Cover Home Additions & ADU Nationwide

Cover Home Additions & ADU: The Los Angeles Owner’s Guide

Cover home additions and ADU construction in Los Angeles typically runs $53,100 – $153,400 for a full addition, while a detached ADU lands between $106,200 and $259,600. We stock Cover-compatible structural components, framing hardware, and finish materials for most Cover floor plans, and we can usually match your existing Cover model’s specs within one business day of an on-site measurement visit. Homeowners usually discover they need this level of work when their Cover home has outgrown the original footprint, a rental unit stopped penciling out on paper, or an aging addition developed structural movement that a simple repair won’t fix.

Call (936) 259-2607

If you’re reading this because an existing addition is pulling away from the main structure, showing drywall cracks that keep coming back, or a permitted ADU conversion was done poorly years ago, the first thing to know is this: we write the price down before any work starts, and that number doesn’t change unless you change the scope. That’s the Kingswell way, and it’s been the standard since 2004.

Which Cover Models This Applies To

Cover is not a product line with model numbers the way KraftMaid cabinets or Cambria countertops have series names. Cover is a company that designs and permits modular and panelized home additions, and the “part” that fails or needs matching is usually the connection point between the existing structure and the added volume. What we match is the structural system: Cover additions built in the last decade in Los Angeles commonly use 2×6 exterior wall framing at 16 inches on center, engineered I-joists or open-web floor trusses, and a specific roof tie-in detail that varies by whether the original house is a stucco box from the 1950s or a newer tract build from the 2000s.

Here’s the compatibility gotcha most homeowners don’t know: Cover additions built before roughly 2018 often used a specific Simpson Strong-Tie holdown pattern at the shear wall connections. Newer Cover plans switched to a different strap detail to meet updated California seismic codes after the 2019 code cycle. A panelized addition that meets current code cannot always be bolted to an older Cover foundation detail without an engineered retrofit. We verify this on-site before quoting, because guessing at the connection hardware is how you end up with an addition that moves independently from the house in an earthquake, which is exactly what the code is written to prevent. Penhallow Remodeling is an independent remodeling contractor; we’re not a Cover company, but we’ve worked on enough Cover additions across Los Angeles to know what holds and what doesn’t.

Signs Your Cover Home Additions & ADU Is Failing

• Drywall cracks at the ceiling line where the addition meets the original house. This usually means differential settlement or an undersized beam at the transition. In Los Angeles clay soil, the addition’s footing may be moving at a different rate than the main foundation, especially after wet winters.
• Doors inside the addition that stick in summer and swing free in winter. Seasonal movement is normal to a point, but if a door jamb moves more than 1/8 inch between seasons, the addition’s foundation is not isolated properly from expansive soil, and the problem compounds every year.
• A visible gap at the exterior joint where stucco or siding meets the new wall line. Water gets behind that joint and rots the framing behind the shear panel. By the time the gap is visible from the curb, you’re usually looking at framing repair, not just recaulking.
• Sloped floors in the addition, or a bounce when you walk across the room. This points to failed floor joist connections at the ledger board or an undersized beam. Los Angeles has specific floor deflection limits for habitable space, and a floor that feels “springy” is often past them.
• Cracks running diagonally from window corners in the ADU. That’s shear stress, not cosmetic settling. The wall panel may be doing its job in an earthquake, but the finish is telling you the holdown hardware or the panel nailing pattern wasn’t installed to spec.

Replacement Cost & What’s Included

A full home addition in Los Angeles runs $53,100 – $153,400. An attached ADU conversion typically $106,200 – $259,600, depending on whether you’re converting a garage or building new. There’s a $354,000 price difference between a two-room bump-out and a full permitted second unit with a kitchen and bath, and what drives that spread is not the square footage alone. It’s the foundation work (a hillside lot in Silver Lake needs more engineering than a flat lot in the Valley), the plumbing rough-in distance to the main line, whether you need a new electrical subpanel, and what the city’s plan check process requires for your specific zone. A garage conversion in Reseda, for example, often triggers less seismic retrofit than the same conversion in an older hillside neighborhood because the underlying structure is simpler.

When we quote a Cover-compatible addition or ADU repair on a failing connection, the written price includes demolition of the failed section, new framing and hardware matched to your existing Cover system, shear wall assembly to current code, drywall, finish, and paint. We also include the permit and inspection coordination, because in Los Angeles, an unpermitted addition is a liability when you sell and a red flag when you insure. Every job carries the 365-Day Done Right Promise: if the work fails inside a year, we come back and fix it at no charge, in writing, on every project. The number on day one is the number on the invoice, period.

If the repair is smaller, say a door header that needs replacing or a shear panel that wasn’t nailed off correctly, the cost drops into the $1,800 – $6,500 range depending on how much of the wall we have to open and whether finished materials underneath need matching. We’ll tell you which end of the range you’re on before we touch anything.

DIY or Call Us?

If you’re looking at a crack in the drywall and wondering whether to patch it yourself: you can absolutely patch it, but you’re treating the symptom. Give me the whole picture first, then we pick up the tools. The connection between an addition and the main structure in Los Angeles is a seismic load path. If the hardware is undersized, the strapping is missing, or the foundation is moving independently, no amount of drywall patching changes that. What you can safely check yourself is whether the gap at the exterior joint is open enough to see framing, whether doors are binding seasonally, and whether you hear any creaking that correlates with wind. What you should not do is open up a wall that contains the shear panel and start cutting into structural members without knowing which ones are carrying load.

This is not a scare tactic, it’s just how buildings work in earthquake country. A failed connection doesn’t announce itself; it waits for lateral movement and then does its damage. If you’re seeing any of the signs above, or you’re planning a new addition or ADU on your Cover lot and want a written price before you commit, call us at (936) 259-2607. We’ll come out, measure, check the connection points, and give you a number in writing.

FAQs