Deck configurator: design in 3D, get the exact materials and cost
Kavandy does not multiply your area by a price per square metre. It builds your deck as a 3D model, part by part, and counts every board, joist, bearer, footing and screw from it – so the order, the cutting plan and the cost match what you will actually build.
What it does
- Calculated from the model. Every board, joist, bearer, footing and screw exists as a real part in the 3D model. Quantities and price are counted from those parts, not from area × a price per square metre.
- A cutting plan from stock lengths. The order says how many 3.0 / 3.6 / 4.2 / 5.4 m lengths to buy and how to cut each, with the offcut percentage.
- A load check on the frame. Board, joist, bearer and post spans are checked for a 2.5 kN/m² imposed load, with a one-click fix where something does not carry.
- Real materials. Treated pine, thermo pine, larch and WPC composite; C24 frame timber; five kinds of foundation.
- Step-by-step 3D build. The model goes together part by part in buildable order, with instructions and a checklist for each stage.
- Build video and AI photo. A short construction video and a photorealistic image that keeps the configured scale and viewpoint.
- Your real plot on a map. Draw on a map and set dimensions exactly; in Estonia parcel boundaries and building footprints come from open data.
- PDF and Excel. Drawings, a building guide, the cutting plan and the materials list as files to download.
What you can design
- Decks and terraces: any outline or a ready-made shape (rectangle, L, U, T, a bay, split levels); straight, diagonal, framed, herringbone and chevron boards; planters; railings; steps; a pergola or roof; sloping ground.
- Fences and gates: a fence line drawn in runs, each in its own style, with posts, footings, gates and a wind check.
- Garden rooms, saunas and sheds: timber-framed or laid in blocks, with foundation, roof, openings, cladding, cut list and build plan.
- Gazebos, pavilions and shelters: square, hexagonal or octagonal, with a choice of roofs and sides.
What a deck costs: sample figures
A 4 × 5 m (20 m²) deck, 45 cm high, on concrete blocks, with straight boards:
| Decking | Materials in all | € per m² |
|---|---|---|
| Treated pine 28×120 | ~€1,700 | ~85 |
| Thermo pine 26×117 | ~€2,140 | ~107 |
| Larch 28×120 | ~€2,260 | ~113 |
| WPC composite 24×140 | ~€2,500 | ~125 |
The same deck in treated pine at other sizes:
| Size | Area | Materials in all |
|---|---|---|
| 3 × 4 m | 12 m² | ~€1,050 |
| 4 × 4 m | 16 m² | ~€1,390 |
| 4 × 5 m | 20 m² | ~€1,700 |
| 4 × 6 m | 24 m² | ~€1,890 |
| 5 × 6 m | 30 m² | ~€2,180 |
| 5 × 8 m | 40 m² | ~€2,900 |
Sample prices at Kavandy’s default price list (October 2026) for the set-up described: 450 mm high, straight boards, joists at 500 mm, no steps or railing. Labour is not included. The real price depends on the supplier and the choices made.
What it works out for a 4 × 5 m deck
- Decking and fascia: 32 rows of 28×120 boards; buy 15 × 4.2 m + 26 × 3.6 m + 9 × 3.0 m, 2.9% offcut.
- Joists: 11 of C24 50×100. Bearers: 4 of C24 50×150 in four rows.
- Foundation: 20 concrete blocks with posts.
- Screws: 768 deck screws (about 38 per m²), plus fascia and frame screws, brackets and anchor plates.
How to build it: the terrace planner and building steps.
Frequently asked questions
How much does a 20 m² deck cost to build?
Materials for a 4 × 5 m deck (45 cm high, concrete blocks on gravel, straight boards) come to about €1,700 in treated pine, €2,150 in thermo pine, €2,250 in larch and €2,500 in WPC composite at Kavandy’s sample prices – roughly €85–125 per m². Steps and a railing add about €750. Labour is extra. For an exact figure with your own dimensions use the Kavandy configurator.
How many joists and boards does a 4 × 5 m deck need?
With straight boards and joists at 500 mm: 11 joists (50×100), 4 bearers (50×150), 20 footings and 32 rows of 28×120 boards – ordered as 15 × 4.2 m + 26 × 3.6 m + 9 × 3.0 m including the fascia – and 768 deck screws. At 400 mm joist spacing: 14 joists and 960 screws.
What joist spacing should a deck have?
About 21 times the board’s thickness for timber: up to about 590 mm for a 28 mm board and 545 mm for 26 mm; up to 400 mm for composite. 500 mm is the usual choice, and 400 mm for diagonal or herringbone boards, which span 1.41 times further between the same joists.
How many screws per square metre of decking?
Two at every crossing of a board and a joist: about 38 per m² with 120 mm boards on joists at 500 mm, about 48 at 400 mm and about 35 at 600 mm, plus the fascia and frame screws.
Is Kavandy free?
Yes. Designing, the 3D view, exact quantities, the price, the cutting plan and the PDF and Excel files are free.
Does it work outside Estonia?
The configurator is in English and Estonian and works in metric units anywhere. The map’s parcel boundaries and building footprints come from Estonian open data; elsewhere you set the dimensions directly.