Bathroom Renovation Feasibility Calculator | Emerge Design and Build
Emerge Design and Build

Bathroom renovation feasibility estimate

Use this calculator to create an early budget range for a bathroom renovation based on the information currently known. It is designed for feasibility only, helping you understand likely cost drivers before a site visit, final selections, or a formal fixed-price proposal. The estimate updates as you adjust the bathroom size, fixtures, finishes, consent requirements and known condition allowances.

Your bathroom details

Bathroom dimensions

Enter the approximate internal room size. These measurements drive floor area, perimeter-based items, and full-height wall tiling where selected.

Enter the approximate internal length of the room.
Enter the approximate internal width of the room.
Used for full-height wall tiling calculations.
Consent and documentation

Some bathroom upgrades require additional documentation or a building consent, particularly when converting from a non-tiled bathroom to a tiled wet area. This allowance is included only when selected.

Includes a provisional minor works consent, basic documentation and consent administration allowance. Final consent requirements must be confirmed for the specific property and scope.
Existing condition allowances

Select these only where there is known or likely damage. They add provisional allowances for common issues that are often confirmed after demolition or linings are removed.

Adds a provisional allowance for repairing soft, damaged or water-affected flooring/subfloor areas.
Adds a provisional allowance for damaged framing or wall timber discovered once existing linings are opened up.
Wall and ceiling linings

Choose whether the estimate should allow for replacing wet-area wall and ceiling linings. Existing linings may still need assessment on site.

Includes replacement Aqua GIB/wet-area wall linings based on the bathroom perimeter.
Includes replacement ceiling lining based on the calculated ceiling/floor area.
Included fixtures

Select the fixtures that are included in the proposed renovation. These allowances cover the current baseline fixture type and installation logic, adjusted by the selected specification level.

Includes a standard acrylic shower allowance. Tiled shower selections are added separately on top of this base shower cost.
Baseline allowance is for a standard 900mm vanity and associated installation.
Includes replacement toilet works based on the current bathroom cost model.
Includes a standard bath allowance and installation based on the current bathroom cost model.
Finishes

Select the main floor and wall finish assumptions. Tiled floor and wet-area options include waterproofing within the rate.

Uses the baseline vinyl floor finish allowance.
Replaces the vinyl allowance and calculates the tiled/waterproofed floor from the room floor area.
Only one floor finish can be selected. Floor tiling is calculated from length × width.
No wall/shower tiling allowance is added.
Adds a separate shower tiling/waterproofing allowance based on a standard feasibility shower area.
Calculates full-height wall tiling from wall perimeter × ceiling height.
Waterproofing is included inside these tiling allowances. Wall/shower tiling shows as its own cost category when selected.
Specification level

Choose the expected level of fixture and finish selection. This changes selected fixtures and finishes only; it does not increase demolition, consent, linings, painting, trims or condition allowances.

Uses the baseline fixture and finish allowances.
Allows for a moderate uplift to selected fixtures and finishes.
Allows for a higher level of fixture and finish selections.
Only one specification level can be selected. The multiplier is applied internally only to selected fixture and finish categories.
Estimate display settings

Choose whether the estimate is displayed including GST and how the final figures are rounded. The feasibility range is fixed at ±5%.

The feasibility range is fixed at ±5%.
Key assumptions

This feasibility estimate assumes a bathroom renovation within the existing room footprint and generally within the same layout. It does not include underfloor heating, major plumbing relocation, major electrical upgrades, asbestos removal, structural work, or hidden damage unless selected as a condition allowance. Waterproofing is included within tiled floor and tiled wet-area selections where selected. Delivery, preliminary setup and business overheads are included internally and are not shown as separate client-facing line items. The feasibility range is fixed at ±5%.