Will the addition look like it was always there?

That’s the goal, and it comes down to three things: matching the roofline pitch, sourcing siding and trim that match (or re-siding the affected elevation), and framing square so the transition line is clean. Because framing is our specialty, the structural tie-in is the part we get right first.

Can I live in the house during the addition?

Usually yes. We seal the work zone from the living space, protect floors and pathways, and stage the opening between old and new so the house stays weather-tight. There are a few noisy days — demo and framing — that we schedule with you.

Do I need an architect for an addition in Cambridge?

For most straightforward additions we can work from a builder’s plan set. Architect or engineer involvement is typically needed for larger structural changes, second stories, or when your town’s zoning review requires stamped drawings. We tell you up front which path your project needs.

Is an addition worth it compared with moving?

That depends on your neighborhood and how long you plan to stay. An addition makes sense when you like your location and lot and the existing house is structurally sound. It makes less sense when you would be building well past the ceiling of what homes in that neighborhood sell for. We would rather walk through that math with you honestly than sell you a project you regret.

How long does a home addition take from start to finish?

Plan on four to eight months for a typical addition. Design and engineering take four to eight weeks, permitting and any zoning review another two to twelve weeks depending on the town, and construction three to five months. The permitting stage varies the most, because it depends on your local board's schedule rather than on the work itself.

Will I need zoning relief or a variance?

You will if the addition encroaches on a required setback, exceeds lot coverage, or sits on a non-conforming lot — which is common with older New England homes on small parcels. Zoning relief means a hearing before the Zoning Board of Appeals and adds weeks to months. We check your lot against the local dimensional requirements before design, so this surfaces early rather than after you have paid for drawings.

How much does home additions cost in Cambridge, MA?

Home Additions pricing in Cambridge depends on the size, scope, materials, and structural complexity of your specific project. RS Development Group provides a free, written, itemized estimate after an on-site walkthrough — call (774) 512-3176 to schedule.

Do you offer home additions near me in Cambridge?

Yes. RS Development Group provides home additions throughout Cambridge, the rest of Middlesex County, and the surrounding Greater Boston area of Massachusetts. We’re a licensed, insured contractor (MA HIC #216507) based in Marlborough, MA.

What areas near Cambridge do you cover?

Beyond Cambridge, we regularly work throughout the Greater Boston area of Middlesex County — including Franklin, Bellingham, Somerville. Call (774) 512-3176 and we’ll confirm we cover your street.

Are you licensed and insured for home additions in Cambridge?

Yes — fully licensed (MA HIC #216507) with general liability and workers’ compensation insurance. We pull all permits and build to code on every Cambridge project.

How soon can you start my Cambridge home additions project?

Typical timeline is 1-2 weeks from estimate to site visit, then 2-6 weeks to start depending on the permit timeline. For emergency repairs we offer same-day or next-day response across the Greater Boston area. Call (774) 512-3176.

Home Additions · Cambridge, MA

Home Additions in Cambridge, MA

RS Development Group designs and builds room and second-story additions for Cambridge, MA homeowners. We bring home additions to Cambridge homeowners across Middlesex County's Greater Boston area, including nearby Franklin. Licensed & insured (MA HIC #216507) and serving the Greater Boston area. Call (774) 512-3176 for your Cambridge estimate.

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Local Expertise

Home Additions Challenges in Cambridge

Real problems Cambridge homeowners face — and exactly how RS Development Group solves them.

The problem

Multi-generational Cambridge households need private, code-legal in-law space, not just an extra room.

Our solution

We design and build in-law suites and ADUs with proper egress, utilities, and separation, built to code.

The problem

Existing Cambridge homes often can't carry a second story without reinforcement — a fact cheaper builders ignore.

Our solution

We trace the load path to the foundation and reinforce it first, so the addition is safe for generations.

The problem

Cambridge homeowners worry an addition will be a disruptive, never-ending project.

Our solution

We give you a clear schedule up front, manage every trade, and keep you informed from foundation to final walkthrough.

Professional Home Additions for Cambridge Homes

A home addition is one of the smartest investments a Massachusetts homeowner can make — more living space, higher property value, and no need to leave the neighborhood you love. RS Development Group designs and builds additions from the foundation and framing up: room additions, second-story additions, in-law suites (ADUs), garage conversions, sunrooms, and bump-outs. Because structural framing is our specialty, we tie new space into your existing home so it is square, solid, and looks like it was always there.

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What You Get in Cambridge

Room, second-story, in-law suite (ADU) & bump-out additions
Seamless tie-in to your existing home — matched rooflines, siding & trim
Engineered framing built to code (780 CMR), permits handled for you
Adds living space and home value without the cost of moving
Foundation, framing, and finish coordinated under one contractor
Fast response across the Greater Boston area, from our Marlborough base

What We Install for Home Additions in Cambridge

Full foundation or frost-wallPoured foundation, crawlspace or slab depending on the addition type and site.
Matched roofing & sidingWe source materials to match your existing roof, siding and trim so the addition doesn’t read as an add-on.
Engineered framingLVL/PSL headers and beams to carry the new load and open the connection to the existing home.
Code-compliant egressWindows and doors sized for egress in any new bedroom or in-law space.

Code & Permits in Cambridge, MA

Zoning review first — setbacks, lot coverage and height limits vary by town and can reshape the design.
Building permit plus separate electrical, plumbing and mechanical permits, all coordinated by us.
Existing structure evaluated to confirm it can carry the new load before we build up.
Historic-district review handled where applicable.

What Drives Home Additions Cost in Cambridge

We don’t quote home additions over the phone, because these are the factors that actually change the number on a Cambridge project:

Building out (new foundation) vs building up (structural reinforcement)
Whether the addition includes a kitchen or bathroom
Roofline complexity and how it ties into the existing roof
Finish level — flooring, cabinetry, fixtures
Zoning and permit timeline in your town

How Long It Takes

Most residential additions run 2–4 months from permit issue to final walkthrough, with design and permitting adding several weeks before that.

Every Cambridge estimate is free, written and itemised after an on-site walkthrough — so you see exactly what you’re paying for.

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How It Works

Our Home Additions Process

Simple, transparent, and stress-free from first call to final walkthrough.

Free Consultation

Call us or fill out our form. We’ll discuss your project needs and schedule a site visit at your convenience.

Detailed Estimate

We provide a comprehensive written estimate with transparent pricing. No hidden fees, no surprises.

Expert Construction

Our skilled team executes your project with precision, keeping you informed every step of the way.

Final Walkthrough

We walk through the completed project together, ensuring everything meets your expectations.

Portfolio

Recent Home Additions Projects

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Answers

Home Additions in Cambridge — FAQ

Not automatically — the foundation, walls and existing framing have to carry the new load. We evaluate the full load path down to the footings before designing, and reinforce where needed. Builders who skip this step are why some second-story additions crack and sag.

Testimonials

What Cambridge Homeowners Say

5 out of 5 from 27 reviews on our Google Business Profile.

“This company is amazing, affordable highly recommend them!”

— Noady SaldanhaMay 2025

“Roger and his team are professional, thorough, and very hardworking. They finished the job on time with quality craftsmanship.”

— Matt SmithJuly 2026

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Permitting & Code in Cambridge

Cambridge Building Department

Inspectional Services Department

831 Massachusetts Ave., 1st Floor, Cambridge, MA 02139
(617) 349-6100
Online permit portal

Verified 2026-07-20 · RS Development Group pulls permits on your behalf.

Design ground snow load in Cambridge

40 psf

At 40 psf this is the middle band for Massachusetts, lighter than the hill towns to the west and north. It is the starting point for sizing rafters, ceiling joists, and headers on any roof or addition here — the code requires the design roof load to be the greater of the value calculated from this figure or the minimum listed for the town, so we run the numbers for your specific structure rather than working from the table alone.

Source: 780 CMR 51.00 Table 301.2(2) · checked 2026-07-20

Permit fee in Cambridge: $15 per $1,000 of construction cost or fraction thereof for three residential dwelling units or fewer; minimum fee $50 (source)

Cambridge has a local historic district

If your home falls inside it, exterior changes — siding, windows, roofing material, additions visible from the street — need Historic District Commission review before the building permit issues. That review adds time, so we file it early rather than discovering it mid-project. Commission details.

Rogerio Alves

Founder & Lead Contractor

Call (774) 512-3176

About RS Development Group

A Marlborough Contractor Built on Structural Expertise

Founded in 2008 by Rogerio Alves, RS Development Group has grown from a specialist framing crew into a full-service general contractor serving 109 cities and towns across Massachusetts. We're proud to bring that same craftsmanship to Cambridge and the Greater Boston area.

What sets us apart is where we started: structural framing. Because we understand how a home is built from the skeleton out, every roof, addition, deck, siding job, and remodel we take on is handled with a structural awareness most contractors simply don’t have — which means fewer surprises, cleaner tie-ins, and work that lasts.

We’re fully licensed (MA HIC #216507) and insured, and we back every job with honest, written pricing and a schedule we keep. That’s how we’ve earned a perfect 5-star rating from 27 homeowners across the region.

Fully licensed — MA HIC #216507
General liability & workers’ compensation insured
Family-owned and operated since 2008
Perfect 5-star rating across 27 verified reviews
Free, written, itemized estimates — no surprises
Every project built to code and finished on schedule

Since 2008

Serving Massachusetts

5★

27 Verified Reviews

109

Massachusetts Cities & Towns Served

Licensed

MA HIC #216507

Other Services in Cambridge

Framing Services General Contractor Deck Construction Home Remodeling Siding Installation Roofing Services

Home Additions Near Cambridge

Norwood, MA Franklin, MA Bellingham, MA Somerville, MA Medford, MA Malden, MA

Get Your Free Home Additions Estimate in Cambridge

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