1. Observe and protect
Write down the symptoms, limit further damage where safely possible, and collect background history on the property.
2. Evaluate the house and site
Evaluation covers install method, flashing, sill condition, frame material, glass package, and trim restoration -- all as important as the unit chosen.
3. Define a written scope
Get preparation, protection, materials, access, permits, testing, cleanup, restoration, exclusions, and change-order terms in writing up front.
4. Compare providers
Confirm credentials, then weigh the reasoning and boundaries in each proposal instead of comparing totals alone.
5. Inspect closeout
Final inspection should confirm testing, cleanup, documentation, warranty coverage, and remaining maintenance duties.