For most Weymouth homeowners, adding on costs less than trading up. US ProPaint & Renovation builds room additions, second-story additions and master suites across Weymouth, and the math usually favours staying — selling and rebuying runs about $35,000 to $43,000 in transaction costs before you buy a single extra square foot.
By JR Reis, Owner & President · Last updated October 2026
Usually, yes — and the gap is wider than people expect, because moving costs are front-loaded and invisible until you’re in them.
Weymouth’s median sale price has been running around $630,000 through 2026, at roughly $411 per square foot. Here’s what it costs just to get out of your current house:
| What you spend to move | Typical Weymouth range (2026) |
|---|---|
| Broker commission on the sale (~5%, negotiable) | $29,000 – $33,000 |
| Massachusetts deed excise ($4.56 per $1,000) | ~$2,900 |
| Attorney, recording and closing fees | $1,200 – $2,000 |
| Local move, 3–4 bedroom household | $2,000 – $5,000 |
| Cost to exit, before buying anything | $35,000 – $43,000 |
Market ranges, not quotes. Your numbers depend on your sale price, your agent agreement and your mortgage balance.
Now add the purchase side. Buying 400 more square feet of Weymouth house at the town’s median price per square foot costs roughly $165,000 more — and you reset your mortgage at whatever rate is on offer the day you close.
A 400-square-foot addition in this market runs $60,000 to $160,000 depending on type, foundation work and finish level. You keep your rate, your street, your schools and your commute. That’s the whole argument, and it holds for most of the capes and ranches across North, South and East Weymouth.
Where moving wins: when you need a fundamentally different house — a flatter lot, a first-floor layout your current structure can’t accommodate, or a different school district. An addition makes a good house bigger. It can’t make a bad fit right.
This is where the conversation gets specific, and it’s the part most homeowners haven’t looked into before they call us.
Most of Weymouth is zoned R-1 Low-Density Residential. On paper, R-1 asks for a 25,000-square-foot lot, 120 feet of lot width, an 18-foot front yard, 10-foot side yards and a rear yard of 24 feet or one-fifth of the lot depth, with a height cap of two and a half stories. (Schedule of District Regulations)
Here’s the catch: the vast majority of Weymouth’s single-family lots were laid out long before those numbers existed, and they’re nowhere near 25,000 square feet. That makes them pre-existing nonconforming — legal, buildable, but subject to Article XIII, Section 120-40 of the zoning ordinance the moment you want to extend the structure. If your addition pushes further into an already-deficient setback, you’re applying to the Board of Zoning Appeals, and the burden sits on you to prove the original structure was lawful when it was built.
The second constraint catches people more often than setbacks do. R-1 caps lot coverage at 30%, and in Weymouth that calculation includes every impervious surface — driveway, patio, shed, pool, walkways. Plenty of homeowners assume they have room for a 500-square-foot family room and discover the paved driveway already ate most of the allowance. We run that number before anything gets drawn, because it decides the whole shape of the project.
Three other things we check early on a Weymouth site:
Once we know what the lot allows, the choice usually narrows to one of three.
Build out when coverage and setbacks leave you room. It’s the cheapest path per square foot because the structure is simple and the existing roof stays mostly intact.
Build up when the lot says no. A second-story addition adds square footage without touching lot coverage at all, which is often the only route on a tight Weymouth parcel. The trade-off is structural: on a 1950s cape or ranch, we’re checking whether the existing foundation, footings and wall framing can carry a second floor before anything else is decided. Sometimes they can. Sometimes the first real cost of the project is underneath the house, not on top of it.
Build an ADU when the goal is a self-contained unit for a parent, an adult child or rental income. Since February 2, 2025, the Affordable Homes Act allows one accessory dwelling unit of up to 900 square feet by right in every single-family zoning district in Massachusetts — no special permit, no zoning board hearing. (Mass.gov ADU guidance) That’s a genuinely different permitting path from an addition that needs zoning relief, and it’s worth knowing before you commit to a design.
There’s a fourth option people overlook entirely: finishing the basement. It adds no footprint, triggers no coverage calculation, and costs less per square foot than anything you build new.
A straightforward, fully compliant addition runs roughly four to seven months from first measurement to final inspection. Here’s where the time actually goes:
If you need zoning relief, add at least ten weeks. The Town is explicit about this: Board of Zoning Appeals applications typically need to be filed four weeks before the desired meeting date, abutters must be notified and the hearing legally advertised 14 days out, the Board has to open, close and vote in public, the written decision gets signed at a later meeting, and then there’s a 20-day appeals period before the decision can be recorded at the Norfolk County Registry of Deeds. Weymouth’s own guidance puts a typical BZA case at two to three months.
Nobody enjoys hearing that. But a schedule that ignores it isn’t a schedule — it’s a sales pitch, and you’ll find out in month three.
Winter matters too. Footings go below frost depth, and a foundation pour scheduled for January on the South Shore is a conversation about temporary heat and blankets, not a given.
We’re headquartered at 175 Derby Street in Hingham, a few minutes from the Weymouth line — close enough that our crews are on South Shore sites daily rather than driving in from Boston.
Around Weymouth we regularly work in North Weymouth, South Weymouth and Columbian Square, East Weymouth, and Weymouth Landing, plus the neighbouring towns: Braintree, Quincy, Hingham and Rockland. For the full range of work we do in town, see our Weymouth services page.
One thing homeowners tell us repeatedly: the structural work is what separates contractors. A Weymouth-area client who hired us to replace a rear deck noted that the job included recasting new foundation piers rather than reusing what was there — that’s the same instinct that governs how we approach an addition. What’s underneath decides how long what’s on top lasts.
We carry Massachusetts Home Improvement Contractor registration #186517, manage the permit process with the Town of Weymouth on your behalf, and back addition work with a two-year workmanship warranty.
What does an addition cost per square foot around Weymouth?
Additions in this market generally run $150 to $400+ per square foot, so a 400-square-foot addition lands between $60,000 and $160,000. Type, foundation requirements and finish level drive the range. Our home additions service page breaks down what moves the number.
How long does an addition take from design to finish?
Four to seven months for a compliant addition — roughly six weeks of design and drawings, two to four weeks of permitting, and ten to twenty weeks of construction. Add at least ten more weeks if the project needs Board of Zoning Appeals relief.
Is an addition cheaper than moving house?
In Weymouth, usually. Selling and moving costs $35,000 to $43,000 in commission, deed excise, closing fees and movers before you buy anything — and buying 400 more square feet at local prices adds roughly $165,000, plus a new mortgage rate. The addition keeps your rate and your street.
Can you live in the home while an addition is built?
In most cases, yes. We seal the work area off from the rest of the house and keep the existing structure weathertight until the tie-in. The disruptive stretches are the foundation work and the day we open the wall or roof. If the addition includes your only kitchen or bathroom, we’ll flag that in planning so you can decide.
What limits an addition on a tight Weymouth lot?
Three things, in this order: the 30% lot coverage cap in R-1 — which counts your driveway, patio, shed and pool — then setbacks on a lot that’s probably already nonconforming, then height. When those rule out building outward, a second-story addition or a finished basement is usually the answer.
US ProPaint & Renovation
Adress:175 Derby St STE 4 Hingham, MA 02043
Phone: (617) 922-6305
Toll Free: (800) 964-0717
Email: office@uspropaint.com
Serving Weymouth and the surrounding South Shore, including North Weymouth, South Weymouth, East Weymouth, Weymouth Landing, Braintree, Quincy, Hingham and Rockland.
