3 free starting designs

Lean-to greenhouse plans

3 free lean-to plans: one roof slope hung from a 2x6 ledger on a sunny house wall, the low front wall glazed down to the base and the vents up high where the heat collects. Each size reads depth from the house by length along it.

Customize the 6x12, free Compare the 3 sizes

A wooden lean-to greenhouse against the south wall of a house, roof vents open by the house wall

Plans: 3
Floor: 72 to 96 sq ft
Materials: $2,766 to $3,298
Planner checks: All pass at 20 psf

Every size, drawn by the designer

Pick a lean-to size.

Each one is a full starting plan: framed, checked at 20 psf of snow and priced. Switch the view to see the frame or the dimensions.

The 6x12 lean-to greenhouse, drawn by the designer

Drawn by the designer from this plan

6x12

6x12 lean-to greenhouse

Against a south wall: one bench along the front, vents up high by the house.

Floor: 72 sq ft
Roof: 4/12 lean-to
Front wall: 6'
On the house: 8' 5-3/4"
Vents: 3 roof, 4 side
Benches: 1 x 24"

10 of 10 planner checks passed

Materials about $2,766, before tax and delivery

Customize the 6x12, free View the 6x12 plan

Side by side

The 3 lean-to plans compared.

Plan	Roof	Floor	Front wall	Height	Glazing	Vents	Benches	Materials	Checks
6x126x12 lean-to greenhouse	Lean-to	72 sq ft	6'	8' 2-1/16"	8 mm twin-wall	3 roof, 4 side	1 x 24"	$2,766	10 of 10
6x166x16 lean-to greenhouse	Lean-to	96 sq ft	6'	8' 2-1/16"	8 mm twin-wall	4 roof, 6 side	1 x 24"	$3,298	10 of 10
8x128x12 lean-to greenhouse	Lean-to	96 sq ft	6'	8' 10-1/16"	8 mm twin-wall	4 roof, 6 side	2 x 24"	$3,204	10 of 10

Each row is the starting plan as drawn, at 20 psf of snow. Materials are the greenhouse itself, before the gravel bed, tax and freight.

How to choose

What leaning on the house gives and takes.

One slope and one wall borrowed from the house. Here is what that means on each plan, in the designer's own numbers.

01Height
Low at the front, high on the house.
The roof rises from the front wall to a ledger on the house wall. On these plans the front wall is 6' to the plate and the ledger top sits 8' 5-3/4" above grade at the 4/12 slope, higher on the deeper plans.
How to read the chart: each pair of bars is one plan, the front wall to the plate top and the ledger top on the house. Your house wall needs that much clear height under the eaves and above any window or door you build against.
Ledger on the houseFront wall
- 6x128' 5-3/4"6'
- 6x168' 5-3/4"6'
- 8x129' 1-3/4"6'
02Vents
Vents up high, by the house wall.
Hot air collects under the high side, so the roof vents sit by the ledger. We draw roof vents of at least 20% of the floor and side vents of 20%, the ASABE figures cited by the extension guides.
Every plan here meets both figures as drawn, without a fan. The 8x12 has only one long glazed wall and not enough stud bays in it, so the designer puts 2 of its 6 side vents in the end walls; its plan page shows where.
Roof vents drawnNeeded
- 6x1216.9 sq ft14.4 sq ft
- 6x1622.5 sq ft19.2 sq ft
- 8x1222.5 sq ft19.2 sq ft
03Cost
Cheaper than freestanding, by one wall.
On the same 96 sq ft, our 8x12 lean-to came to $3,203.60 in materials against $3,813.80 for the 8x12 freestanding gable. The house wall replaces one glazed wall, its framing and its sheets.
The basis: both are our starting plans as drawn, at 20 psf of snow, priced from the same table. A different size, store or week can change the gap.
- 8x12 lean-to$3,204
- 8x12 gable$3,814
04The house wall
Ask before you fix the ledger.
The ledger is fixed into the wall framing and flashed above, and how depends on your wall: siding over studs, brick or block. The planner does not check that connection, and it flags it on every lean-to plan.
A lean-to against a house is also part of the house for many building departments, with its own permit rules. Ask yours before you order.

What they cost

$2,766 to $3,298 in materials.

Each plan's shopping list, priced line by line, before sales tax, freight and tools. The bar is the greenhouse itself; the gravel bed under it is estimated apart.

Lowest: $2,766, 6x12
Highest: $3,298, 6x16
Per sq ft of floor: $33.37 to $38.42
Hours, our estimate: 34 to 65 h

Excluded: tax, freight, labor, permits, tools

Prices differ by store and by week: the greenhouse cost calculator takes your own store's prices.

Greenhouse materials for each lean-to plan

6x12$2,766+ est. $47 to $159 gravel bed
6x16$3,298+ est. $60 to $205 gravel bed
8x12$3,204+ est. $56 to $186 gravel bed

The $29 builder's plan

Free to plan. $29 to build from.

Every plan above is free to open, check and price. The builder's plan is drawn from the greenhouse you finish, for one payment. These are real sheets from the 36-sheet plan for the 8x12 gable greenhouse.

Free

The design in 3D, and every change you make to it
Every planner check, with its rule and its source
The materials list priced line by line
A summary PDF of the design and its checks

$29 once

Every wall framed, each stud and girt dimensioned from the corner
Every polycarbonate sheet numbered, with its cut and the stock sheet it comes from
The cut list, every cut assigned to a store board
Vents or the exhaust fan, the door and the benches, each on its own sheet
The shopping list with store prices and the build, phase by phase

Customize the 6x12, free

You check out in the designer, with your design loaded. If the plan has an error, we fix it or refund you within 30 days. Guarantee terms.

Real sheets from the 36-sheet sample plan for the 8x12 gable greenhouse

17Wall framing
23Sheet layout
11Cut list
33Build sequence

Questions

Anything else? Write to us or read the questions about all plans.

Questions about lean-to greenhouse plans

A greenhouse with a single-slope roof that leans against a house or garage wall. Its high side rests on a ledger fixed to that wall, so it has three glazed walls instead of four and shares some heat with the house.

A freestanding greenhouse with a gable roof whose two slopes are the same length, with the ridge in the middle. Our freestanding plans are this type, from 6x8 to 12x20.

Clemson suggests at least 6 x 10 ft for a lean-to. Our lean-to plans run from 72 to 96 sq ft; count the bench length you want and how far your sunny wall runs, then pick or change a size in the designer.

Yes: the 3 plans on this page are free, with no account. Each one opens in the designer, where you can change the depth, the length, the vents and the benches, and download a free summary PDF.

Start from a plan that fits your wall and your bench, then build it in order: the gravel bed and base, the wall frames, the roof frame on its ledger, the door and benches, the polycarbonate, and last the vents. Each lean-to plan page shows those phases drawn for that size, and the guide to building a greenhouse explains each one.

Other ways to browse

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