Kitchen remodeling
Bathroom remodeling
Home additions & ADU
Roofing
Windows & doors
Driveway & pavers
FenceFree written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable General Contractor Across Montclair
If you’re planning a renovation in Montclair, the first thing you should know is that most of the work here isn’t new construction. It’s remodels, additions, and ADU conversions on the city’s stock of 1950s-1970s tract homes. That’s the reality of a landlocked city with no vacant parcels left to build on. Our team at Toolbox Contractors knows exactly what that means for your project: tight lot lines, older slabs, stucco walls that have been there since Eisenhower was in office, and plan-check reviews that a contractor from outside the area won’t see coming. We’re familiar with every street off Monte Vista Avenue and the neighborhoods around Montclair Place. When you call (855) 382-3257, you’ll talk to someone who understands Montclair’s housing stock before you even describe your house.
Why Toolbox Contractors Is Montclair’s Preferred General Contractor Company
We get calls from Montclair homeowners who have already talked to two or three other contractors. The frustration is always the same: one guy does kitchens, another does roofs, a third does fences, and nobody wants to touch the garage conversion. That’s not how we work. As a General Contractor with full interior-to-exterior scope, we handle the whole project under one contract. One point of accountability. One schedule.
Norm Castellano runs our operation with a simple rule: if a Montclair homeowner has to coordinate between three different trades, we haven’t done our job. That’s why the same team that installs KraftMaid cabinets in a kitchen remodel off Ramona Avenue can also replace a low-slope roof and pour a paver patio, all on the same property.
What builds trust in Montclair isn’t a sales pitch. It’s walking a homeowner through the city’s zero-lot-line setback rules before they spend a dollar. It’s telling someone their 1963 stucco home has galvanized plumbing that will need replacing during a bathroom gut, before we open the walls. That’s the conversation we have on the first visit, and it’s why Montclair homeowners refer us to their neighbors.
Styles & brands we work with







Licensed General Contractor in Montclair
A Licensed General Contractor in Montclair is the person who carries the license, pulls the permits, schedules the inspections, and takes responsibility when something goes sideways. Our work in Montclair covers kitchen and bath remodels, whole-home renovations, room additions, garage conversions, and ADU construction. We also handle the exterior half of the job: roof replacement, window installation, fencing, hardscape, and siding. Most Montclair projects combine at least two of these scopes, which is where having one licensed contractor pays off.
Permit and Plan Review Experience
Montclair’s planning department sees a lot of infill work: additions squeezed onto 5,000-square-foot lots, garage conversions that brush up against side property lines. We manage the plan review, address corrections, and schedule inspections so the project stays on track. If you’re converting a detached garage that sits on the zero lot line, that triggers extra review. We know that before we draw the plans.
Kitchen and Bath Remodels That Fit the House
A 1958 stucco ranch in Montclair should not get the same kitchen layout as a new build in Ontario Ranch. We design remodels that work with the existing footprint, the old plumbing runs, and the low-pitch roof structure. In Montclair, a full kitchen remodel runs $14,000-$45,000. A bathroom remodel starts around $9,000 and tops out near $28,000 depending on whether you’re moving walls or just replacing finishes.
Residential General Contractor in Montclair
A Residential General Contractor in Montclair handles the kind of projects that come with owning an older home: additions that expand a two-bedroom into a three-bedroom, garage-to-ADU conversions, second-story builds where the lot can’t spread out, and interior guts that strip a house down to studs and rebuild it. Our team does all of it, and we’re comfortable in Montclair’s specific housing stock: single-story stucco tract homes with post-and-beam or low-pitch roofs and detached garages.
Room Additions and Second-Story Builds
Montclair lots are small. When a growing family needs more space, the options are usually adding a second story or converting the garage. We’ve done both across Montclair. A room addition in this city typically runs $45,000-$130,000. A full garage conversion with a bathroom and kitchenette lands between $30,000 and $80,000. These are real Montclair numbers, not national averages.
ADU and Garage Conversions
Montclair’s detached garages are among the best ADU candidates in the Inland Empire. Most were built as simple single-car or tandem structures with their own access from the alley or side yard. We convert them under current state law, pulling permits and managing the draw schedule. An ADU construction project in Montclair ranges from $90,000 to $220,000 depending on size, foundation work, and utility extension.
On a 1960s stucco tract home near the Montclair Plaza area, we converted a detached garage into an ADU under current state law: we pulled permits, managed the draw schedule, and handled the zero-lot-line setback review with the city. Our rough-in for the new bathroom and kitchenette passed inspection sign-off on the first try, and the owners now have a rentable unit without touching the main house’s builder-grade finishes.
Trusted Brands We Service in Montclair
Montclair homeowners recognize quality materials. That’s why we install Cambria and Caesarstone countertops, KraftMaid and Wellborn cabinetry, and Kohler or Moen fixtures rather than whatever is on sale at the big box. Our fence work uses Barrette, Master Halco, and Ameristar systems, which matters when a Montclair yard backs up to a busy street or an alley. Roofing systems from GAF, CertainTeed, and Owens Corning carry warranty requirements that only certified installers can back. We’re authorized to do that work, and we stock what’s needed locally for Montclair projects so the job doesn’t stall waiting on a part from a distribution center in another state.
See the difference
Before
After
Before
After
Before
AfterCommon General Contractor Problems We See in Montclair Homes
- Garage-to-ADU conversions started without checking zero-lot-line setback rules. Montclair’s narrow lots mean many detached garages sit right on the property line. If you start a conversion without confirming the setback, the city’s plan review will flag it and your timeline stretches by weeks while we redraw and resubmit.
- Builder-grade finishes replaced without a written scope of work and allowances. Homeowners in Montclair’s newer developments often jump into a kitchen or bath upgrade on a verbal agreement. Then the change orders start. We write the scope, the allowances, and the line items before any demolition begins.
- Builder warranties voided by modifying load-bearing walls or roof structure. If your home is still under a builder warranty, cutting into a load-bearing wall without the builder’s written approval can void that coverage. We coordinate with the builder’s warranty department before we touch structure.
- Older slab foundations and flat roofs showing drainage problems after winter rain. Montclair’s winter rain exposes low-slope roofs and slab foundations that were installed before modern drainage standards. We see pooling water and stucco damage every season, and we fix it before it turns into a structural problem.
Pricing for General Contractor in Montclair, CA
Here’s what you can expect to pay for the most common projects we do in Montclair. These are Montclair market numbers, calibrated to the city’s older housing stock and the cost of permits and inspections in the Inland Empire.
| Project | Typical Range in Montclair |
|---|---|
| Kitchen Remodel | $14,000 – $45,000 |
| Bathroom Remodel | $9,000 – $28,000 |
| ADU Construction | $90,000 – $220,000 |
| Garage Conversion | $30,000 – $80,000 |
| Home Addition | $45,000 – $130,000 |
What moves these numbers in Montclair? The age of your plumbing and electrical, whether we’re dealing with a zero-lot-line setback or shared wall, and the finishes you choose. KraftMaid cabinets cost more than stock options. Cambria countertops cost more than tile. But the labor is the same either way, and we write every estimate as a line item so you see exactly where the money goes. Call (855) 382-3257 for a free estimate with no obligation, and we’ll walk your property and give you a written range before you decide anything.
We Also Serve Cities Near Montclair
Our work in Montclair takes us across the San Bernardino County line into Claremont, Ontario, Upland, and La Verne on a regular basis. If you’re in one of those cities and facing the same landlocked-lot issues we see in Montclair, we’d be glad to take a look. Same team, same full-scope approach.
Serving Montclair, CA — Our Local Coverage Area
We’re based in the Montclair area and know this community well. Use the map below to see our service coverage — if you’re nearby, we can almost certainly help.
FAQs About General Contractor in Montclair
In most Montclair tract homes, the kitchen is the first place to start, with a realistic budget of $14,000 to $45,000 for a full remodel. Builder-grade cabinets are usually particleboard boxes with cheap hinges, and they start failing within five to seven years. Replacing them with KraftMaid or Wellborn cabinetry, and swapping the laminate countertops for Cambria or Caesarstone, immediately changes the feel of the house. The bathroom is usually second, at $9,000 to $28,000 depending on whether you’re replacing a vanity or gutting the room. Call (855) 382-3257 for a walkthrough of your specific house and an honest recommendation on what to do first.
The rule is simple: don’t cut into a load-bearing wall, alter the roof structure, or change the building envelope without written approval from the builder or, if the home is past that window, from the city plan-check desk. We coordinate with the builder’s warranty department before any structural work begins. Cosmetic upgrades like cabinets, countertops, flooring, and paint won’t affect the warranty. Moving a wall, enlarging a window opening, or adding a skylight might. We’ll tell you which category your project falls into before we start. For an exact quote, call (855) 382-3257.
Yes, if your Montclair home is in an HOA-governed development, you typically need architectural committee approval before pulling a city permit for a room addition, second-story build, or detached ADU. HOAs review things like setbacks, exterior finishes, roofline changes, and landscaping impacts. We prepare the drawings and materials list in the format HOAs expect, and we manage the submission. The city also has its own plan review, which runs in parallel. Skipping the HOA step can get a project stopped mid-construction. Call (855) 382-3257 and we’ll check what your specific HOA requires.
A realistic Montclair kitchen remodel runs $14,000 to $45,000. At the lower end, you’re looking at cabinet refacing or replacement with stock or semi-custom boxes, laminate or entry-level quartz countertops, and keeping the existing layout. In the middle, you’re replacing cabinets with KraftMaid, installing Silestone or Caesarstone countertops, adding a tile backsplash, and replacing fixtures with Kohler or Moen. At the upper end, we’re moving walls, replacing plumbing and electrical, adding an island, and installing premium appliances. The biggest cost drivers are whether we move plumbing and whether the wall we’re removing is load-bearing. For an exact line-item estimate, call (855) 382-3257.
Yes, and most Montclair detached garages are strong candidates because they already have their own footprint, roof, and often their own access from the alley or side yard. ADU construction in Montclair runs $90,000 to $220,000, and a garage conversion specifically lands between $30,000 and $80,000 depending on foundation condition, whether we’re adding a bathroom and kitchenette, and whether the garage sits on a zero lot line. The zero-lot-line issue is the most common complication we handle in Montclair, and we manage the extra plan review so it doesn’t stall your project. Call (855) 382-3257 and we’ll inspect your garage and tell you what’s possible.
Written by Norm Castellano, Owner at Toolbox Contractors, serving Montclair and the surrounding San Gabriel Valley.