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Foundation Repair and Basement Waterproofing in Chelmsford, MA
Heavy rain in 2024 pushed Chelmsford's sewer flow past its permitted level, and the town answered with a pilot program to get sump pumps out of the sewer. Call (978) 800-2819 or use the form. A person reads every request and replies with what happens next.
- Free for homeowners
- Town and state rules on this page
- North Chelmsford to the Center
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Basements in Chelmsford
What's going on downstairs?
Waterproofing & Drainage
Wet walls, seepage at the floor joint and spring water in the basement, handled with interior drains, exterior work or both.
Sump Pumps
New pits, replacement pumps and battery backups, with the discharge going somewhere your town allows.
Foundation Cracks & Repair
Leaking cracks, bowing or settling walls and failing mortar in old fieldstone, with an engineer brought in when the job is structural.
Crawl Spaces & Finishing
Damp crawl spaces sealed up, and dry basements turned into finished space with the right permits.
Not sure what it needs?
(978) 800-2819Tell us where the water comes in and how often the sump runs, and we'll help you figure out the job.
Permits
Permits and rules for basement work in Chelmsford
The Chelmsford Building Department is at 50 Billerica Road. Its FAQ says any structural change, windows, doors, siding or opening of walls needs a building permit, while painting, flooring, carpeting and cabinets without structural changes don't (Building FAQs). A new egress window cut through a foundation wall fits that description. Building, plumbing and other permits are filed online through PermitEyes (Procedures for Obtaining a Permit).
- Building Department
- 50 Billerica Road, 978-250-5225
- File online
- PermitEyes
- Residential building permit
- $150 minimum, plus $15 per $1,000 above $10,000 (as posted November 2026)
- Foundation-only permit
- $15 per $1,000
- Plumbing and gas
- $75 first fixture, $6 each additional; sewer-related work $50
- Reinspection
- $100 when charged
- Sewer
- Foundation drains and downspouts barred; connection limits since November 1, 2022
Fees. The town's fee page lists a $150 minimum for a residential building permit, plus $15 per $1,000 of cost above $10,000, $15 per $1,000 for a foundation-only permit, and a $100 reinspection fee that may be charged for missed appointments or work that needs extra inspections. The page shows no effective date (Permit Fees). A sump discharge line or ejector is plumbing work under a separate permit.
Finishing the basement. State code requires at least 6 feet 8 inches of ceiling height for habitable basement rooms, photoelectric smoke alarms, and a carbon monoxide alarm on every level including the basement; a single- or double-hung escape window needs a 3.3 square foot net clear opening under the state amendment (780 CMR chapter 3). The state's guidance chart marks structural carpentry, insulation and wallboard as permitted work (state HIC chart).
Hiring. A contractor improving an owner-occupied home of one to four units generally has to be registered as a Home Improvement Contractor; look them up on the Contractor Hub. A licensed construction supervisor or registered design professional oversees construction on one- and two-family homes (construction supervisor rules). Contracts over $1,000 must be in writing, and you have three business days to cancel one signed at home (M.G.L. c.142A §2). No state rule requires an engineer for residential foundation repair, but the building official can ask for more construction documents and requires sealed documents in a flood hazard area (780 CMR R107.1 and R322.1). Exterior excavation needs a Dig Safe notice at least 72 hours ahead, weekends and holidays excluded (M.G.L. c.82 §40A).
Last verified November 2026. Fees, restrictions and deadlines on this page are due for re-checking by May 2027. New England Basement Pros is a referral service. We don't pull permits or do basement work; the contractor files the permit.
Water
Where the water comes from in Chelmsford
Not into the sewer. Section 4.8 of the Sewer Use Regulations, revised June 27, 2011, bars connecting roof downspouts, foundation drains, areaway drains or other surface runoff and groundwater sources to a building sewer or drain connected to the public sewer. Stormwater and unpolluted drainage go to storm sewers or an approved natural outlet, town staff may enter private property to inspect, and a violation that continues after notice is a misdemeanor with fines up to $5,000, each day a separate offense (Sewer Use Regulations). The town's illicit discharge rules define what may reach a street drain; ask the DPW before a contractor routes a sump line toward one.
The 2024 rains. The 2024 Annual Town Report says above-average rainfall caused unprecedented drainage problems across town, and that sewer flow exceeded its permitted level. The town responded with a sewer capacity credit transfer policy and a pilot program to give residents an incentive to disconnect sump pumps, and the Finance Committee recommended money for an infiltration and inflow study (2024 Annual Town Report). The report doesn't give the incentive amount; ask the DPW whether the pilot is open.
Sewer connection limits. The Sewer Capacity and Connection Restriction, in effect since November 1, 2022 and last updated September 14, 2026, allows no new connections or added capacity for properties that change or expand, keeps detached accessory units off the sewer, and lets the DPW require seven days of flow monitoring that includes a wet period (connection restriction).
Groundwater and sand. The 2010 Open Space and Recreation Plan says excessively drained sandy soils made septic systems the norm for single-family homes, and that sewer service made some lots encumbered by high groundwater buildable. It notes floodplain along the Merrimack River at Southwell Park and along River Meadow Brook, says FEMA's updated flood maps took effect July 1, 2010, and cites the 2007 Mother's Day and Patriot's Day storms and localized flooding from heavy spring rain in 2010 (2010 Open Space and Recreation Plan). Look up your address on FEMA's Flood Map Service Center.
Floodplain and wetland limits. The Floodplain Overlay District, adopted in 1977, covers the 100-year floodplain on the current flood maps, and new construction in it needs a special permit and an engineer's certification that it won't raise flood levels (Master Plan, October 2021). The local Wetlands Bylaw sets a 100-foot buffer zone and a 200-foot riverfront area, bars impervious surfaces within 30 feet of a resource area, and bars building within 50 feet on lots of 40,000 square feet or more (Wetlands Bylaw). Its regulations, effective September 15, 2015, allow no grading, filling, excavation or vegetation removal within 25 feet (Wetlands Bylaw Regulations). An exterior drain or regrading job near Stony Brook, the rivers or a pond starts with the Conservation Commission.
Chelmsford's homes
A 1960s and '70s suburb around an 18th-century center
The 2010 open space plan says Chelmsford's population grew in the 1960s after I-495 opened, and that single-family home building peaked in the 1960s and '70s; the Town Center historic district has homes going back to the 18th century (2010 Open Space and Recreation Plan). About 68% of homes are detached single-family houses (2025 Open Space and Recreation Plan).
The Chelmsford Center Historic District is overseen by the Historic District Commission under state law. The bylaw exempts paint color, roof material color, storm doors and windows, screens and in-kind rebuilding after a disaster, but doesn't mention window wells or bulkheads (Historic District bylaw), so ask the commission before changing the outside of a house there.
Radon
Testing a Chelmsford basement for radon
The state's town-by-town radon dashboard didn't load for us, so we have no Chelmsford number. New one- and two-family homes in Middlesex County, as in Essex and Worcester, must include a passive radon mitigation system, and the state says no area of Massachusetts is free of risk (radon tracking). In guidance we checked in November 2026, the state health department says to test at the lowest livable level between November 1 and March 31, strongly recommends mitigation at 4.0 pCi/L and says to consider it from 2.0 to 4.0 (testing your home for radon).
FAQ
Chelmsford basement questions
Can a foundation drain go into the sewer in Chelmsford?
No. The town's Sewer Use Regulations, revised June 27, 2011, bar connecting roof downspouts, foundation drains or areaway drains to a building sewer that reaches the public sewer, and send stormwater and unpolluted drainage to storm sewers or approved natural outlets. A violation that continues after notice can bring a fine of up to $5,000, with each day a separate offense.
Is there help for moving a sump pump off the sewer?
The 2024 Annual Town Report says the town started a pilot program to give homeowners an incentive to disconnect sump pumps. It doesn't give the amount or say how to sign up, so ask the DPW whether the pilot is still running.
Does the sewer connection restriction affect basement work?
It limits new sewer connections and added capacity for properties that change or expand. The restriction took effect November 1, 2022 and was last updated September 14, 2026; it doesn't mention sump pumps. If a basement project adds a bathroom or a unit, check with the DPW early.
How close to a wetland can a contractor dig?
Chelmsford's wetland regulations allow no grading, filling, excavation or vegetation removal within 25 feet of a resource area, and the bylaw bars impervious surfaces within 30 feet. Work within 100 feet goes to the Conservation Commission.
What does it cost me to use New England Basement Pros?
Nothing. Asking is free for homeowners; the contractor prices the job, and the price and contract are between you and them.
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