How Bilby works
Garden beds, growing boxes and planting
Soil preparation and plants are separate
A garden bed prices prepared planting soil; a growing box prices the timber frame and soil. Flowers or mixed planting are added only when selected. The planner sends bed preparation and plants to landscaping and boxes to outdoor areas. Overlapping bed geometry is resolved before area is priced.
What the options include
The native unplanted-bed model includes shallow working, an ordinary 0.20 m soil layer, final grading and shared setup. The fallback assumes roughly 0.25 m growing soil. Neither includes selectable decorative edging: choosing an edge changes appearance but currently adds no edging price. Native boxes are ordinary two-course timber collars with 0.25 m useful soil depth. Plants, irrigation, lids and trellises are outside the box base. Optional irrigation and garden design are separate budget allowances, not automatic consequences of drawing a bed.
Area, perimeter and soil
A measured outline does not establish the plant mix or a specialist soil specification.
| Input | Unit | Origin |
|---|---|---|
| Net bed area / bed width | m² / m | Smoothed planner geometry |
| Box footprint and perimeter | m² / m | Width and depth |
| Box soil volume | m³ | Area × assumed 0.25 m |
| None / flowers / mixed plants | choice | User |
| Irrigated area | m² | Editable assumption if separately added |
Native preparation and fallback
Native bed pricing is max(minimum, setup + area × rate): low/expected/high setup 4,000/7,000/11,000 SEK, rates 250/450/700 SEK/m² and minimums 8,000/12,000/18,000. It supports normal 5–100 m² packages and 1–4 m widths. The fallback uses 200/350/600 SEK/m² with 2,000/3,500/6,000 minimums. Flower planting adds 150/300/600 SEK/m²; mixed planting adds 250/550/1,000. A native box uses a size-tier frame amount plus soil at 800/1,300/2,000 SEK/m³ and one shared delivery/setup amount per package. Larger bespoke boxes fall back to fixed handling + perimeter-priced frame + area-priced separator + soil volume. These alternate paths are never summed together.
Growing-box and irrigation coefficients
For native boxes, the first tier (area up to 1.2 m² and longest side up to 1.3 m) uses frame amounts 500/1,000/2,000 SEK; the second (up to 2.5 m² and 2.4 m) uses 1,000/2,000/4,000. Shared setup is 500/1,000/2,000, counted once, plus the native soil rate above. The alternative reference box formula is fixed 1,000/2,000/3,800 + perimeter × 150/250/450 + area × 20/40/80 + soil m³ × 1,200/1,800/3,000. For optional irrigation, multiply irrigated m² by 70/130/230, applying minimums 12,000/20,000/35,000 SEK. Irrigation does not include a new water supply or well.
Illustrative planted bed
A fictional 20 m² bed, 2 m wide, uses native preparation: 9,000/16,000/25,000 SEK. Flowers add 3,000/6,000/12,000, giving 12,000/22,000/37,000 SEK. Decorative edging adds zero in the current calculation and therefore remains an unbudgeted purchase. Separately, a reference-formula illustration for a 2 × 1 m box with perimeter 6 m and 0.5 m³ soil gives 2,540/4,480/8,160 SEK; that example deliberately uses the reference formula, not the native tier.
Soil logistics and optional work
Ranges are modelled installed scopes, not plant-by-plant quotes. Garden design is a separate 8,000/20,000/50,000 SEK reserve. Irrigation uses area rates with minimum installation charges. Removing old vegetation, deep soil replacement and specialist planting must be checked separately. A supplier quote should identify what is included so preparation is not bought twice. Missing geometry remains an editable assumption or a provisional warning; changing a bed colour does not establish a new labour operation.
Method and product evidence
Code reviewed 18 October 2026; native bed/box models V2 and September 2026 national references. Plantagen’s growing collars and soil range support material scope only. Delivery, professional preparation and planting coefficients are Bilby allowances.
The review date covers this explanation and its implemented method. Price and data dates are stated separately in the article.