substitution that changes the sash, hardware, or passage. Ask who checks the installed operation against the approved specification. This gives the purchase a clear acceptance condition without this article declaring a particular window code-compliant.

Read the BH100 warranty beyond the lifetime headline

Northeast's residential warranty, effective January 1, 2024, separately covers vinyl integrity, nonglass components, insulating glass, finishes, and service. Its lifetime vinyl material provision excludes warping and color fading. Hardware and other nonglass components have a general ten years of manufacturing-defect coverage; the separate screen provision limits screen-component hardware to one year after manufacture and excludes specified mesh damage. Qualifying standard insulating glass with the specified spacer has twenty years of seal-failure coverage in the stated smaller-size category; the document includes prorating conditions. Its nonglass provision also excludes non-stainless-steel hardware finishes in coastal environments.

The PDF's service section provides up to one year of free in-house labor and necessary site visits, followed by billable terms. Its remedy section separately excludes removal, installation, finishing, refinishing, and disposal. Ask the dealer to explain warranty labor for the proposed claim work rather than interpreting a free-service statement as complete replacement installation coverage.

Have the dealer provide the warranty applicable to the purchase and occupancy. The PDF identifies residential eligibility and says it is not fully transferable; commercial projects use different terms. If the basement is part of a rental or another arrangement, describe that use and request the governing document. Keep proof of purchase and the product identification with it.

Ask the installer for its own workmanship agreement. Identify the contact for an installation issue, the contact for a manufacturing claim, and the costs each party agrees to handle. If the dealer offers additional service, have its duration, territory, exclusions, and surrounding restoration stated in writing. The longest manufacturer term cannot answer those contract details.

Hy-Lite's glass-block term covers defined defects

The Hy-Lite warranty, effective February 1, 2024, gives glass-block products five years of limited coverage against discoloration, seal breakage, defective materials, or workmanship. Broken or cracked blocks are excluded. The document describes replacement parts and an option to refund the original product purchase price if replacement is impractical.

Request the glass-block provision with the quote and ask the seller to explain the installation costs attached to the applicable remedy. The warranty contains separate language for other product categories; use the heading governing your order. Also ask who restores the surrounding opening if a covered part needs service. Do not infer that responsibility from a product replacement promise.

Hy-Lite's PDF treats installation caulking as outside the manufactured product's warranty and describes it as a homeowner maintenance responsibility. Ask the installer to explain the supplied care instructions and identify its own perimeter-work coverage. Preserve those instructions with the product warranty so that later service questions can refer to the installed system.

Before handover, compare the product, size, pattern, finish, and operation with the signed order. For an operating hopper, request a demonstration of opening, closing, locking, screen handling, and prescribed cleaning. For fixed block, compare the actual assembly with the approved specification and agreed installation scope. Record any unresolved difference while the installer can still address it.

What we could not verify

All sources used for the claims above were reachable during this review.

Questions to ask before you compare quotes

• Does this quote replace the window within the existing foundation opening?
• Is the room remaining a utility space or becoming a sleeping room?
• Does the proposed sash have room to open fully inside the basement?
• Who covers removal, installation, and surrounding repairs during a warranty claim?

Sources

All retrieved 2026-09-30.

1. RemodelingExpense, "Basement Windows Cost: 2026 Installed Price Calculator" — visible article and cost-by-type table, rather than calculator output.
2. Angi, "How Much Does Basement Window Replacement Cost? [2026 Data]" — direct HTTP fetch returned 403; visible article retrieved with web open.
3. This Old House, "How Much Does Glass Block Window Installation Cost? (2026 Guide)" — specifically scoped installation ranges; publisher aggregates other cost sources.
4. Northeast Windows USA, "The BH100 Series — Hopper" (primary-document extraction).
5. Northeast Windows USA, "Terms of Service & Limited Lifetime Warranty," effective January 1, 2024 (primary-document extraction).
6. Hy-Lite, "2026 Catalog," September revision (primary-document extraction).
7. Hy-Lite, "Limited Warranty," effective February 1, 2024 (primary-document extraction; broken text mappings required visual inspection of the rendered PDF).
8. Oregon Building Codes Division, "Summary of Amendments — 2023 ORSC," printed pages 60–62 (primary-document extraction; R310.2.2, R310.5, R310.7 and R310.7.1).
9. Oregon Building Codes Division, "2023 Oregon Residential Specialty Code Amendments — R310," effective October 1, 2024 (primary-document extraction; current R310.1 and its exceptions).
10. Oregon Building Codes Division, "Residential Structures Code Program" — code applicability to one- and two-family dwellings and townhouses.