Home Addition Contractors NJ: The Homeowner's 2026 Hiring Guide (Mercer County)

How to Hire a Home Addition Contractor in NJ in 2026#

Hiring a home addition contractor in NJ requires more than a Google search and a license check. A home addition is fundamentally different from a kitchen or bath remodel — you are physically adding square footage to your house, which means new foundations, new framing, new roof tie-ins, new mechanicals, and structural load paths that have to be engineered and inspected. Most homeowners only learn this after they have signed a contract with the wrong contractor. This guide is the conversation we have with every homeowner at the kitchen table before they hire anyone — us or someone else.

We are The 5th Wall LLC, a father-son contractor team based in Lawrence NJ (Stefanos and Tony Karpontinis). We are NJ HIC-registered, carry $2 million in liability insurance, and build additions across all 10 Mercer County towns — Lawrence, Princeton, Hamilton, Ewing, Trenton, Lawrenceville, Pennington, Robbinsville, West Windsor, and Hopewell. This guide is based on what we have actually seen go right and go wrong on NJ addition projects.

If you are still deciding between a remodel and an addition, pair this guide with our home addition cost guide NJ and our home addition cost NJ 2026 guide. If you are weighing a full whole-home renovation instead, see our whole home renovation NJ guide and our whole home renovation service page.

Quick Summary: The Homeowner's Home Addition Hiring Checklist#

Why a Home Addition Is Fundamentally Different From a Remodel#

A kitchen remodel works inside existing walls. A bathroom remodel works inside existing plumbing walls. Even a whole-home renovation, if it stops short of a footprint change, still lives within your home's existing envelope. A home addition is new construction tied into existing construction. That shift — from "work on the house" to "build new structure and graft it onto the house" — changes everything about what kind of contractor you need.

New foundation or structural tie-in#

Every addition starts with either a new foundation (slab, crawlspace, or full basement) or a structural tie-in to the existing foundation. This requires:

• Site survey and soil analysis to determine bearing capacity
• Excavation and footings poured below the NJ frost line (42 inches in Mercer County)
• Foundation waterproofing and drainage tied into the existing system
• Structural engineer stamped plans showing how load paths transfer from new framing to new footings

A contractor who primarily does kitchens and baths often hires out the foundation work to a sub and never sees it again. That is the single biggest red flag in NJ home additions — if your contractor cannot answer detailed foundation questions from experience, find a different contractor.

New framing that ties into existing framing#

The connection point between the existing house and the new addition is where most addition failures happen 5-15 years later. Water intrusion, differential settling, drywall cracks, and sagging floors all trace back to how the addition was tied in. Per the 2021 International Residential Code (IRC) Section R301 — the structural provisions adopted by NJ's Uniform Construction Code — new framing that ties into an existing structure must maintain continuous load paths from roof to foundation and be detailed on engineered plans.

New roof tie-in and flashing#

The roof-to-wall transition between the existing roof and the new addition is the most-failed detail in NJ additions. Proper step flashing + counter-flashing + ice-and-water membrane (code-required in NJ per IRC R905.1.2 for the first 24 inches past the interior wall line in climate zones 5-7, which covers all of NJ) is non-negotiable. Shortcut this detail and you will have a leak within 3-7 years.

New mechanicals that tie into existing systems#

An addition means: - New electrical circuits tied into your existing panel (often requires panel upgrade — see NJ Uniform Construction Code electrical amendments) - New HVAC capacity (existing furnace/AC almost always undersized for the added square footage) - New plumbing runs if the addition includes a bath or kitchen - New insulation and air sealing per current NJ energy code (NJ adopted the 2021 IECC for residential)

These are not adjacent to the addition work — they are part of the addition work. A contractor who treats them as afterthought subcontracts usually leaves you with a mismatched system that runs inefficiently for the next 20 years.

New permits in multiple categories#

A full addition in NJ typically requires: - Zoning approval (setbacks, lot coverage, height — handled by the Zoning Officer) - Building permit (structural/framing/foundation — NJ UCC) - Electrical permit (separate subcode, separate inspector) - Plumbing permit (if plumbing work) - HVAC/mechanical permit (separate subcode) - Fire subcode (for any size change or egress change) - Certificate of Occupancy (final sign-off before you can use the space)

See our full NJ renovation permits guide and our Lawrence Township building permits guide for town-by-town detail. In the meantime, know this: a contractor who is new to additions often does not know they need to pull permits in all six categories above. When the Certificate of Occupancy is refused 5 months into the project, it is you who cannot move back into the space.

Step 1: Verify NJ HIC Registration (Before Any Other Conversation)#

New Jersey is one of the strictest states in the country for home improvement contractor oversight. Per the New Jersey Contractors' Registration Act (N.J.S.A. 56:8-136 through 56:8-152), any contractor who performs home improvement work valued at $500 or more must be registered with the NJ Division of Consumer Affairs. Unregistered contractors are violating state law, their contracts are void and unenforceable, and you — the homeowner — have no legal recourse if the project fails.

How to verify NJ HIC registration in 60 seconds#

1. 1Go to the official NJ Division of Consumer Affairs contractor verification tool
2. 2Enter the contractor's business name or registration number (every legitimate NJ contractor has one — it appears on their business cards, website, proposals, and contracts with the prefix "NJ HIC #")
3. 3Confirm: (a) the registration is active, (b) it is not expired or suspended, (c) the registered address matches what the contractor told you, (d) there are no open consumer complaints or administrative actions

If the contractor cannot produce an active HIC number, stop the conversation. There is no gray area — this is black-letter NJ consumer protection law.

What NJ HIC registration does NOT do#

Important distinction that trips up homeowners: NJ HIC registration does not mean the contractor is licensed or qualified to do structural, electrical, plumbing, or HVAC work. HIC is a consumer-protection registration, not a competency license. Per N.J.S.A. 45:1A-1 et seq., the actual trade licenses you need to verify are:

• Licensed Master Electrician — for any electrical work (wiring, panels, outlets, lighting)
• Licensed Master Plumber — for any plumbing work (supply, waste, fixtures, gas lines)
• Licensed HVAC contractor — for heating and cooling
• NJ Uniform Construction Code subcode officials — these are municipal inspectors, not your contractor

Your general contractor runs the project, but the electrical, plumbing, and HVAC work on the addition must be performed by separately-licensed tradespeople. A registered HIC contractor without licensed sub-trades is still breaking NJ law. Always ask: "Who is the licensed master electrician on my project? Licensed master plumber? Who pulls the electrical/plumbing permit?"

Step 2: Insurance and Bonding (Don't Skip This)#

A home addition is a 3-6 month project with crews on your property daily, heavy equipment maneuvering around your house, and thousands of pounds of materials staged on-site. The insurance requirements for additions are significantly more important than for interior-only remodels.

Minimum insurance every NJ home addition contractor should carry#

The certificate of insurance (COI) test#

Before signing any contract, require the contractor to have their insurance company send you a Certificate of Insurance (COI) with your name and address listed as "Certificate Holder". This is not a sales pitch from the contractor — it is an official document from the insurance company that confirms active, paid, in-force coverage. If a contractor refuses to provide a COI or delays producing one, that is a red flag. Per the National Association of Insurance Commissioners (NAIC) 2025 construction-liability reporting, uninsured or underinsured contractor claims are one of the top sources of homeowner financial devastation on additions.

Why workers' comp is non-negotiable#

If a roofer falls off your addition's roof mid-build and your contractor doesn't carry workers' compensation insurance, you the homeowner can be sued directly for the injury under NJ common-law liability theories. Your homeowners' insurance almost certainly will not cover a construction-site injury to a worker. This is the single most expensive mistake homeowners make on NJ additions.

Step 3: Structural Engineering Capability#

Every home addition in NJ larger than a small bump-out requires stamped structural engineering plans submitted with the building permit. Per NJ Uniform Construction Code Building Subcode (based on 2021 IBC/IRC), additions involving changes to the load path (new framing tied to existing, new foundation, roof tie-ins) must be signed and sealed by a NJ-licensed Professional Engineer or Architect.

What to ask prospective contractors#

1. 1"Who is your structural engineer?" — They should name a specific NJ-licensed PE or firm, with a long-standing working relationship. If they say "we find one for each job," that is a warning sign — it usually means they have no relationship and will hire the cheapest/fastest available, not the best.
2. 2"Can I see a previous stamped plan set?" — Legitimate contractors have these on file for every completed addition. Ask to see one for an addition similar to yours.
3. 3"Who pays the engineer?" — Should be the contractor as part of the project price. If they want you to pay the engineer separately, be cautious — this is how some contractors avoid accountability for plan errors.
4. 4"If the inspector requires a revision, who handles it?" — Should be the contractor coordinating with the engineer at no extra cost to you (within reason).

What engineered plans look like#

A proper NJ engineered addition plan set typically includes: - Site plan with setbacks, lot coverage calculations, and zoning compliance - Foundation plan showing footings, piers, waterproofing, and drainage - Framing plans for floor, wall, and roof with lumber sizing and species specified - Structural details showing tie-ins between new and existing framing - Electrical plan with load calculations (required if panel upgrade is needed) - Cross-sections showing insulation, air barrier, and vapor retarder per 2021 IECC - PE or architect's seal, signature, and license number on every sheet

If a contractor shows you a plan set without engineering stamps, that is a plan set that will not survive NJ permit review.

Step 4: Is the Foundation/Framing Crew In-House or Fully Subbed?#

This is the single most predictive question about the quality of your finished addition. A general contractor is allowed to subcontract — it is normal and expected for specialty trades (electrical, plumbing, HVAC). But if the foundation and framing crews are fully subbed out (not employed by the contractor, not supervised daily by the contractor), you are paying a general contractor to coordinate strangers.

Why this matters#

Foundations and framing are the invisible parts of your addition — once drywall goes up, you cannot see them again without a demolition. If those systems were rushed or done incorrectly, the failure modes (settling cracks, water intrusion, sagging floors, load-path failures) show up years later when the warranty is expired and the foundation sub is long gone.

What to ask#

• "Is your foundation crew on your payroll, or are they a sub?"
• "Is your framing crew on your payroll, or are they a sub?"
• "If there is a defect in the foundation 3 years from now, do you stand behind the repair, or do you refer me to the sub?"

At The 5th Wall, foundation and framing on every addition are built by the same father-son crew that bid the job. The person who measured your lot is the person who pours the footings and sets the sill plate. That continuity is why our addition warranties actually hold up — we are warranting our own work, not someone else's.

When a subbed framing crew is acceptable#

Larger contractors (3+ active addition crews simultaneously) sometimes run an in-house supervisor with a rotating framing subcontractor. If the same supervisor is on your site daily, the sub relationship is multi-year and documented, and the contractor stands behind the framing warranty 10+ years, that arrangement can be fine. The question is: is the accountability clear? If it is not, walk away.

Step 5: Permit Experience in YOUR Specific Municipality#

Mercer County has 10 towns we work across regularly, and permit processes vary meaningfully between them. A contractor who knows Hamilton Township inside and out may be a total novice at the Princeton permit office. A contractor who has done 40 additions in Lawrence but never one in West Windsor will struggle with West Windsor's more demanding inspection cycles.

Mercer County permit expectations for home additions (2026)#

Permits for full home additions in Mercer County cost significantly more than for interior remodels because multiple subcodes are triggered. Expect the total permit cost to be 3-6% of the project cost for most additions.

The "historic overlay" question in Princeton and Hopewell#

Princeton has historic districts (Princeton Historic District, Mercer Road Historic District, and others) where additions to contributing properties require review by the Princeton Historic Preservation Commission in addition to standard building permits. Hopewell Township has similar overlays in parts of Hopewell Borough and Pennington Borough. If your property falls in one of these districts, addition approval can add 2-4 additional months to the project timeline. A contractor who has not navigated this before will blow through deadlines and delays.

Ask directly: "Have you pulled a permit in [my municipality] for an addition in the last 18 months? Can I see that permit number?" Real contractors keep permit records and can produce them.

For a deeper look at Princeton historic considerations, see our Princeton NJ home renovation historic guide.

Step 6: Real NJ Home Addition Cost Ranges (2026)#

Before you interview contractors, know what a legitimate addition costs in Mercer County in 2026. Contractors whose bids come in 30-50% below the ranges below are not cheaper — they are leaving something out that will surface as a change order or a corner-cut later.

Cost by addition type (Mercer County, 2026)#

Cost per square foot varies widely because fixed costs (engineering, permits, foundation, utility tie-ins, roof tie-ins) spread across smaller additions at a higher per-square-foot rate. A 100-sq-ft bump-out has nearly the same foundation and engineering cost as a 250-sq-ft room addition — the smaller project has fewer square feet to absorb it.

Where the real variables live#

Per 2024 HomeAdvisor and Angi cost data, NJ addition costs run roughly 15-25% above the national average because of labor rates, stricter code enforcement, and permit complexity. Within NJ, Mercer County pricing reflects:

• Older-home tie-ins add 15-20% contingency (1940s-70s housing stock common in Lawrence, Hamilton, Ewing, Trenton)
• Structural complexity — cantilevers, bump-outs over garages, second-story additions without matching first-floor wall alignment
• Site access — narrow lots in Princeton and Pennington require material stage-in that adds labor
• Foundation type — full basement adds $20-40/sq ft over slab; matching a crawl-space existing house adds complexity
• Finish level — builder-grade vs. mid-range vs. premium finish tripling the finish cost
• Mechanicals upgrade — existing panel/HVAC often needs replacement, not just extension

For a deeper price breakdown, see our home addition cost NJ 2026 guide and our home addition cost Princeton NJ guide.

Step 7: 10 Red Flags When Interviewing NJ Addition Contractors#

These are the warning signs we have seen ruin NJ additions over two decades of watching the industry. If you see any one of these, be cautious. If you see more than one, walk away.

1. No NJ HIC registration number on the first page of the proposal#

Legitimate NJ contractors put their HIC number on every proposal, business card, and contract page by reflex. A contractor who has to dig for it or doesn't include it is either new, unregistered, or hiding something.

2. The proposal is a single-page lump sum#

A $180,000 home addition that comes back as "$180,000, estimated 4 months" with no line items is a proposal designed to hide scope gaps. Real proposals break cost into: demo, foundation, framing, roofing, windows/doors, electrical, plumbing, HVAC, insulation, drywall, flooring, trim, paint, permits, engineering, contingency, and profit/overhead.

3. Heavy front-loaded payment schedule#

Per N.J.A.C. 13:45A-16.2 (NJ home improvement contract regulations), the payment schedule must be reasonable and tied to work progress. A contractor asking for 50%+ upfront is violating the spirit of NJ consumer protection law and often is using your money to finish the previous customer's job. Standard NJ payment schedules look like:

• 10-15% at contract signing (deposit)
• 15-25% at permit pulled / excavation start
• 20-25% at foundation complete + framing start
• 20-25% at rough mechanicals complete
• 15-20% at drywall complete
• 5-10% at final (after inspection, walk-through, and punch-list complete)

4. Pressure tactics: "This price is only good for 48 hours"#

Legitimate contractors do not pressure you. Your addition will cost what it costs. If a contractor uses limited-time pricing or "decide today" language, they are running a scripted sales pitch, not a contracting business.

5. Cash-only or off-the-books discounts#

"I'll take 15% off if you pay cash" = the contractor is not running this job through their books = no receipt for you = no warranty = no liability coverage = no recourse. This is illegal tax evasion on the contractor's side and financial suicide on yours. Walk away.

6. Cannot name their structural engineer#

If the contractor cannot name a specific NJ-licensed PE or architect they work with regularly, they are not building additions — they are bidding them and hoping to figure it out later. See Step 3 above.

7. No past-client references for addition-specific work#

Kitchen and bath references do not count. Ask for 3 home addition references from projects completed in the last 2 years, and call them. Ask the former clients: did the project finish on time? On budget? Did the contractor stand behind punch-list items after completion? Would they hire them again for another addition?

8. Vague about permits#

"Don't worry about permits, I handle all that" without specifics is a red flag. A real contractor says: "For your Hamilton Township project, we'll pull building, electrical, plumbing, HVAC, and fire subcode permits. Site plan review isn't required because you're under the 250 sq ft threshold. Estimated permit cost is $3,200 and processing is 3 weeks after plans are submitted. We factor that into the timeline."

9. No proof of workers' compensation insurance#

Asking "can I see your COI with workers' comp listed?" should produce a certificate within an hour. A contractor who resists or delays is uninsured. See Step 2 above for the financial exposure to you.

10. The bid is 30%+ below the other bids#

If three contractors bid $190K, $205K, and $220K and a fourth bids $135K, the fourth is not cheaper — they are either (a) leaving out material scope that will become change orders later, (b) planning to substitute cheaper materials without telling you, (c) bidding intentionally low to win, then walking away when they realize they cannot complete at that price, or (d) new to additions and legitimately do not know what it costs. None of these outcomes end well for you. The contractor in the middle of the pack, with verified credentials and strong references, is almost always the right choice.

The Father-Son Approach: Why a Small Crew Is an Advantage on Additions#

Home additions are long, high-stakes projects. The contractor who bids the work, prices the work, and builds the work being the same person — not a sales rep who hands you off to a project manager who hands you off to a foreman — is the single biggest predictor of a smooth project.

At The 5th Wall, when you hire us, you get Stefanos and Tony. We measure your lot. We price the job. We pull the permits. We pour the footings. We frame the walls. We tie in the roof. We punch out the final walkthrough. There is no layer between the person quoting and the person building.

Why that matters specifically on additions#

• Accountability is clear. Defects 5 years later trace back to the two people who actually did the work — no finger-pointing at a sub who's moved on.
• Decisions are faster. When an unexpected condition comes up mid-build (old framing, unexpected water line, ledger-board surprise), we decide on-site without a chain of phone calls back to a project manager.
• Quality stays consistent. Every joint, every flashing detail, every tie-in is executed by people who will be in your backyard tomorrow building the next phase — not a rotating crew rushing to finish and move on.
• Communication is direct. You have our phone numbers. You text us. We text back. No project-manager intermediary filtering what gets communicated.

What a small crew can't do as fast#

To be honest about the tradeoff: a father-son crew completes one addition at a time. If you need to start in 30 days and you're our next job, we can do that. If you need to start today and we're mid-project, you'll wait for us — or you'll hire someone else. A 15-person general contracting firm can run 3-4 addition projects simultaneously and start sooner. What they can't do is put the same person who measured your lot into the footing pour six weeks later.

For more on how our team works, see our father-son contractor NJ guide and our licensed contractor NJ guide.

Mercer County-Specific: Matching Addition Type to Housing Stock#

The magazine version of a home addition assumes you own a center-hall colonial on an acre with no setbacks and generous lot coverage allowance. Most of our Mercer County clients do not. Here is how additions actually play out across the county.

Princeton colonials and Tudor-style homes (1920s-1960s)#

Princeton housing stock presents three constraints on additions: 1. Historic district review — additions to contributing properties require Historic Preservation Commission approval, which can add 2-4 months and specific material/style constraints 2. Lot setback constraints — many Princeton lots have setback requirements that limit where an addition can go 3. Architectural integrity — matching slate roofing, brick courses, window proportions, and trim details that Princeton HPC reviews

Typical addition types that work: - Rear addition that respects the primary ridge line (often requires engineered valley) - Carriage-house-style detached garage with upper living space (ADU potential) - Sympathetic bump-out preserving the original facade

Hamilton and Ewing splits and ranches (1950s-1970s)#

Tight lots, often under-engineered original framing, and galvanized/cast-iron plumbing present different challenges: 1. Original framing was often under-spec'd — supporting a new second-story addition often requires sistering existing joists and beams 2. Electrical service is often still 100A with aluminum branch wiring — addition always requires panel upgrade to 200A minimum 3. Crawl-space foundations common — tying an addition into a crawlspace requires different foundation strategy than full basement

Typical addition types that work: - Ground-floor family room or primary bedroom addition (no structural existing-framing load) - Detached garage with bonus space above (decouples addition from existing-house constraints)

Lawrence and Lawrenceville colonials (1970s-1990s)#

The sweet spot for NJ additions — decent lot size, engineered framing, sensible setbacks, and a permit office that processes standard additions in 2-4 weeks. Most addition types are feasible.

Typical addition types that work: - Full two-story rear addition (respects existing roof line, adds primary suite + bedroom or office) - Master suite over existing garage (cost-effective; foundation already exists) - Family-room bump-out with expanded kitchen/eat-in reconfiguration (pair with kitchen remodel)

West Windsor, Robbinsville, and Hopewell new builds (2000s+)#

Newer housing stock presents different constraints: 1. HOA architectural review committees — almost every new-build community has ARC that must approve addition design before permits can be pulled 2. Tight setbacks and impervious-coverage limits — many newer lots have already used most of their lot coverage allowance 3. Standardized framing — additions tie in easily because original framing is documented

Typical addition types that work: - Sunroom or four-season addition (ARC-friendly, doesn't change roof line) - Primary suite bump-out (if setback permits) - Basement finishing + addition combo (maximizes existing footprint before adding new)

For a broader view of Mercer County housing styles, see our Mercer County home styles renovation guide.

NJ Permit Timeline Expectations for Additions (2026)#

This is the timeline most homeowners underestimate. Between signing a contract and pouring concrete, most Mercer County additions wait 2-4 months for permits and engineering. Here is how the timeline actually sequences.

For most Mercer County 2026 addition projects, we tell clients: if you want to break ground April 1, sign a contract no later than January 1. Historic district projects in Princeton or Hopewell add another 6-12 weeks. HOA-reviewed projects in West Windsor/Robbinsville add 4-8 weeks.

See our renovation timeline NJ guide for a broader look at project timelines.

Financing an NJ Home Addition in 2026#

Most Mercer County additions ($75K - $500K range) are financed through one of four paths. Each has tradeoffs.

1. Home Equity Line of Credit (HELOC)#

Most common. Tap equity in your home, draw only what you need, interest-only during construction. Typical 2026 NJ HELOC rates: 7.5% - 9.5% variable. Best if you have strong equity and a high credit score.

2. Renovation Loan (FHA 203(k) or Fannie Mae HomeStyle)#

Purpose-built for renovations and additions. Single loan wraps mortgage + renovation cost. Typical 2026 rates: 6.5% - 8.0% fixed. Best if you're buying a house you plan to add onto, or refinancing a mortgage with meaningful renovation included.

3. Cash-Out Refinance#

Replace existing mortgage with a new, larger one; take the difference as cash. Typical 2026 rates: 6.5% - 7.5% fixed. Best if current mortgage rate is higher than today's, and you want to consolidate.

4. Personal Loan#

Unsecured. Fast. Limited amounts (typically under $100K). Typical 2026 rates: 9% - 15%. Best only for smaller additions under $75K, typically bump-outs.

Pre-qualify with lenders before you sign the construction contract — nothing stalls a project faster than a financing delay after permits are pulled and materials are ordered.

The Contract: What to Look for Before Signing#

Per N.J.A.C. 13:45A-16.2, NJ home improvement contracts must include specific provisions. Do not sign any contract that is missing these.

NJ-mandated contract provisions#

1. 1Contractor's full legal name, business address, and HIC registration number
2. 2Homeowner's name and address
3. 3Detailed description of work to be performed (not "addition work" — specific scope)
4. 4Start date and substantial completion date
5. 5Total contract price (not "approximate")
6. 6Payment schedule tied to progress (see Step 7 above)
7. 7Homeowner's three-day right of cancellation (N.J.A.C. 13:45A-16.2(a)(12))
8. 8Contractor's commercial general liability insurance information
9. 9Signatures of both parties

Additional provisions we include in every Fifth Wall contract#

• Change order procedure — signed by both parties before additional work, with pricing
• Dispute resolution process — informal conversation first, then mediation, then arbitration
• Warranty terms — we provide 5-year workmanship on all addition structure, 1-year on finish work
• Punch-list protocol — how we handle final walk-through items
• Payment retention — 10% withheld until punch list is 100% complete
• Cleanup and site condition — daily broom-clean, weekly disposal

If a contractor's contract is missing any NJ-mandated provision, do not sign. This is a legal requirement, not a negotiation.

Ready to Start Your NJ Home Addition?#

At The 5th Wall LLC, we are a father-son contractor team based in Lawrence NJ — Stefanos and Tony Karpontinis. We are NJ HIC-registered (HIC #13VH13203500), carry $2 million in liability insurance plus full workers' compensation, and we build additions across all 10 Mercer County towns: Lawrence, Princeton, Hamilton, Ewing, Trenton, Lawrenceville, Pennington, Robbinsville, West Windsor, and Hopewell.

When you call us, you get us. Not a project manager. Not a foreman. Not a sales rep. The person who measures your lot is the same person who pours the footing, sets the framing, ties in the roof, and walks the final punch list with you.

What we do before quoting your addition#

1. 1In-person site survey — we walk the property, look at the existing foundation and attic, assess lot setbacks and grade
2. 2Engineered-plan coordination — we introduce you to our PE partner and walk through structural feasibility
3. 3Detailed itemized proposal — line items for every scope category, not a lump sum
4. 4Permit and timeline transparency — we tell you exactly which permits, how long, and what could delay them
5. 5Reference check — we give you names and numbers of 3 recent addition clients, not stock photos

Our Mercer County addition portfolio includes#

• Master-suite additions in Princeton and West Windsor
• Two-story rear additions in Lawrence and Lawrenceville
• Family-room + kitchen-expansion bump-outs in Hamilton and Ewing
• In-law suite additions in Pennington and Hopewell
• Garage with bonus-room additions in Robbinsville

Call us at (762) 220-4637 to schedule a free in-home consultation. We'll walk the property, talk through what you want the addition to do for your family, and give you a realistic timeline and budget range before you sign anything.

If you're still figuring out whether an addition is the right move versus a remodel, our kitchen vs bathroom remodel NJ guide and our home renovation ROI NJ guide are good next reads. For the service overview, see our whole home renovation service page.