How Bilby works
House package prices and options
The house needs an actual package price
Bilby takes the house package price from a supplier or the user. It does not invent a purchase price from the house builder’s shape, colour or footprint. Until a real price is supplied, the house category can remain incomplete even when other costs have reference estimates. Options, delivery, assembly and completion are separate only to the extent that the package does not already cover them.
Turnkey is a scope statement
A house supplier’s turnkey or completion description controls which work remains. Bilby can mark specific cost types included in the package. Confirmed turnkey scope suppresses separate completion charges; confirmed non-turnkey scope allows applicable completion estimates. When completion scope is unknown, completion is provisionally assigned to the package pending confirmation rather than automatically added in full. The package price itself may still omit foundation, site works or fees. Read the contract instead of assuming that every supplier uses the same meaning of turnkey.
Price, scope and option inputs
The floor area used for a fallback is a quantity assumption, not an independent valuation of the house.
| Input | Unit | Origin |
|---|---|---|
| Package price | SEK | Supplier or saved user price |
| Turnkey/completion scope | status | Supplier information/user confirmation |
| Included cost types | scope | Contract reconciliation |
| Option percentage | % | User selects 5, 10 or 15 |
| House floor area | m² | Project quantity or editable reference default |
Two distinct option allowances
The option controls can set 5%, 10% or 15% of the actual effective package price, rounded to whole kronor. The saved percentage reason lets the amount follow a changed package price; removing or assigning the package elsewhere makes this percentage-based amount zero. This is a user-selected planning reserve, not the low/expected/high method. The independent national fallback for unspecified options is floor area × 250/750/2,000 SEK/m². Use one method for the same upgrades, or replace it with an actual scoped option quote. Other house costs likewise require separate identified scope rather than duplicating completion.
Illustrative supplier package
A fictional package priced at 2,500,000 SEK with a selected 10% options reserve adds 250,000 SEK. A new package price of 2,600,000 makes that same percentage reserve 260,000. In a separate 150 m² reference example, options are 37,500/112,500/300,000 SEK. Do not add both the 10% reserve and the full area-based allowance for the same undecided upgrades. The visual model does not determine either actual supplier package price.
A known price can still have unknown scope
An exact package amount does not prove that every installation, transport or optional finish is included. References use scenario specifications, while an accepted fixed quote may display the same amount across the range. Missing package price remains missing; a budget target cannot fill it. Check VAT, validity, completion level, foundation responsibility and change orders with the supplier, then use the budget’s inclusion and manual-price controls to reconcile them.
Price ownership and method date
Code reviewed 18 October 2026; option reference research dated 16 September 2026. The accepted supplier price and specification are the primary project evidence. Konsumentverket’s guidance on building a house provides consumer-contract context; it does not validate Bilby’s option percentages or area rates. Those reserves are Bilby planning assumptions.
The review date covers this explanation and its implemented method. Price and data dates are stated separately in the article.