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IKO Home Additions & ADU: The Austin Owner’s Guide
Mason Remodeling Co Austin plans, permits, and builds IKO-compatible home additions and ADUs across Austin, with most projects landing between $45,000 and $130,000 for a full addition, and $90,000 to $220,000 for a detached ADU. We’re an independent general contractor, not affiliated with IKO, but we work with their roofing and building envelope products regularly. Most Austin homeowners call us after their current addition has hit a wall: a roof leak at the tie-in, a sinking pier, or an under-built ADU that never passed final inspection. Isaac Pruett, our owner, spent years doing structural work before bringing his crew to Austin, and he will tell you the same thing he tells every homeowner on the first call: tell me what’s wrong with it. We’ll figure out what it actually needs.
Key Takeaways:
- Home additions in Austin typically run $45,000 – $130,000; ADUs run $90,000 – $220,000.
- We pull permits, handle inspections, and give you a written price before any work starts.
- Every crew member is background-checked and identity-verified under The Threshold Standard.
- Our 365-Day Done Right Promise covers workmanship for a full year from completion.
Which IKO Models This Applies To

IKO makes roofing shingles, underlayment, and waterproofing membranes that end up on a lot of Austin additions and ADUs, and the compatibility questions we get are usually about the roof system, not a single “part.” If your addition or ADU was built with IKO shingles, the relevant lines are Cambridge, Dynasty, and Nordic. Cambridge is the most common on residential additions; Dynasty offers a heavier architectural profile; Nordic is a performance shingle rated for high wind, which matters in Austin’s spring storm season. The quickest way to identify what you have is to check the shingle’s nail line width and the wrappers on any leftover bundles in the garage. IKO shingles carry a printed code on the wrapper that identifies the plant and run date, and that code matters when matching color lots for a repair or tie-in.
On the ADU side, if your project was sheathed or underlayed with IKO products, the compatibility question is usually about whether the new roof plane ties into the main house cleanly. Ice-and-water shield and synthetic underlayment from IKO go down fine over new decking, but here’s the gotcha we see in Austin: if the original underlayment is a different brand, you can get wrinkles at the transition that telegraph through the shingles. We strip back to the decking at any tie-in rather than layering over old underlayment. It costs a little more and it is the only way to keep the new roofline flat and watertight. OEM IKO accessories are good; quality aftermarket flashings from brands like GAF or CertainTeed also work, but we source through our specification-grade material partnerships so the warranty on the work lines up with the products.
Styles & brands we work with







Signs Your IKO Home Additions & ADU Is Failing
- Water staining along the wall where the addition ties into the house. This is the classic Austin failure point. The original framing crew didn’t flash the transition correctly, and spring downpours push water behind the siding. It shows up months later as a brown line on the drywall.
- Shingles lifting or curling at the ridge and eaves. Austin’s heat does a number on asphalt shingles. IKO products are solid, but if the attic under the addition was vented wrong, the roof deck cooks and the shingle tabs curl up like potato chips.
- Doors inside the addition that suddenly stick or will not latch. That means the foundation under the addition has moved. Austin’s clay soil expands and contracts through the seasons, and if the piers were not set to the right depth, the floor frame shifts.
- Visible gaps between the addition’s exterior wall and the roofline. The fascia and soffit should sit tight against the wall plane. Gaps mean the framing has settled or the original crew just did not scribe it tight, and now birds and bugs are getting in.
- ADU slab cracks wider than a quarter inch with vertical displacement. Some hairline cracks are normal as concrete cures. When one side of the crack is higher than the other, the slab is moving and the structure above it is moving with it.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included

In Austin, a full home addition with IKO roofing runs $45,000 to $130,000 depending on square footage, foundation type, and whether you are adding a bathroom or kitchen to it. A detached ADU runs $90,000 to $220,000 when you factor in the separate electrical service, plumbing runs, and a second roof system. A garage conversion lands between $30,000 and $80,000. What drives the range is site work: pier-and-beam foundations cost less than a new slab on the east side’s clay, and running a sewer line forty feet from the main is a lot cheaper than eighty.
Every one of our proposals includes a written line-item price before work begins, the permit fees broken out, and the draw schedule spelled out. We do not do verbal estimates that grow on the final bill. When you accept a proposal, you are accepting a fixed number. If we find rot or foundation issues behind the wall, we stop, show you photos, and give you a written change order before we touch anything else. The IKO roof materials we install carry the manufacturer’s warranty, and our workmanship is covered by the 365-Day Done Right Promise from the completion date. If anything is not right within a year, we make it right at no cost to you.
DIY or Call Us?
If you are looking at a failing addition or ADU, the honest answer is that this is not a weekend project. The structural parts – roof tie-ins, foundation repair, load-bearing wall removal – can hurt you or damage your house if done wrong. Austin’s expansive clay and wind exposure add real variables that a YouTube video does not cover. What you can safely do yourself is document the symptoms: take photos of the cracks, mark the date, measure the gap, and check if doors stick more after a heavy rain. That evidence helps us diagnose faster. Then call us at (903) 623-1966. We will send a background-checked, uniformed technician with a photo ID badge, whose name and photo you will have before they arrive. That is The Threshold Standard, and we have held every crew member to it since 2004.
If your project has not started yet and you are just planning, that is actually the best time to call. Getting the foundation and roof tie-in right the first time costs far less than fixing someone else’s shortcut later.
FAQs

A properly built addition with IKO roofing should give you 25 to 40 years on the roof, and the structure itself should last the life of the house. The two weak points in Austin are foundation movement and roof venting, both of which we address in the design phase so you do not inherit the problem later. Call (903) 623-1966 for an exact quote on your project.
Yes, in most cases a failing addition can be repaired, whether that means lifting and re-piering a foundation section, re-flashing a roof tie-in, or sistering rotted framing. The decision comes down to how far the damage has gone and whether the original structure was built to code. Estimates are free, so call (903) 623-1966 and we will walk the site with you.
A straightforward room addition takes eight to fourteen weeks from permit to final inspection. A detached ADU usually takes five to eight months because of the separate utility connections and the additional inspections on the foundation and roof. Your written quote includes a timeline, and we hold to it barring weather or a discovery behind the walls.
We do not stock IKO shingles on the truck for full additions, because every roof is a different square count and color. We order IKO materials to match your existing roof when we are tying in, and we also work with KraftMaid, Cambria, and Silestone when the addition includes cabinetry or stone surfaces. Everything is ordered after your written proposal is approved, so there is never a guess on the invoice.
Written by Isaac Pruett, Owner, Mason Remodeling Co Austin at Mason Remodeling Co Austin, serving Austin and nearby areas.


