Plan HG-1531•Duplex / Multi-Gen•40' × 26' Footprint

1,040 Sq Ft (26x40) 3 Bed 2 Bath Duplex / Multi-Gen Floor Plan (STC-60 Mirrored Acoustic Party-Wall Duplex)

1,040 sq ft heated living • 3 Bedrooms, 2 Baths • Free 2D CAD Blueprint (.SVG)

Download Free CAD (.SVG)

Room Dimensions & Zones

40' × 26' Shell

UNIT A SUITE

138 sq ft

12'-0" × 11'-6"

UNIT A BATH

92 sq ft

8'-0" × 11'-6"

UNIT A LIVING

174 sq ft

12'-0" × 14'-6"

UNIT A KITCHEN

116 sq ft

8'-0" × 14'-6"

UNIT B BATH

92 sq ft

8'-0" × 11'-6"

UNIT B SUITE

138 sq ft

12'-0" × 11'-6"

UNIT B KITCHEN

116 sq ft

8'-0" × 14'-6"

UNIT B LIVING

174 sq ft

12'-0" × 14'-6"

Build Cost Estimator

Estimated Cost to Build (40' × 26' Duplex / Multi-Gen)

Region:

Shell / Building Kit

$42,000 – $54,000

Framing package, roof trusses & exterior shell for 1,040 sq ft base.

Owner-Builder

$108,500 – $142,500

Saves ~$48,500 by managing local slab & interior trades.

Turnkey Builder

$157,000 – $191,000

Full general contractor finish including slab, HVAC, kitchen & baths.

Est. Monthly Payment

$903 / mo

$139,200 financed (30-Yr)

Down Payment:20%

Interest Rate:6.75%

Free Vector CAD Blueprint • Plan HG-1531

Download 40' × 26' Duplex / Multi-Gen Floor Plan (.SVG)

Scalable 2D architectural vector drawing with exterior and room dimensions, door swings, and fixture layout. Opens in AutoCAD, Illustrator, Inkscape, or any browser.

Material Takeoff & Framing Specifications

Concrete volume (21 yd³), roof surface (~1,262 sq ft), wall framing & architectural notes

Building Package	Specification	Quantity	Est. Range
Structural Shell & Trusses	40'×26' 2x6 Exterior + Double-Stud Insulated Acoustic Party Wall	1,040 sq ft shell kit	$42,000 – $54,000
Concrete Slab & Grade Beams	Monolithic Concrete Slab w/ Dual Sewer/Water Stub-Outs	21 Cubic Yards (4,000 PSI)	$10,750 – $13,750
Roofing & Underlayment	Architectural Shingle or Standing Seam Metal Hip/Gable (5:12 Pitch)	16 Roofing Squares (1,600 sq ft)	$6,720 – $10,880
Closed-Cell Spray Foam / Insulation	3" Closed-Cell Wall & Roof Deck Thermal Envelope (R-21 to R-38)	7,350 Board Feet	$9,923 – $13,598
Windows & Exterior Doors	Low-E Argon Black Architectural Glazing + 36" Fiberglass Entry	4 Windows • 6 Doors	$3,800 – $6,020
HVAC & Multi-Zone Mini-Split	High-SEER2 Heat Pump / Ductless Mini-Split System	2 Ton (24,000 BTU/hr)	$5,200 – $8,200

Exterior Perimeter

132 Linear Ft

Interior Partitions

~132 Linear Ft

Est. Concrete Slab

21 Cubic Yards

Roof Deck Area

~1,262 Sq Ft

Plan HG-1531 (1,040 Sq Ft (26x40) 3 Bed 2 Bath Duplex / Multi-Gen Floor Plan (STC-60 Mirrored Acoustic Party-Wall Duplex)) is an IRC R304/R310-vetted duplex / multi-gen blueprint engineered around a 40'-0" × 26'-0" structural grid (1,040 sq ft base footprint, 0.65:1 Square-Bay Proportion). Configured on the STC-60 Mirrored Acoustic Party-Wall Duplex topology, this layout delivers 1,040 sq ft of conditioned residential living area and 240 sq ft of covered outdoor porch deck.

Inside the conditioned envelope, the floor plan is organized into 8 distinct architectural zones: UNIT A SUITE (12'-0" × 11'-6", 138 sq ft), UNIT A BATH (8'-0" × 11'-6", 92 sq ft), UNIT A LIVING (12'-0" × 14'-6", 174 sq ft), UNIT A KITCHEN (8'-0" × 14'-6", 116 sq ft), UNIT B BATH (8'-0" × 11'-6", 92 sq ft), UNIT B SUITE (12'-0" × 11'-6", 138 sq ft). Plumbing rough-ins are consolidated across UNIT A BATH, UNIT A KITCHEN, UNIT B BATH, UNIT B KITCHEN to minimize sub-slab trenching and manifold pipe runs. Sleeping quarters (UNIT A SUITE at 138 sq ft; UNIT B SUITE at 138 sq ft) are acoustically buffered from the primary living core and positioned on exterior elevations for code-compliant egress glazing.

From a builder takeoff standpoint, the 40' clear-span width utilizes 2x6 exterior + double-stud insulated acoustic party wall bearing on 132 linear feet of 6" exterior wall framing (~152 framing studs/posts) and 132 linear feet of interior partitions. The 5:12 architectural shingle or standing seam metal hip/gable requires approximately 1,262 sq ft of roofing material (16 roofing squares), while the monolithic concrete slab w/ dual sewer/water stub-outs pours at an estimated 21 cubic yards of 4,000-PSI concrete.

Frequently Asked Questions • Plan HG-1531

Building costs, foundation specs, egress & CAD customization questions

How much does it cost to build the 40x26 1,040 Sq Ft (26x40) 3 Bed 2 Bath Duplex / Multi-Gen Floor Plan (STC-60 Mirrored Acoustic Party-Wall Duplex) (HG-1531)?

Based on current national residential construction data for duplex / multi-gen structures, the dried-in structural shell for Plan HG-1531 (1,040 sq ft base footprint) ranges from $42,000 to $54,000 ($40/sq ft baseline). A complete turnkey build—including the 21-yard concrete foundation, 132 linear feet of interior framing, MEP rough-ins for 2 bath(s), and interior finishes across 1,040 sq ft of heated space—ranges from $157,000 to $191,000. Use the interactive Regional Cost Multiplier on this page to adjust for your local labor market and owner-builder sweat equity.

What are the exact room dimensions inside this 1,040 sq ft 3-bedroom layout?

Plan HG-1531 features 8 architecturally solved spaces inside its 40' × 26' footprint: UNIT A SUITE (12'-0" × 11'-6", 138 sq ft), UNIT A BATH (8'-0" × 11'-6", 92 sq ft), UNIT A LIVING (12'-0" × 14'-6", 174 sq ft), UNIT A KITCHEN (8'-0" × 14'-6", 116 sq ft), UNIT B BATH (8'-0" × 11'-6", 92 sq ft), UNIT B SUITE (12'-0" × 11'-6", 138 sq ft), UNIT B KITCHEN (8'-0" × 14'-6", 116 sq ft), UNIT B LIVING (12'-0" × 14'-6", 174 sq ft). Every habitable room meets or exceeds IRC R304 minimum area (70+ sq ft) and minimum horizontal dimension (7'-0"+) requirements.

Can this 40' × 26' floor plan be built with post-frame, red-iron steel, or 2x6 stick framing?

Yes. Because the outer envelope is engineered on an even 40'-0" × 26'-0" structural grid (132 LF perimeter) with clear-span 5:12 trusses, a local structural engineer or building kit supplier can adapt the blueprint for 2x6 Exterior + Double-Stud Insulated Acoustic Party Wall, conventional 2x6 stick framing at 16" o.c., laminated post-frame columns at 8' o.c., or structural insulated panels (SIPs).

What files are included in the free CAD blueprint download for Plan HG-1531?

Downloading Plan HG-1531 provides the high-resolution scalable vector floor plan (.SVG) with crisp architectural lineweights, exterior dimension strings (40'-0" × 26'-0"), room-by-room callouts, door swing arcs, and window schedules, plus instant browser printing for contractor bidding and preliminary municipal zoning review.