How to estimate bath to shower conversion from scope to total in Australia

By Estimates editorial team · Published 2026-09-25 · Australia edition

This guide follows one existing bath alcove in Sydney, New South Wales. The matching itemised estimate and PDF show how the job brief becomes measured quantities and separate AUD amounts. The responsible role in this scenario is renovation contractor. Check the actual site, selected products, supplier figures and labour plan before issuing a client quote.

1. Define the measured job

Remove one bath and fit a shower in the same alcove, with a new base, wall finish, valve trim and screen allowance. Existing supply and drain positions remain. Measure the finished alcove on three sides, the wet-wall area and the drain location before selecting the base. Record the measurements and existing condition in the estimate before turning quantities into line items. The scope should make clear why this is a separate project from a broader renovation or maintenance quote.

Measure for this job: Measure the finished alcove on three sides, the wet-wall area and the drain location before selecting the base. Put that measured basis beside the relevant PDF lines so area, fitted length and product purchase quantities stay distinct.

2. Build a product and labour schedule

Keep the shower base, screen and finish tile as named allowances until the products are selected. This example has 7 distinct lines, including dust protection, bath and surround removal, shower base allowance. Use actual supplier prices and labour inputs for a customer job; the displayed amounts are fictional document inputs.

Choose before pricing: Keep the shower base, screen and finish tile as named allowances until the products are selected. The fixture separates dust protection, bath and surround removal and shower base allowance rather than hiding all work in one figure.

3. Sequence the work and handoffs

Confirm water shutoff, demolition, waterproofing inspection and curing time before promising a handoff date. Show which task depends on access, a selected product or another trade. If that dependency is still open, label the price preliminary and identify the information needed before a firm quote.

Plan the handoffs: Confirm water shutoff, demolition, waterproofing inspection and curing time before promising a handoff date. Note which stage needs access, a selected product or another trade before the next stage can be priced confidently.

4. Set a change boundary

Rot behind the surround or a drain that cannot align with the chosen base changes the work. The example excludes bathroom layout change, concealed structural repair or whole-room repainting. Record the discovery, agree the revised work and update the estimate before adding it to the job.

Change trigger: Rot behind the surround or a drain that cannot align with the chosen base changes the work. Record the revised task and quantity before it changes the amount your client sees.

Review the Australian job

Verify the existing water and waste connections, access and selected fittings on site. Assign any specialist work and check approval requirements that apply to the actual address.

The wet-wall preparation and waterproofing line uses 6.97 m². Keep the site measurement and supplier's selling unit together; a material purchase allowance can differ from installed coverage. The amounts are fictional AUD inputs, not current prices for Sydney, New South Wales or another location.

Worked project calculation

The paired PDF has 7 cost lines. For example, Shower base allowance is 1 each × A$965.20 = A$965.20; Wet-wall preparation and waterproofing is 6.97 m² × A$246.00 = A$1,714.62. Each amount comes from the stated quantity and unit rate, so you can trace the arithmetic back to the job scope.

Adding every exact-cent line gives A$7,194.83. The PDF uses a 0% tax input only to make its fictional arithmetic visible. Confirm the GST treatment that applies to the actual job and set your own markup before sharing a client quote. A fictional rate is a document input, not a market quote or a recommended selling price.

Scope and pricing boundaries

Remove one bath and fit a shower in the same alcove, with a new base, wall finish, valve trim and screen allowance. Existing supply and drain positions remain.

Outside this example: No bathroom layout change, concealed structural repair or whole-room repainting.

Separate product allowances, supply, installation, disposal and any specialist work where the actual project needs them. If access or a hidden condition changes, document the affected scope and agree a revised price instead of silently extending the base amount.

Before you send the estimate

• Measure the finished alcove on three sides, the wet-wall area and the drain location before selecting the base.
• Keep the shower base, screen and finish tile as named allowances until the products are selected.
• Confirm water shutoff, demolition, waterproofing inspection and curing time before promising a handoff date.
• Rot behind the surround or a drain that cannot align with the chosen base changes the work.

Check business and client details, address, dates, scope, units, line amounts and PDF notes. The bath to shower conversion PDF example shows how this fictional project is presented. Its short PDF note is not a substitute for the detailed exclusions above.

Questions about this estimate

Which quantity controls this bath to shower conversion estimate?

Measure the finished alcove on three sides, the wet-wall area and the drain location before selecting the base.

When should this bath to shower conversion quote be revised?

Rot behind the surround or a drain that cannot align with the chosen base changes the work. No bathroom layout change, concealed structural repair or whole-room repainting.

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