Plan HG-1147•Modular / Prefab Cottage•24' × 20' Footprint

482 Sq Ft (20x24) 1 Bed 1 Bath Modular / Prefab Cottage Floor Plan

482 sq ft heated living • 1 Bedroom, 1 Bath • Free 2D CAD Blueprint (.SVG)

Download Free CAD (.SVG)

Room Dimensions & Zones

24' × 20' Shell

PRIMARY BEDROOM

131 sq ft

14'-6" × 9'-0"

BATH & LAUNDRY

86 sq ft

9'-6" × 9'-0"

GREAT ROOM & DINING

160 sq ft

14'-6" × 11'-0"

KITCHEN & ISLAND

105 sq ft

9'-6" × 11'-0"

Build Cost Estimator

Estimated Cost to Build (24' × 20' Modular / Prefab Cottage)

Region:

Shell / Building Kit

$21,000 – $26,500

Framing package, roof trusses & exterior shell for 480 sq ft base.

Owner-Builder

$50,500 – $66,500

Saves ~$22,500 by managing local slab & interior trades.

Turnkey Builder

$73,000 – $89,000

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

Est. Monthly Payment

$420 / mo

$64,800 financed (30-Yr)

Down Payment:20%

Interest Rate:6.75%

Free Vector CAD Blueprint • Plan HG-1147

Download 24' × 20' Modular / Prefab Cottage 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 (11 yd³), roof surface (~582 sq ft), wall framing & architectural notes

Building Package	Specification	Quantity	Est. Range
Structural Shell & Trusses	24'×20' Factory-Engineered 2x6 Modular Box System w/ Marriage Wall	480 sq ft shell kit	$21,000 – $26,500
Concrete Slab & Grade Beams	Stem Wall Crawlspace or Full Perimeter Foundation	11 Cubic Yards (4,000 PSI)	$4,750 – $6,250
Roofing & Underlayment	Hinged 5:12 Architectural Shingle or Metal Gable Roof (5:12 Pitch)	7 Roofing Squares (700 sq ft)	$2,940 – $4,760
Closed-Cell Spray Foam / Insulation	3" Closed-Cell Wall & Roof Deck Thermal Envelope (R-21 to R-38)	4,164 Board Feet	$5,621 – $7,703
Windows & Exterior Doors	Low-E Argon Black Architectural Glazing + 36" Fiberglass Entry	6 Windows • 3 Doors	$5,100 – $7,980
HVAC & Multi-Zone Mini-Split	High-SEER2 Heat Pump / Ductless Mini-Split System	1.5 Ton (18,000 BTU/hr)	$3,900 – $6,150

Exterior Perimeter

88 Linear Ft

Interior Partitions

~63 Linear Ft

Est. Concrete Slab

11 Cubic Yards

Roof Deck Area

~582 Sq Ft

Plan HG-1147 (482 Sq Ft (20x24) 1 Bed 1 Bath Modular / Prefab Cottage Floor Plan) is an IRC R304/R310-vetted modular / prefab cottage blueprint engineered around a 24'-0" × 20'-0" structural grid (480 sq ft base footprint, 0.83:1 Square-Bay Proportion). Configured on the Consolidated Wet-Wall + Open Great Room topology, this layout delivers 482 sq ft of conditioned residential living area and 87 sq ft of covered outdoor porch deck.

Inside the conditioned envelope, the floor plan is organized into 4 distinct architectural zones: PRIMARY BEDROOM (14'-6" × 9'-0", 131 sq ft), BATH & LAUNDRY (9'-6" × 9'-0", 86 sq ft), GREAT ROOM & DINING (14'-6" × 11'-0", 160 sq ft), KITCHEN & ISLAND (9'-6" × 11'-0", 105 sq ft). Plumbing rough-ins are consolidated across BATH & LAUNDRY, KITCHEN & ISLAND to minimize sub-slab trenching and manifold pipe runs. Sleeping quarters (PRIMARY BEDROOM at 131 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 24' clear-span width utilizes factory-engineered 2x6 modular box system w/ marriage wall bearing on 88 linear feet of 6" exterior wall framing (~111 framing studs/posts) and 63 linear feet of interior partitions. The 5:12 hinged 5:12 architectural shingle or metal gable roof requires approximately 582 sq ft of roofing material (7 roofing squares), while the stem wall crawlspace or full perimeter foundation pours at an estimated 11 cubic yards of 4,000-PSI concrete.

Frequently Asked Questions • Plan HG-1147

Building costs, foundation specs, egress & CAD customization questions

How much does it cost to build the 24x20 482 Sq Ft (20x24) 1 Bed 1 Bath Modular / Prefab Cottage Floor Plan (HG-1147)?

Based on current national residential construction data for modular / prefab cottage structures, the dried-in structural shell for Plan HG-1147 (480 sq ft base footprint) ranges from $21,000 to $26,500 ($44/sq ft baseline). A complete turnkey build—including the 11-yard concrete foundation, 63 linear feet of interior framing, MEP rough-ins for 1 bath(s), and interior finishes across 482 sq ft of heated space—ranges from $73,000 to $89,000. 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 482 sq ft 1-bedroom layout?

Plan HG-1147 features 4 architecturally solved spaces inside its 24' × 20' footprint: PRIMARY BEDROOM (14'-6" × 9'-0", 131 sq ft), BATH & LAUNDRY (9'-6" × 9'-0", 86 sq ft), GREAT ROOM & DINING (14'-6" × 11'-0", 160 sq ft), KITCHEN & ISLAND (9'-6" × 11'-0", 105 sq ft). Every habitable room meets or exceeds IRC R304 minimum area (70+ sq ft) and minimum horizontal dimension (7'-0"+) requirements.

Can this 24' × 20' floor plan be built with post-frame, red-iron steel, or 2x6 stick framing?

Yes. Because the outer envelope is engineered on an even 24'-0" × 20'-0" structural grid (88 LF perimeter) with clear-span 5:12 trusses, a local structural engineer or building kit supplier can adapt the blueprint for Factory-Engineered 2x6 Modular Box System w/ Marriage 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-1147?

Downloading Plan HG-1147 provides the high-resolution scalable vector floor plan (.SVG) with crisp architectural lineweights, exterior dimension strings (24'-0" × 20'-0"), room-by-room callouts, door swing arcs, and window schedules, plus instant browser printing for contractor bidding and preliminary municipal zoning review.