Choosing whether to replace siding and windows together or in two steps changes cost, timing, and water control. This guide shows how each piece ties into flashing, housewrap, and trim. Done in the right order, the wall stays dry and the finish stays clean.
We explain when to bundle, when to split, and the basic order of work. You’ll see leak hot spots, permit checks for Northern Illinois, and simple cost drivers for 2025. The goal is a clear scope and less rework.
The 60-Second Answer: Bundle Or Split?
- Bundle now if siding is failing, windows are drafty, or you plan new trim or insulation.
- Split into two phases if one system is sound, and you need to stage costs.
Key Takeaway: Bundling cuts duplicate setup and trim work. Phasing works when structures are solid and the plan protects future work.
Why Order Matters
How Flashing and Housewrap Work
Windows must lap into the weather-resistive barrier. Head flashing should tuck under the wrap. Siding then sheds water over those layers.
Where Leaks Start
Leaks often come from missed head flashing, open sill pans, and trim joints. A tight sequence stops water before it reaches the sheathing.
Should I Replace Siding and Windows Together?
Choose both at once if you will change window sizes, add foam, or update trim profiles. One crew controls the layers, so you avoid cut-backs and patching later.
Pro Tip: Ask for a wall-section drawing that shows window flange, flashing tape, WRB, and Hardie trim. A simple sketch prevents field mistakes.
Costs In 2025: Together vs Phased
What Drives Price in Chicago
- Mobilization, scaffolding, and protection
- Materials: James Hardie siding, Pella or Marvin windows, ProVia doors
- Trim details, disposal, and permits
Where bundling saves: one setup, one trim pass, one cleanup. Where it might not: custom window sizes or major framing fixes.
Need expert help with exterior replacement? Contact All Star Products for a free consultation.
When To Replace Siding First
- Soft or swollen boards, peeling paint, pests, or clear water damage
- You plan to add foam or a rainscreen to boost comfort
- You want a fresh trim layout now and will swap windows later
We prep clean returns and leave nail fins accessible so future window work ties in fast.
When To Replace Windows First
- Fogged glass, rot, or frames that no longer open
- Siding still has life and looks good
- You want inserts now, then a full siding refresh later
We seal inserts and set flashing so new siding can integrate without tear-offs.
Energy And Comfort Gains
New glass with the right U-factor and SHGC for our climate reduces drafts. Tight housewrap and caulk lines stop air leaks. Together, the wall stays warm and dry.
Key Takeaway: The biggest comfort jump comes from sealing the frame, not just thicker cladding.
Codes, Permits, And Warranties
Chicago-area work may require permits for window size changes and safety glazing near tubs and doors. James Hardie and window makers expect proper flashing and WRB laps. One accountable team reduces the chance of a warranty dispute.
Talk to Our Team About Your Exterior Project
Ready for a clear plan for sidings and windows with honest costs and clean sequencing? Get a free estimate from All Star Products. We’ll inspect on site, provide custom renderings, deliver a line-item proposal in under a week, and complete your project with a spotless walkthrough.
