Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Cover Home Additions & ADU: The Pasadena Owner’s Guide
For a home addition or ADU in Pasadena, full construction typically runs $45,000 – $130,000, with ADU construction landing between $90,000 – $220,000 depending on size, access, and finish level. We plan and build these projects from the first walkthrough to the final inspection, and we put the written line-item price in front of you before a single drop cloth goes down. If you’re here because a Cover-related component or system failed, or you’re weighing a detached unit against a garage conversion, the most common discovery point is structural: cracked stucco at a tie-in, a roofline that isn’t shedding water the way the drawings said it would, or a foundation stem wall that settled after the first winter rains.
Which Cover Models This Applies To
Cover home additions and ADUs in Pasadena fall into three build types we see repeatedly: attached single-story additions off the back or side of a house, detached ADUs over a new slab or stem wall foundation, and garage conversions into junior ADUs. The same project often carries different names on the permit set, so we always start with the original architectural drawings and the Pasadena planning department’s stamped approvals. A detached ADU under California’s 2023 building code needs its own foundation, separate utility runs, and a 60-inch clearance path from the street if it’s in a rear yard. An attached addition shares the home’s roofline and foundation, which changes the waterproofing detail at every tie-in point.
OEM versus aftermarket matters less here than in mechanical parts, but material selection is the real compatibility question. We specify James Hardie siding, GAF roofing, and Schluter waterproofing membrane on Cover-style projects because those brands carry manufacturer warranties a homeowner can verify independently. For cabinetry and surfaces inside an ADU, KraftMaid and Cambria are our standard references, and we’ve also matched Silestone in kitchens where the homeowner wanted a specific edge profile. What fails first on an ADU in Pasadena is almost never the framing. It’s the flashing where the new roof dies into the old stucco, and the drainage line that wasn’t given enough slope because the original lot didn’t look flat until the laser level said otherwise.
Styles & brands we work with
Signs Your Cover Home Additions & ADU Is Failing
- Hairline cracks at the addition’s tie-in wall. Older Pasadena homes move on clay soil that expands and contracts with winter rains. A crack wider than a quarter-inch at the corner of a new wall signals differential settlement between the new foundation and the original house.
- Water staining on the ceiling where the new roofline meets the main house. This is the classic flashing failure. The valley or headwall detail was either lapped too short or sealed with a product that can’t take Southern California’s UV exposure. Stains appear months after the leak starts.
- A musty smell in the ADU after rain. In Pasadena’s Bungalow Heaven and Madison Heights neighborhoods, older lots have minimal slope. If site drainage wasn’t regraded correctly, groundwater wicks into the stem wall and you smell it before you see it.
- Doors or windows in the new space that won’t latch. When an addition shifts even a quarter-inch, doors bind at the top corner. This is a sign the header or the foundation hasn’t settled the way it was supposed to, and it’s worth measuring before the drywall starts telling the same story.
- Higher-than-expected energy bills after completion. An under-insulated roof assembly or a wall cavity left with gaps around the outlets costs you every month in Pasadena’s summer. We inspect insulation before drywall closes, but we’ve been called in to diagnose exactly this on projects built by other crews.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
For a Pasadena home addition, plan on $45,000 – $130,000 installed. ADU construction runs $90,000 – $220,000. Garage conversions, where the existing shell is sound, fall between $30,000 – $80,000. The range moves with foundation type (slab-on-grade is cheaper than stem wall on a sloped lot), utility distances from the main panel and sewer line, and the finish package you choose for the interior. A detached ADU with a KraftMaid kitchen and Cambria counters sits at the high end. A simple rear addition with two rooms and no plumbing sits lower.
Every one of our prices is written and line-itemed before work starts. That price includes the same protection package on every job: shoe covers at the door, drop cloths on the floors, quiet tools during family rest hours, and a photo of the clean-up before the crew leaves. It also includes the 365-Day Done Right Promise in writing. The price you see on paper is the price you pay at the end – no footnotes.
DIY or Call Us?
What you can safely check yourself: whether the crack at the tie-in widens after heavy rain, whether gutters are clear where the new roofline meets the old, and whether the floor drains in the ADU actually take water. Those observations help us diagnose faster when you call. What you should not attempt yourself: any framing correction, foundation work, roof tie-in repair, or drainage regrading. A roof tie-in done wrong leaks inside your walls and grows mold behind the drywall before you see it. Foundation work on clay soil without a proper soils report is a good way to turn an $8,000 repair into a $45,000 rebuild. If any of the symptoms above sound familiar, call us at (626) 714-2992 and we’ll walk the property with you, laser level in hand, before we ever talk about price.
FAQs
A properly built addition or ADU in Pasadena should last 50 years or more for the structure, with the roof assembly needing replacement every 20 – 30 years depending on material and exposure. The weak points are the flashing details and drainage, not the lumber, and those need periodic inspection after heavy winter rains. Call (626) 714-2992 and we’ll take a look at yours.
Yes, in most cases. Foundation settlement can be arrested with underpinning or piers, roofline flashing can be stripped and re-lapped with UV-stable material, and drainage can be corrected with regrading and new lines. A full rebuild is only needed when the structure has been compromised by years of water intrusion. We’ll give you the honest version of which one applies to your project, with the numbers to back it up.
A detached ADU in Pasadena typically takes 6 – 10 months from permit approval to final inspection. A garage conversion runs 3 – 5 months. An attached addition sits in the middle at 4 – 8 months, depending on foundation work and utility runs. Pasadena’s planning department timeline varies, and we handle the permit package from the start. Call (626) 714-2992 for a specific answer based on your property.
We order everything and schedule it for delivery when the build sequence calls for it. That means no pallet of James Hardie siding sitting on your front lawn for six weeks waiting for the framing inspection. Cabinetry from KraftMaid and surfaces from Cambria or Silestone are ordered against the written plans so they arrive when the rough-in is done. You never chase a material, and you never get a surprise backorder note at the last minute.
Written by Graham Stein, Owner, Elmstead Remodeling Pasadena at Elmstead Remodeling Pasadena, serving Pasadena and nearby areas.
