How Bilby works
House completion and installations
Completion is a subtotal of remaining work
The house completion estimate combines applicable finishes and installations that are outside the supplier package. It is a parent subtotal: the kitchen, bathroom and installation details explain that total and are not added on top again. Confirmed turnkey scope removes the duplicate completion contribution. If scope is unknown, the budget provisionally assigns completion to the package pending confirmation.
Scope boundaries inside the house
Exterior completion is ordinary painting/minor finish on a supplied facade, not buying the facade twice. Interior shell means partitions/lining/joinery outside the delivered kit. Kitchen includes ordinary appliances, basic wardrobes and fitting; bathroom fit-out assumes prepared service rough-ins. Heating plant and internal distribution are distinct from bathroom fixtures and from heating already embedded in a foundation. Ventilation, electrical work and dry-room floor/paint finishes have their own scopes. An optional fireplace/chimney is separate from the standard completion subtotal.
Different work uses different quantities
Do not substitute footprint for total floor area in a multi-storey house. Dry-room finish area must avoid bathrooms already priced separately.
| Input | Unit | Origin/default |
|---|---|---|
| Floor area | m² | Project or editable 150 |
| Facade area | m² | Project or assumed 180 |
| Bathrooms | count | Project or assumed 2 |
| Dry finish area | m² | Project or assumed 150 |
| Kitchen/heating/fireplace | package | Ordinary fixed reference |
| Supplier inclusions | scope | Contract/user confirmation |
Component formulas
National reference components use the following low/expected/high rates. The parent sums applicable child amounts after package exclusions, retaining project-specific child prices before references. Minimum charges matter for small houses. Standard FTX ventilation must not duplicate ventilation already provided by an exhaust-air heat-pump package.
| Scope | Formula low / expected / high |
|---|---|
| Exterior | Facade m² × 300 / 550 / 950 |
| Interior shell | Floor m² × 900 / 1,600 / 2,800 |
| Kitchen / appliances / wardrobes | 90,000 / 180,000 / 350,000 fixed |
| Bathroom | Count × 120,000 / 200,000 / 330,000 |
| Heat-pump plant | 100,000 / 140,000 / 220,000 fixed |
| Plumbing/heating distribution | Floor m² × 450 / 750 / 1,200 |
| FTX ventilation | max(60,000 / 80,000 / 120,000; floor m² × 500 / 700 / 1,100) |
| Electrical | max(65,000 / 85,000 / 130,000; floor m² × 550 / 850 / 1,300) |
| Dry floor/paint finish | Dry m² × 700 / 1,200 / 2,000 |
| Optional fireplace/chimney | 40,000 / 65,000 / 110,000 fixed |
Illustrative non-turnkey completion
Take a fictional 150 m² house, 180 m² facade, two bathrooms and 130 m² dry finishes, with none of these scopes supplied. Expected components are 99,000 exterior + 240,000 interior + 180,000 kitchen + 400,000 bathrooms + 252,500 plumbing/heating + 105,000 ventilation + 127,500 electrical + 156,000 finishes = 1,560,000 SEK. Low/high are 935,000/2,621,000. The optional fireplace would add 40,000/65,000/110,000. If the kitchen is already included, its 180,000 expected amount must leave the completion subtotal.
Match specifications before comparing quotes
These are broad consumer installation scenarios, not a room-by-room specification or a statistical interval. The house builder does not lay out rooms or select actual kitchen products. Missing quantities stay disclosed assumptions. Premium fixtures, unusual technical systems and supplier overlap require review. A quote may include work spread across several reference headings; reconcile its scope before overriding only one child row.
Product and installation evidence
Code reviewed 18 October 2026; national reference research 16 September 2026. IKEA’s kitchen price examples and installation scope help separate products from fitting. Ventilation.se’s FTX kits are equipment evidence, not a complete installed-house quote. Bilby combines such anchors with modelled labour and scope.
The review date covers this explanation and its implemented method. Price and data dates are stated separately in the article.