homestead.fyi / COLDFRAME

3x6 Cold Frame

A 3 x 6 ft cold frame of ground-contact 2x6s, sloped to the front, with a hinged lid covered in plastic.

Draft plan, generated from the model. Not yet build-tested.
72 x 36 inSize
11 to 16 inHeight
9°Lid pitch
3 to 5 hrBuild time
$223.34Materials

Drawings All dimensions in inches

3D viewfinished
3D view
3D view, framingsiding and roof removed
3D view, framing
Front elevation
Front elevation 74 in 18 1/4 in
Right elevation
Right elevation 38 1/4 in 18 1/4 in
Plan viewfrom above
Plan view 74 in 38 1/4 in

Cut list: lumber Long-point lengths; angles noted

QtyStockLengthPartCut
12x474Lid rail frontlaid flat
12x474Lid rail backlaid flat
12x431 3/8Lid stile leftlaid flat
12x431 3/8Lid stile rightlaid flat
12x431 3/8Lid stile middlelaid flat
22x4 PT16 1/2Corner postinside the corner
22x4 PT11Corner postinside the corner
22x6 GC72Front boardon edge
32x6 GC72Back boardon edge

Cut list: sheet goods

PartStockSizeNote
Left side1/2 ply36 x 16 1/2top cut at the slope
Right side1/2 ply36 x 16 1/2top cut at the slope

Lumber cutting diagram Lengths chosen for the lowest cost; 1/8 in kerf, 1/2 in end trim

2x4 x 8 ft
Lid stile left 31 3/8Lid stile right 31 3/8Lid stile middle 31 3/8
2x4 x 8 ft
Lid rail front 74
2x4 x 8 ft
Lid rail back 74
2x4 PT x 8 ft
Corner post 3 16 1/2Corner post 4 16 1/2Corner post 1 11Corner post 2 11
2x6 GC x 8 ft
Front board 1 72
2x6 GC x 8 ft
Front board 2 72
2x6 GC x 8 ft
Back board 1 72
2x6 GC x 8 ft
Back board 2 72
2x6 GC x 8 ft
Back board 3 72

Sheet cutting diagrams Dashed = openings to cut out

Sheet 1: 1/2 in plywood, 4 x 8 ft
Left side36 x 16 1/2Right side36 x 16 1/2

Shopping list $223.34 checked / $0.00 estimated

ItemStoreQtyEachLineNote
2x4x8 stud, SPFHome Depot3$4.15$12.45see lumber cutting diagram
2x4x8 ground-contact pressure-treatedHome Depot1$4.68$4.68see lumber cutting diagram
2x6x8 ground-contact pressure-treatedHome Depot5$9.78$48.90see lumber cutting diagram
15/32 in (1/2 in) sheathing plywood, 4x8 sheetLowe's1$32.26$32.26see sheet cutting diagrams
6 mil greenhouse film, 20 x 25 ftWalmart Business1$83.99$83.99covers the lid; the rest is spare
Galvanized 6 in strap hinge, each (5-pack $32.99)Home Depot1$6.60$6.60lid
Exterior wood screws #9 x 2.5 in, 5 lb boxHome Depot1$29.97$29.97
Poultry staples 3/4 in, 1 lbSouthern States1$4.49$4.49
Total before tax$223.34
Filled dot: price read from a store listing on Oct 20, 2026. Hollow dot: estimate. Prices come from the master price list, so they change when it changes.

Build steps

  1. Cut the 2x6 boards and plywood sides. Level the ground and spread 2 in of gravel.
  2. Screw the back boards and then the front boards between the corner posts, with the posts inside the corners.
  3. Cut the two plywood sides with a 9° slope on top from the back height to the front height, and screw them to the posts and boards.
  4. Build the lid from four 2x4s laid flat with a center stile and screw the corners with 2.5 in screws.
  5. Staple 6 mil plastic over the lid and trim, or screw a 1x2 batten over the edge.
  6. Hinge the lid at the back with two hinges and set a notched prop stick so it can open 8 in for ventilation.

Before you start