Start with what the existing window needs
Make a room-by-room list of drafts, difficult operation, damaged seals and unwanted afternoon sun. Ask whether a problem can be addressed through maintenance, suitable shading or an authorized repair before assuming every window must be replaced. A replacement proposal should identify the problem it is meant to solve.
Read the ratings rather than the sales label
NFRC provides independent window performance ratings. U-factor concerns heat transfer; a lower value generally indicates less heat transfer. Solar heat gain coefficient describes how much solar energy enters through the window. Visible transmittance concerns daylight. Compare the actual proposed product and glass configuration, not a showroom example with different specifications.
The best combination depends on the local climate, orientation and the room. Ask the installer to explain the tradeoff between limiting unwanted heat and retaining useful daylight. Do not assume the darkest glass or the most expensive frame is best for every opening.
Compare the complete installation
Product ratings are only part of the decision. Ask how the opening will be prepared, flashed and sealed; how drainage will be protected; and what interior or exterior repairs are included. Clarify who handles permits and inspections. Request exact model names and ratings on the written proposal so competing quotes can be compared fairly.
Include exclusions and warranty responsibilities. If a proposal changes the opening size or alters the building, ask the relevant professional which additional approvals are needed. A generic quote described only as “energy-efficient windows” is not enough to check a rebate or compare performance.
Check assistance without assuming reimbursement
LADWP's Consumer Rebate Program lists qualifying window measures, but technical requirements and installation rules apply. Use the current program terms to check the precise product before purchase. An ENERGY STAR or NFRC label alone is not proof that every local rebate requirement is satisfied.
Keep invoices, model information and any required installation records. Do not include a new federal home-improvement credit in a 2026 purchase calculation without current IRS support.
Renters and useful alternatives
Tenants should request permission before changing windows, applying products or installing permanent shading. Report drafts or damaged components to the property manager with photos and dates. Ask which low-impact comfort measures are allowed in the residence.
Compare the full installed cost with the actual problem being solved. We have not calculated household-specific savings here. A comfort improvement can be valuable without supporting a guaranteed payback claim.