Home Additions in Collingswood, NJ
More room without leaving the block you bought for. MAG Development designs, engineers and builds home additions across Collingswood — rear extensions, bump-outs, second stories and in-law suites — as one accountable scope from drawings through final inspection.
What a Home Addition Costs in Collingswood
Home additions in Collingswood generally run $250–$400 per square foot all-in — design, structural engineering, permits, construction and finishes. Where a specific project lands inside that band depends far more on what the addition contains than on how big it is.
A small bump-out of around 200 square feet typically runs $60,000–$95,000. A rear extension in the 400–500 square foot range, the most common Collingswood project, usually lands between $100,000 and $200,000. A full second story commonly runs $200,000–$450,000+, because it brings foundation evaluation, new stairs and a rebuilt roof with it.
Full figures and what sits behind them are in our home addition cost guide.
Types of Home Additions We Do in Collingswood
Rear Extension
Pushing the back of the house out to open a cramped kitchen into a real family room. On Collingswood’s long, narrow lots this is usually the most buildable direction and the best value per square foot.
Bump-Out Addition
A few feet gained off one room — a larger kitchen, a first-floor powder room, a mudroom off the back door. The entry point into our range and the least disruptive addition we build.
Second Story Addition
Bedrooms and baths added without touching the footprint, which matters when lot coverage is already at its limit. See the second story cost guide.
In-Law Suite Addition
A private bedroom, full bath and sitting area for a parent or an adult child, built to the same standard as the rest of the house rather than partitioned out of a basement.
Adding On to a Collingswood Home on a Narrow Lot
Collingswood was laid out and largely built between the 1890s and the 1930s, and the housing stock reflects it — Victorians, foursquares, Craftsman bungalows, twins and rowhomes on parcels that are narrow at the street and deep toward the rear. That geometry decides almost everything about an addition here. Side-yard setbacks rule out widening in most cases, so the practical directions are back or up.
The age of the houses decides the rest. Opening a wall in a Collingswood home reliably finds something: electrical service never sized for a modern kitchen, original framing that was not engineered to carry a second floor, knob-and-tube remnants, and foundations that need evaluation before anyone commits to building on top of them. None of that is a reason not to build — it is a reason to know before demolition rather than during it.
Lot coverage and impervious surface limits also come into play earlier here than in the townships, so we establish what the borough will allow at design, not after you have paid for drawings.
How a Collingswood Home Addition Works, Step by Step
Consultation
We walk the house, talk through what is not working, and give an honest read on what your lot and your budget actually allow.
Design & engineering
Drawings, structural calculations and a fixed scope — including how the addition ties into the existing roofline, foundation and systems.
Permits
We prepare and submit the borough package and manage review comments and inspections through to approval.
Build
One accountable crew, a published schedule, protected walkways on a tight street, and a walkthrough at completion.
Home Additions Near Collingswood
We build additions throughout Camden and Burlington County, and across the Main Line in Pennsylvania. If you are weighing a bathroom as part of the project, our Haddonfield bathroom remodeling page covers how those figures work, and homeowners comparing an attached suite should start with in-law suites in Moorestown. Explore the other towns we work in:
Collingswood Home Addition FAQ
How much does a home addition cost in Collingswood?
Most Collingswood additions run $250–$400 per square foot all-in. A bump-out of about 200 square feet typically runs $60,000–$95,000, a 400–500 square foot rear extension $100,000–$200,000, and a full second story $200,000–$450,000+. Our cost guide breaks it down by size and type.
Can I add on if my Collingswood lot is narrow?
Usually, yes — but the direction matters. Side-yard setbacks make widening impractical on most Collingswood parcels, so the realistic options are extending toward the rear or building up. We establish what the borough allows during design, before you commit to a scope.
How long does a home addition take in Collingswood?
Plan on three to four months of design, engineering and borough approval before construction starts, then three to eight months of building depending on scope. A second story sits at the longer end of that range.
Can we stay in the house during construction?
Usually yes for a rear extension or bump-out, since most of the work happens outside the existing envelope until tie-in. A second story generally means moving out for part of the build once the roof is opened.
Will the addition look like it was always there?
That is the standard we build to. Matching siding, brick coursing, window proportions and rooflines is what separates an addition that reads as original from one that looks bolted on — and on Collingswood’s close-set blocks the difference is very visible from the street.
Do you handle the architect and engineer, or do I hire them?
We handle it. MAG is design-build, so architecture, structural engineering, permitting and construction sit with one accountable team rather than three companies pointing at each other.