Home Addition Cost in DFW

What a DFW home addition actually costs in 2026

Home addition cost in DFW ranges from about $48,000 for a single sunroom in Rowlett or Sachse, up to $2.5 million for a full second-story estate expansion in Highland Park. Additions are different from renovations: you’re creating new square footage, which triggers permits, engineering, foundation work, and typically a full architectural review.

2026 DFW addition costs are up 7–11% year-over-year, driven by two things: structural engineering demand (every Collin County addition now requires stamped plans, and engineers are booked 6–10 weeks out), and foundation construction costs (new pier-and-beam or slab foundations rose with steel and concrete prices). If you were quoted $180,000 for a wing addition in 2024, expect $205,000–$215,000 in 2026 for the same scope.

UHS Remodeling handles additions from concept to certificate of occupancy under one fixed-price contract. We manage the structural engineer, the surveyor, the permit submittals, the HOA review, the foundation crew, framing, MEP, insulation, drywall, and finishes. You sign one contract; you get one point of contact.

The 3 addition types (and what each one actually costs)

Type 1 — Single-Room / Bump-Out Addition ($48K–$180K)

A single-room addition expands the existing footprint by one room. Typical scope: 150–400 sq ft of new space, new slab foundation or pier-and-beam, new framing tied into existing roof, electrical extension, HVAC zone extension, windows, drywall, flooring, paint. Common uses: sunroom, home office, extended master bedroom, or a larger kitchen bump-out. Timeline: 10–18 weeks. Best for homeowners who need just a bit more room without reworking the whole house.

Type 2 — Wing / Multi-Room Addition ($160K–$650K)

A wing addition adds 500–1,200 sq ft and typically 3–6 new rooms. Scope: full slab foundation, new framing, new roof integration, dedicated HVAC zone, new electrical panel subfeed, new plumbing rough-in, windows, doors, and full finishes. Common uses: new primary suite with walk-in closet and bath, guest wing with private entry, or family-room + playroom + kids’ bath combo. Timeline: 20–28 weeks. This is the dominant addition type in Frisco, Allen, Richardson, Plano, and McKinney as families expand.

Type 3 — Second-Story Addition ($340K–$2.5M+)

Adding a second story is the most complex DFW addition type. Scope: structural analysis and reinforcement of existing foundation, new stair construction (often requires relocating utilities), complete framing of second floor, roof tear-off and rebuild, new HVAC system (almost always), full MEP extension upstairs, windows, finishes. Typical size: 1,200–2,800 new sq ft. Timeline: 30–48 weeks. Most common in Highland Park, University Park, older Plano, and M Streets Dallas where lots are small and single-story homes need more space.

Home addition cost by DFW city (2026)

Here’s what a full addition (Type 2 — wing/multi-room) actually runs in 2026 across the 19 DFW cities UHS Remodeling serves. Each city link goes to our dedicated home addition page for that city with tier breakdowns, typical scope, and local permit notes.

What an addition actually costs per square foot in DFW (2026)

The per-square-foot number is the question every DFW homeowner asks first, and the honest answer is “it depends on foundation, finish level, and city.” Here is the real 2026 range UHS Remodeling sees on signed contracts:

• Single-room bump-out, standard finish: $220–$340/sq ft. Example: a 350 sq ft sunroom in Allen runs $77,000–$119,000.
• Wing addition, mid-range finish: $280–$420/sq ft. Example: an 850 sq ft primary suite wing in Plano runs $238,000–$357,000.
• Wing addition, high-end finish: $400–$580/sq ft. Example: a 900 sq ft in-law suite in Frisco with custom cabinets, high-end fixtures, and stone counters runs $360,000–$522,000.
• Second-story addition, standard: $280–$475/sq ft. Example: a 1,400 sq ft second floor in older Plano runs $392,000–$665,000.
• Second-story addition, estate: $450–$650/sq ft. Example: a 2,200 sq ft second floor in Highland Park runs $990,000–$1.43M.
• Detached guest house / ADU: $320–$520/sq ft. Example: a 700 sq ft casita in Prosper runs $224,000–$364,000.

Why the wide spread? Three factors: (1) foundation condition — slab-on-grade homes in DFW clay soil often need soil stabilization before any new foundation can be poured; (2) MEP routing — running new plumbing, electrical, and HVAC across an existing home adds labor costs disproportionately; (3) finish level — the same 800 sq ft footprint can be finished with $18,000 of flooring and fixtures or with $95,000 of flooring and fixtures.

2026 DFW addition cost breakdown: where the money actually goes

For a typical 800 sq ft wing addition in Frisco or Plano priced at $295,000, here is where every dollar actually goes. These numbers come from UHS Remodeling’s internal costing spreadsheet for signed 2025–2026 contracts.

Design, engineering, and permits ($18K–$28K, 6–10% of total)

Architectural drawings: $6,500–$12,000 depending on scope. Structural engineering (stamped plans required by every DFW city): $3,500–$8,500. Survey and site plan: $650–$1,400. Soil report (required for new slab construction in some cities): $1,200–$2,200. City permit: $1,800–$4,500 depending on project valuation and city.

Foundation ($35K–$65K, 12–22% of total)

For an 800 sq ft slab-on-grade addition: excavation $4,500–$8,000, forms and rebar $8,000–$14,000, concrete pour $14,000–$22,000, post-tension cables (common in DFW clay) $3,500–$6,500, soil prep and compaction $5,000–$14,000. Pier-and-beam additions run $8,000–$15,000 higher due to pier installation and beam layout.

Framing and structure ($45K–$85K, 16–28% of total)

Wall framing, roof framing, sheathing, house-wrap, and tie-in to the existing structure. Includes the structural beam at the break-through where the new addition meets the existing home — typically the most expensive single line item on an addition, because it often requires temporary shoring and a steel beam to replace a load-bearing wall.

Roofing and exterior ($18K–$38K, 6–13% of total)

New shingles or tile to match the existing home, new fascia, new soffit, new gutters, and an exterior paint or stucco pass on the new wing and the seam where it meets the original home. For brick homes, expect to pay $8–$16/sq ft of brick face to match the existing brick color and course pattern.

MEP rough-in ($28K–$55K, 10–19% of total)

Plumbing rough-in for new baths and laundry: $12,000–$22,000. Electrical rough-in with a new sub-panel: $8,500–$18,000. HVAC rough-in with a new zone or dedicated mini-split: $7,500–$15,000. These three trades work in sequence and each gets an inspection before insulation.

Insulation, drywall, and finishes ($85K–$145K, 30–50% of total)

Insulation (spray foam or batts): $5,500–$9,500. Drywall, taping, texturing or smooth finish: $12,000–$22,000. Trim (baseboards, casing, crown, door casing): $6,500–$14,000. Paint: $5,000–$9,500. Flooring: $15,000–$38,000. Cabinetry and counters (if bath or kitchen is included): $18,000–$45,000. Tile (bath and backsplash): $8,500–$22,000. Doors and hardware: $3,500–$7,500. Finish plumbing fixtures: $4,500–$14,000. Finish electrical devices and light fixtures: $5,500–$12,000.

Week-by-week timeline of a 24-week DFW wing addition

Weeks 1–3 — Design and engineering

Architectural drawings finalized, structural engineering completed, selections locked. Purchase orders go out to cabinet, window, and long-lead material suppliers.

Weeks 3–7 — Permits and HOA review

Permit submittal and HOA architectural review happen in parallel. Frisco, Plano, and Allen average 2–3 weeks; Highland Park and University Park average 4–6 weeks; HOAs add 3–6 weeks on top. During this time the crew continues prior projects.

Weeks 7–8 — Site prep and excavation

Site clearing, tree protection, utility locates, temporary fencing, and excavation for the new foundation footprint. Soil compaction and plumbing ground-rough happen in parallel.

Weeks 8–9 — Foundation pour

Forms, rebar, post-tension cables, and pour. Concrete cures for 7–10 days before framing can begin.

Weeks 10–13 — Framing and roof

Wall framing, floor system (for second-story additions), roof framing, sheathing, roof-dry-in, house-wrap, windows and exterior doors installed. The addition is “dried in” — weatherproof enough to work inside.

Weeks 13–15 — Rough MEP

Plumbing, electrical, and HVAC rough-in. First round of inspections at the end of week 15.

Weeks 15–17 — Insulation and drywall

Insulation inspection, drywall hanging, taping, texture or smooth finish. Prime coat.

Weeks 17–21 — Finishes

Flooring, cabinetry, tile, trim, interior doors, paint.

Weeks 21–23 — Finish MEP, counters, fixtures

Countertop install, finish plumbing, finish electrical, appliances, hardware.

Weeks 23–24 — Punch list, final inspections, certificate of occupancy

Touch-up, cleaning, final inspections, walkthrough, keys, warranty package, and filing for the Certificate of Occupancy with the city.

5 most common DFW addition types

Primary Suite Addition ($120K–$420K)

The #1 addition request in Plano, Frisco, Allen, and McKinney. Typical scope: 500–900 sq ft new suite with bedroom, large walk-in closet, primary bath with double vanity and walk-in shower, often a small coffee bar. Adds 400–700 sq ft to appraised value. Timeline: 18–24 weeks.

Second-Story Master Addition ($520K–$1.2M)

Common in University Park, Highland Park, and M Streets Dallas. Relocates the primary suite upstairs to free ground-floor space for expanded living and kitchen. Scope: partial second story with primary suite, primary bath, closet, sometimes a sitting room. Requires foundation reinforcement. Timeline: 26–36 weeks.

Guest House / Casita ($180K–$520K)

Popular in Prosper, Frisco, and Dallas. A detached accessory structure typically 450–900 sq ft with bedroom, full bath, kitchenette, and living area. Permitted as an Accessory Dwelling Unit. Timeline: 22–32 weeks. HOA approval is almost always required.

Sunroom / Four-Season Room ($65K–$180K)

A glazed addition integrated with the existing home. Modern four-season rooms include insulated walls, climate control, and full HVAC. Timeline: 10–16 weeks. Best return-on-investment of any addition type in most DFW markets.

Garage Conversion + Addition ($85K–$260K)

Convert existing garage to living space AND build a new detached garage elsewhere on the lot. Common in Plano, Richardson, and Dallas. Creates 400–600 sq ft of new living plus a refreshed garage. Timeline: 18–26 weeks. Good ROI because the conversion is cheaper than new construction.

City-specific permit and HOA notes for additions (top 8 DFW cities)

Plano

Addition permits average 15–22 business days. Plano requires stamped structural engineering for every addition, plus a survey showing the new footprint, setbacks, and any protected trees. Fees run roughly $2–$3 per sq ft of new construction — an 800 sq ft addition costs $1,600–$2,400 in permit fees. Plano enforces front setback, rear setback, and side setback strictly, and will deny permits for additions that violate lot coverage.

Frisco

Addition permits average 18–25 business days. Frisco requires a soil report for any new foundation over 500 sq ft, plus stamped structural. Fees are valuation-based and run $2,200–$5,500 for most additions. Stonebriar, Starwood, Phillips Creek Ranch, and Hollyhock HOAs all have strict architectural review with 4–6 week review cycles and require full material boards.

Allen

Addition permits average 12–18 business days. Allen is more lenient on lot coverage than Plano or Frisco but strict on exterior finish — new brick must match existing, new siding must match existing, new roofing must match existing.

Richardson

Addition permits average 14–20 business days. Richardson has older lots with smaller setbacks, which means additions often trigger a variance request. Variance hearings happen monthly and add 4–8 weeks to the schedule.

McKinney

Addition permits average 15–22 business days. McKinney historic district requires Certificate of Appropriateness for exterior changes, reviewed by the Historic Preservation Commission. Modern subdivision additions move through standard building permit with faster turnaround.

Dallas (City of)

Addition permits average 25–40 business days — the slowest in DFW and often the biggest schedule risk for Dallas additions. The Sustainable Development Department may require additional drawings, energy calculations, or stormwater management plans. Plan for 6–8 weeks from submittal to approved permit.

Highland Park

Addition permits average 20–35 business days plus the Design Review Board process, which meets twice monthly. Full Highland Park addition approval timeline: 10–16 weeks from submittal. Fees are flat and run $4,500–$12,000 depending on project scope. Highland Park strictly enforces height, lot coverage, and setback ordinances — expect minor redesigns during review.

University Park

Addition permits average 18–28 business days. University Park’s ordinance on building height is stricter than most DFW cities — many second-story additions require a variance or design compromise. HOA-style architectural review adds another 3–4 weeks on top.

Permits, HOA, and the DFW addition approval process

• Survey and site plan. Every addition starts with a property survey ($650–$1,400) and a site plan showing setbacks, easements, and the new footprint.
• Stamped structural plans. Every DFW city requires stamped plans from a licensed structural engineer for any addition. Cost: $3,500–$15,000 depending on complexity.
• City permit. Plano charges roughly $1.50–$2.50 per sq ft of new construction. Highland Park charges flat fees starting around $3,500. Frisco and McKinney use sliding-scale fees tied to project valuation.
• HOA architectural review. Highland Park, University Park, Stonebriar (Frisco), Starwood (Frisco), Prosper Village, and several others require a full HOA packet with elevations, materials list, and neighbor notifications. Review: 3–8 weeks.
• Inspections. Every addition has 6–12 inspections from foundation through final CO. Budget 3–6 weeks of inspection time across the project timeline.

Foundation: the biggest cost variable in additions

Foundation work is often 15–25% of the total addition cost and almost always the biggest source of surprise. DFW clay soil makes foundations expensive regardless of addition size. A good rule of thumb for 2026:

• Slab-on-grade addition (400 sq ft): $18,000–$35,000 for engineering + excavation + forms + rebar + pour.
• Pier-and-beam addition: $22,000–$45,000 depending on number of piers and access.
• Foundation reinforcement for second story: $25,000–$85,000 depending on whether new piers are needed under existing footings.
• Matching existing foundation elevation: Almost always adds $5,000–$12,000 for leveling and tie-in.

10 hidden costs that blow up DFW addition budgets

• Tree protection fencing. Plano, Highland Park, and University Park require physical fencing around protected trees during construction. Budget $1,500–$4,000.
• Stormwater management. Dallas and some Frisco subdivisions require a stormwater plan for new impervious surface over 500 sq ft. Engineering: $2,500–$6,500. Physical detention features if required: $8,000–$25,000.
• Electrical service upgrade. Most older DFW homes have 100A or 150A service. A new wing with a primary suite, HVAC zone, and modern kitchen triggers a 200A or 320A upgrade. Cost: $3,500–$8,500.
• Gas line extension. New kitchens, fireplaces, or tankless water heaters need gas. Extending the gas line from the existing meter to the new addition: $1,800–$5,500.
• Sewer tap and water line extension. If the new wing includes plumbing, the existing main line may not have capacity. New tap: $2,500–$8,000. Water line upsizing: $3,500–$12,000.
• HVAC resize. Adding 800+ sq ft to a house almost always exceeds the existing HVAC capacity. Plan for a new dedicated zone ($4,500–$9,500) or a full HVAC replacement ($12,500–$22,500).
• Drainage and grading. New construction changes site drainage. Regrading and French drains: $3,500–$12,000.
• Impact fees. Some DFW cities charge impact fees for new living space that ties into city water and sewer. Plano: $0. Frisco: $850–$2,200. Prosper: $1,500–$3,800. Highland Park: none for additions.
• Temporary power. During construction, the addition needs a temporary pole with a meter before the permanent electrical is energized. Oncor/Centerpoint set-up: $500–$1,200.
• Certificate of Occupancy inspection failures. If any inspection fails, re-inspection fees plus crew downtime add $1,500–$5,000 per failure. Budget one failure into every project.

Second-story additions: is your home a candidate?

Not every DFW home can take a second story. Before committing $500,000+ to an upstairs addition, verify these five things with a structural engineer.

• Foundation capacity. A slab-on-grade foundation designed for a single story may need new piers driven under existing footings. Cost of reinforcement: $40,000–$85,000 on top of the addition. For some homes it is uneconomical — demolish and rebuild is cheaper.
• Existing framing. The existing ceiling joists become the new floor joists upstairs. They must be inspected for size, spacing, and condition. Sistering or replacing joists adds $6,000–$18,000.
• Stair location. A second floor needs stairs, and in many older homes there is no obvious place to put them without sacrificing a bedroom or rework of the living area. Stair construction and trim: $18,000–$45,000.
• HVAC replacement. The existing HVAC was sized for one floor. A second floor almost always requires a full system replacement. Budget $15,000–$32,000.
• Roof tear-off and rebuild. The existing roof must come off. Weather risk during the tear-off is real — we stage the demo, framing, and dry-in as a single continuous operation to minimize exposure. Cost: $28,000–$75,000 depending on pitch and material.

6 questions every homeowner should ask a DFW addition contractor

• “Will you provide stamped structural engineering drawings before I sign?” Real addition contractors pre-engineer the project before asking for a deposit. Contractors who promise “we’ll figure it out during permit” are flagging that they have not actually designed the structure yet.
• “Who pulls the permit — you or me?” The correct answer is: the contractor pulls the permit under their license. Some shady operators ask the homeowner to pull an “owner-builder” permit, which transfers legal liability to the homeowner and usually means the contractor is not licensed or insured.
• “What happens if the city requires redesigns during permit review?” The correct answer is: “We handle the revisions and submit at our cost.” Red flag answer: “We charge hourly for revisions.”
• “Can I see a 3D model or detailed drawings of the finished addition?” Real contractors use 3D modeling (SketchUp, Chief Architect, or Revit) so the homeowner can see the final look before committing. Contractors working from 2D floor plans only are underinvested in design.
• “How do you handle the tie-in between the new addition and the existing home?” The correct answer covers: structural beam at the break-through, roof integration, siding/brick match, interior drywall tie-in, floor transition. If the answer is vague, the contractor has not thought through the most critical detail.
• “What’s your written warranty on the addition structure?” UHS Remodeling offers a 3-year written warranty on the full addition including structural, MEP, and finishes. Industry standard is 1 year. Anything less than 1 year is a red flag.

3 real UHS additions (scope, cost, outcome)

Case study 1: Allen primary suite wing ($238,000)

A 2004 two-story in Allen, 2,400 sq ft original footprint. The family wanted to convert the existing primary bedroom into a home office and add a new primary suite wing off the back of the home. Scope: 720 sq ft wing with primary bedroom, walk-in closet, and primary bath (double vanity, freestanding tub, walk-in shower, private water closet). New dedicated HVAC zone, new sub-panel, Pella 250 windows, LVP flooring, semi-custom cabinets, quartz counters. Timeline: 22 weeks including HOA review. Appraisal increase: $185,000 (78% ROI).

Case study 2: Frisco two-story in-law suite ($385,000)

A 2010 two-story in Stonebriar, 3,400 sq ft original. The family wanted a ground-floor in-law suite for aging parents with private entry. Scope: 950 sq ft wing with bedroom, full bath (walk-in shower with grab bars, comfort-height vanity), kitchenette, sitting room, and private exterior door. Full ADA-accessible design. New dedicated HVAC zone, new sub-panel, kitchenette plumbing, engineered hardwood. HOA architectural review took 5 weeks. Timeline: 26 weeks total. Appraisal increase: $225,000 (58% ROI) plus significant quality-of-life benefit for the family.

Case study 3: University Park second-story addition ($1.12M)

A 1952 one-story cottage in University Park, 1,850 sq ft original. The family wanted to preserve the original ground-floor charm while adding a second floor with primary suite and two kids’ bedrooms. Scope: 1,650 sq ft second-story addition with primary suite, primary bath, two kids’ bedrooms, shared kids’ bath, stair tower, new 4-ton HVAC system, full roof tear-off and rebuild, new fiberglass windows, foundation reinforcement with six new piers. Timeline: 42 weeks. Family moved out for 36 of those weeks. Appraisal increase: $845,000 (75% ROI).

10 FAQs DFW homeowners ask about additions