A Benson company - serving San Francisco, CA
A new rear addition with a vaulted beamed ceiling and tall windows
Home Addition Contractor · Piedmont, CA

Home Addition Contractor in Piedmont - Design, Permits and Build Under One Contract

We handle the design, the engineering, and the city permit, then build it. One contract, one crew, one accountable point of contact. Free feasibility check on your lot before you commit.

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Licensed & Insured Written Quotes Free Estimates All Brands Satisfaction Guarantee
Free Estimate on SiteCalls Answered by a Live Person, 24/7Background-Checked TechniciansA Local Team in San Francisco
A single-story rear room addition with tall windows and a new patio
A new sunroom addition with three walls of windows
A new two-story ADU over a garage
A compact kitchen inside a new ADU
A new modern ADU with wood cladding
The bedroom inside a new ADU
The bathroom inside a new ADU
A small deck outside a new ADU
Every project starts with

A free site visit, a check of what your lot allows and a written, line-item price.

Get your free estimate

Fast, Reliable Home Addition Contractor Across Piedmont

Adding space to a Piedmont home means working within some of the strictest design rules in the East Bay. You need a contractor who knows Piedmont’s historic zoning and review process before the first plan is drawn. We handle complete home additions across the city, from sunroom additions on Wildwood Avenue to second-story additions on Crocker Avenue, and we put every price in writing before work begins. Troubled by scope creep? No. On a standard second-story addition in Piedmont, you’re looking at $275,000 to $450,000, and a sunroom runs $180,000 to $340,000. We explain what drives those numbers line by line, then stick to the quote. Call (424) 328-5746 for a free site walk.

Call (424) 328-5746

Why Benson ADU San Francisco Is Piedmont’s Preferred Home Addition Contractor Company

A second-story addition that matches the existing roofline

Piedmont homeowners call us because we show up knowing the difference between what builds fast and what builds through the city’s design review without a fight. The team at Benson ADU San Francisco works directly with Piedmont’s planning department on a regular basis, so we know that a roof pitch between 6:12 and 12:12 is a hard requirement, not a stylistic suggestion. Troy Eastman, who leads our crews, walks every Piedmont site before quoting. He checks the slope, the staging access, and the neighbor’s wall line. That upfront work is why our written quotes hold.

We’re part of the Relay Home Co. family, founded in 2006, and Piedmont jobs carry the same two guarantees we offer everywhere: a written price before demolition starts and a 365-Day Done Right Promise. If a drain leaks, a door binds, or a seam opens within a full year, we come back and make it right. You also get a free second visit if any covered repair fails. That’s not a verbal commitment. It’s stamped on your project paperwork.

Every technician who walks onto your Piedmont property is background-checked and in uniform. You know the name, the face, and the reason they’re there. And when you call our office, a live person answers. Always. No voicemail tag, no “we’ll call you back Monday.” That matters when you’re coordinating a crane on a steep lot or need an answer before a city inspection.

Sunroom Addition in Piedmont

A sunroom addition in Piedmont is rarely a bolt-on glass box. It’s a carefully reviewed room that must look like it has always been part of the house. That’s the thing that surprises people moving here from Oakland or Berkeley. We design sunrooms here with the same eave depth, window trim profile, and roofline as the existing Craftsman or Tudor structure. Get it wrong, and the design review board sends you back to the drawing board. We get it right the first time.

What a Piedmont Sunroom Builds With

We spec sunrooms for Piedmont’s damp, foggy mornings. That means proper flashing, a sloped foundation drainage path, and glazing selected for morning condensation. On clay hillside lots, we typically include a foundation and moisture package that runs $12,000 to $28,000 depending on the slope. A flat-grade sunroom on Crocker Avenue will land at the lower end of the $180,000 to $340,000 range. A hillside lot on Wildwood with existing drainage issues runs higher.

Matching the Original House

Piedmont’s review standards mean your sunroom’s siding, window style, and roof pitch get compared against the original house. We’ve done matching shingle work near the Crocker Avenue corridor and stucco-matched additions on streets with Spanish Colonial Revival homes. The goal: when the room is finished, a neighbor walking by should not be able to tell where the old house ended and the addition began. That’s the standard here, and we build to it.

Second Story Addition Contractor in Piedmont

A second-story addition with a balcony, matched to the original house

A second-story addition in Piedmont solves the most common problem in this city: you have a beautiful old home, a growing family, and a lot too small to expand outward. But going up here is not like adding a bedroom in a newer suburb. The design review process looks at how the added mass affects the street-facing character, and the engineering has to account for hundred-year-old foundations. We’re a second-story addition contractor that plans both sides before a single permit is pulled, pairing the expansion with seismic upgrades and foundation reinforcement when needed. Expect $275,000 to $450,000 for a full second-story addition in Piedmont, depending on square footage and what the existing foundation requires.

Engineering an Older Foundation

Piedmont homes from the 1910s and 1920s often sit on unreinforced brick or shallow concrete footings. We don’t frame a second story on top of a foundation that can’t carry it. On a typical Tudor off Crocker Avenue, we added steel moment frames and a new perimeter footing before the upper framing went up. The structural package ran $35,000 to $70,000. It’s a cost no honest contractor should hide, and we show it as its own line item.

Staging a Second Story Uphill

Many Piedmont second-story jobs are on upslope lots where a truck can’t reach the back wall. We plan material delivery around that. A tracked lift or, on the steepest Crocker Avenue lots, a crane is booked in advance. We stage lumber and panels on the front setback, keep the street clear at the end of each day, and coordinate with neighbors before we block a lane. Access planning is built into your written quote, not added later as a surprise.

Trusted Brands We Service in Piedmont

We’re authorized to build with brands Piedmont homeowners can research themselves. For second-story additions, we use James Hardie fiber-cement siding and trim, which holds up to the marine-influenced mist that rolls through the hills each morning. For a project that benefits from prefabrication, we can build with Abodu or Cover panels, which tighten the on-site schedule and reduce the number of days our crew occupies your narrow street. We stock common James Hardie profiles locally for Piedmont jobs, so trim replacements and small repair callbacks don’t wait on a freight truck from the East Coast. Fast turnaround, and the warranty is honored in full.

Common Home Addition Contractor Problems We See in Piedmont Homes

  • Demolition started before a party-wall notice was posted. On a zero-lot-line street, your addition might share a wall with the house next door. Piedmont requires written notice before any cutting begins. Skipping that step stalls the permit and sours the neighbor relationship for the rest of the build.
  • Underquoted access on steep lots. A sunny second-story plan dies the day you find out a crane is $12,000 because the backyard can’t be reached by a truck. We quote access honestly, line by line, before you commit.
  • A flat-roof sunroom proposed to speed things up. Piedmont rejects flat-roof accessory structures in historic districts. The city requires roof pitches between 6:12 and 12:12 to match the surrounding architecture. We’ve seen homeowners lose months to that mistake.
  • Foundation work billed as an “unexpected condition.” On a hundred-year-old Piedmont hillside home, a weak foundation is not unexpected. It’s the norm. We include a structural allowance in your written quote so the price doesn’t jump mid-project.

Pricing for Home Addition Contractor in Piedmont, CA

Here’s the honest range for Piedmont’s market. A sunroom addition runs $180,000 to $340,000. A second-story addition runs $275,000 to $450,000. A ground-level room addition, like a garage conversion to living space, runs $120,000 to $220,000, depending on foundation and utility work. What moves the number: the slope of your lot, whether the existing foundation needs seismic reinforcement, the roof pitch demanded by design review, and how the materials get staged. On Crocker Avenue, access alone can add $10,000 to $20,000 to a second-story job. Every quote we give includes that math, written out, in advance. Call (424) 328-5746 for a free written estimate on your Piedmont addition.

We Also Serve Cities Near Piedmont

Our Home Addition Contractor team works throughout the inner East Bay. In addition to Home Addition Contractor in Piedmont, we serve homeowners in Berkeley, Albany, Lafayette, and San Francisco. If you’re in one of those cities and planning a room addition, a sunroom, or a second-story build, the same written pricing and 365-Day Done Right Promise applies.

Serving Piedmont, CA - Our Local Coverage Area

We’re based in the Piedmont 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 Home Addition Contractor in Piedmont

Why Piedmont Chooses Benson ADU San Francisco

We set the standard for home addition contractor in Piedmont.

No Change-Order Surprises

The written quote you sign is the price you pay. Anything we find mid-job gets priced and approved by you in writing before we touch it.

Licensed & Insured

Fully certified technicians who meet all local and state licensing requirements.

Upfront Pricing

No hidden fees, no surprises. You approve the price before any work begins.

Guaranteed Work

Every repair and installation is backed by our workmanship warranty and satisfaction guarantee.

How It Works in Piedmont

Getting your home addition contractor handled is simple and fast.

1

Call or Request a Free Estimate

Tell us about your home addition contractor needs and we provide an upfront, transparent quote - no obligation, no hidden fees.

2

Licensed Technician Dispatched

A background-checked, certified technician arrives in Piedmont - typically within 30-60 minutes, with parts stocked on the truck.

3

Problem Solved, Guaranteed

We complete the job to your full satisfaction, backed by our warranty and 100% satisfaction guarantee.

What happens when you call

  1. 1
    A real person answersNo phone trees - talk to a local home addition contractor pro.
  2. 2
    You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
  3. 3
    We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
  4. 4
    You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.

What Piedmont Customers Say

Trusted by homeowners across Piedmont and surrounding areas.

★★★★★

"Booked a consult online and met the project manager two days later. Weekly progress updates arrived by text with photos. ADU finished on schedule."

Hannah W. · Verified customer
★★★★★

"Great build. Inspection delay, the county's fault, pushed things a week, but updates were clear."

Soo-jin P. · Verified customer
★★★★★

"Garage conversion into a guest suite. I could see the permit status in the app, which made it painless."

Rick F. · Verified customer

More ADU services in Piedmont

Every build below starts the same way: a free site visit and a written price.

Getting started with Benson in San Francisco

Every project starts with a conversation and a written price. Here is how to take the first step.

A project lead measuring a backyard ADU site with the homeowner

Free site visit

A project lead walks the lot with you, checks what it allows and hands you a written, line-item price. No obligation.

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A building crew carrying lumber to a backyard ADU site

Your San Francisco team

A local crew that works across San Francisco and the towns around it, to the same written standard as every Benson location.

Areas we serve
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Read our written promise

What we promise on every job, written down, with the terms spelled out before any work starts.

Our promise

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(424) 328-5746

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