Wall Insulation (Drill & Fill / Netting & Filling)

Older Chicago homes were built to last — but most of them were never insulated properly, and your heating bill reflects that every winter.

A large portion of Chicago's housing stock was built decades before wall insulation became standard practice. That means millions of square feet of exterior wall space with hollow cavities — no insulation, no thermal barrier, nothing between the interior drywall and the outside air except the wall framing itself. The result is cold walls in winter, warm walls in summer, drafts that seem to come from nowhere, and heating and cooling systems that run constantly without ever making the home feel truly comfortable. At Clean Air Doctors, wall insulation is one of the most impactful services offered to homeowners in this area precisely because the need is so widespread and the results are so immediate.

The drill and fill method makes it possible to insulate existing walls without tearing out drywall or disrupting the interior of the home. Small holes are made in the wall cavity — typically from the exterior siding or interior drywall — insulation is injected to fill the space completely, and the holes are patched and finished cleanly. The netting and filling method uses a mesh backing installed inside the cavity to hold blown-in material in place, providing thorough coverage in wall sections where a simple injection approach may not achieve full fill. Both methods are minimally invasive and produce a significant improvement in thermal performance. Clean Air Doctors evaluates each wall section individually and uses the approach that will deliver the most complete result for that specific area.

The difference proper wall insulation makes is noticeable almost immediately — particularly in rooms that have always felt cold in winter or uncomfortably warm in summer regardless of what the thermostat is set to. Energy costs come down because the HVAC system is no longer fighting against walls that offer no resistance to heat transfer. And the home simply feels more comfortable to live in, room by room. Clean Air Doctors serves homeowners across Chicago, Evanston, Arlington Heights, Schaumburg, Palatine, and throughout Chicagoland. Call (773) 669-6139 to find out what your walls currently have — and what they should have.

What We Offer:

Drill & Fill Wall Insulation – Small access holes are made in the wall cavity, insulation is injected to fill the space completely, and holes are patched and finished — all without removing interior drywall or exterior siding unnecessarily.
Netting & Filling Wall Insulation – A mesh backing is installed inside the wall cavity to contain blown-in insulation material, ensuring complete and consistent fill across the entire cavity from top to bottom.
Exterior Wall Insulation Assessment – Before any drilling begins, wall cavities are checked to confirm what is currently present, identify any obstructions, and determine which method will produce the most thorough result for each section.
Blown-In Insulation for Wall Cavities – High-coverage blown-in material is used to fill wall cavities completely, reaching corners and irregular spaces that batt insulation cannot access in an existing wall.
Patch & Finish After Installation – Access holes made during the installation process are patched and finished cleanly, leaving walls in good visual condition after the work is complete.
Targeted Room-by-Room Treatment – Wall insulation does not have to be a whole-house project. Specific rooms, exterior-facing walls, or problem areas can be addressed individually based on where the need is greatest.
Pre & Post Thermal Assessment – Wall cavities are evaluated before the job and the results confirmed after installation, giving you a clear before-and-after picture of what changed.

Why Choose Clean Air Doctors for Wall Insulation (Drill & Fill / Netting & Filling)

Method Selected Based on the Wall, Not Convenience – Drill and fill and netting and filling are not the same process and do not produce the same result in every situation. Clean Air Doctors evaluates each wall section and selects the method that will achieve the most complete cavity fill — not the one that is fastest or easiest to execute.
Minimally Invasive Process – Neither method requires tearing out drywall or removing exterior siding to access wall cavities. The access holes made during installation are small, patched properly, and left in clean condition. Your home looks the same after the job as it did before — just better insulated.
Particularly Effective in Older Chicago Homes – Chicago has a high concentration of brick two-flats, bungalows, and older frame construction that were built without wall insulation. Clean Air Doctors has direct experience working in these building types and understands the cavity configurations, framing patterns, and access challenges specific to this housing stock.
Targeted or Whole-House Approach – Not every homeowner needs or wants to insulate every wall at once. Clean Air Doctors works with your priorities — whether that means addressing the coldest room in the house first or completing the full exterior wall envelope in a single project.
Clean Work, Honest Scope – Every access hole is accounted for and patched. The job scope is based on what was found during the assessment — not inflated to add material or labor. What is agreed on is what gets done.