Guides
How to calculate materials for each stage of a build: the formula, the waste, a worked example and indicative prices. Every topic opens in Baukit too.
Planning
Shell
Concrete for 100 m² house foundations: formula and example
Strip footings for a 10 × 10 m house (60 × 40 cm) take about 11.5 m³ of concrete; with waste, order 12.5 m³. Formula, waste, truckloads and an example.
How many blocks for a 100 m² house? Porotherm, Ytong, Solbet and Silka
How much EPS for a 100 m² house? Packs with waste
Roof
How much mineral wool for an attic? Rolls for a gable roof
For 141 m² of slopes and ceiling, buy about 33 rolls of 15 cm wool and 25 of 10 cm (25 cm in all). Insulated area, vapour barrier and WT 2021 thickness.
How to calculate the area of a gable or hip roof
A 14.25 × 8.65 m roof at 42° has about 166 m²: divide the roof plan by the cosine of the pitch. Formula, covering waste, membrane, flashings, example.
Every guide ends with a number you can take to the builders' merchant.
The formula, the allowance, a worked example and indicative prices (as of October 2026). Then one click opens the same example in the editor.
Finishing
Plasterboard suspended ceiling: how many CD and UD profiles, hangers and boards?
Suspended ceiling calculator: a 4 × 5 m ceiling takes about 18 CD profiles of 4 m, 6 UD, 30 hangers and 7 sheets. Spacings per system tables.
How much laminate flooring? Counting packs with waste
How many tiles to buy? Formula, 10% or 15% waste, example
How much paint per m² of wall? Formula and coverage table
Stud partition wall: how many boards, profiles and screws?
