A modular partnership needs a written scope for design, approvals, factory work, transport, installation and aftercare. There is no standard split that applies to every project. Name the responsible business and the documents it must provide at each stage.
The agreement should also explain how the parties handle changes and disputed defects. Keep the customer's reporting contact clear, even when several businesses contribute to the home.
Agree the scope before the first project
A manufacturer may supply a module only, or provide a wider delivery and installation package. A builder may manage the complete project or a defined part of the site work. Confirm the actual arrangement before quoting to a customer.
The ABCB handbook discusses compliance considerations for prefabricated, modular and offsite construction. It does not establish who must perform each commercial task in your partnership.
Contract terms also need to respect applicable law. A responsibility table cannot remove statutory duties or applicable consumer guarantees.
Responsibility checklist
Use this table to allocate work. It is a checklist for an agreement, not an assumption that one party always owns a task.
| Workstream | What to agree in writing | Evidence to request |
|---|---|---|
| Product design | Who prepares drawings and approves changes | Current drawings and change approvals |
| Engineering | Who checks the module, foundations and interfaces | Engineering scope and site-specific reports |
| Planning approval | Who prepares and manages the application | Application scope and required supporting reports |
| Building approval | Who coordinates the certifier and inspections | Approval requirements and inspection records |
| Factory work | What is supplied and how it is checked | Supply schedule and quality records |
| Foundations and site work | Who prepares supports, access and the building area | Site scope and installation requirements |
| Transport | Who arranges the route, access and insurance | Transport plan and notice or permit conditions |
| Lifting and installation | Who provides equipment, labour and supervision | Installation method and handover records |
| Services | Who arranges water, wastewater and electrical connections | Trade scope and relevant certificates |
| Customer communication | Who provides updates and receives complaints | Named contacts and escalation process |
| Defects and warranty | Who investigates, coordinates repairs and handles claims | Warranty terms and defect-reporting process |
For NSW projects, DA means Development Application and CDC means Complying Development Certificate. Other jurisdictions use different planning and building pathways. Assign the application task without promising an approval outcome.
Resolve three common gaps
Changes beyond the standard design
A layout change can affect engineering, approvals, price and delivery timing. Ask who assesses the request and who approves the revised drawings. Record the cost and programme effects before manufacture proceeds.
Do not treat a sales conversation as approval for a structural change. The required engineering and certification checks still need to be resolved.
Defects with an unclear cause
A misaligned door may involve manufacture, transport, foundations or installation. Its appearance alone does not establish fault.
Agree who arranges the inspection, what evidence is needed and how disputed findings are reviewed. Include a process for urgent safety issues while responsibility is being investigated.
The customer's reporting contact
Name a contact for each stage and for after handover. Explain how that contact involves the manufacturer or subcontractor when needed.
The customer should not have to guess which business receives a defect report. This reporting process does not replace legal rights or required notifications.
Keep licensing and insurance separate
Selling a product, carrying out building work and managing a project can involve different obligations. A manufacturer's involvement does not establish that another party is licensed or insured for its proposed role.
Confirm the activities each business will perform with the relevant licensing authority and advisers. Check any building compensation or warranty insurance requirement for the actual contract and project. Do not assume dividing the work removes an insurance obligation.
Use the modular home insurance guide to review construction and transit cover. State building compensation schemes and warranty rights are separate questions.
Documents to agree before work starts
- 01A scope of supply with inclusions, exclusions and the named responsible businesses.
- 02A drawing and variation process with written approval of changes.
- 03An inspection plan covering factory work, site interfaces and installation.
- 04Insurance responsibilities and the transfer of risk between stages.
- 05A defects process with reporting contacts, investigation and escalation steps.
- 06Customer-facing terms that match the agreed commercial and legal scope.
Ask for examples of these documents, then adapt them to the actual project. A sample contract is not confirmation that your site, design or business arrangement is covered.
Questions for a partnership discussion
- Step 01What is included in the supply price, and what remains site work?
- Step 02Who commissions site engineering and coordinates the certifier?
- Step 03Who arranges transport, lifting, access permissions and insurance?
- Step 04Who approves design changes before manufacture?
- Step 05How do we investigate a defect with more than one possible cause?
- Step 06Who is the customer's contact after handover?
If a delivery is damaged, use the transport-damage guide. Agree that response process before the module leaves the factory.
Frequently asked questions
Who is responsible for defects in a modular home built through a builder-manufacturer partnership?
Responsibility depends on the cause, contracts and applicable law. Agree who receives reports, arranges inspections and coordinates repairs. Do not assume that a private factory/site split removes the customer's legal rights.
Who lodges the DA or CDC application for a modular home project?
Assign this task in the project scope. A builder, developer, owner or appointed adviser may manage the application. The manufacturer may supply supporting drawings. Confirm the applicable pathway and applicant requirements for the site.
Does a builder need their own licence and insurance to sell modular homes?
Check the activities being performed, not just the partnership label. Selling, building and installing can have different requirements. Confirm licensing and insurance obligations with the relevant authority, insurer and legal adviser.
Can a builder request custom design changes to a modular product?
Ask the manufacturer to assess the request. Agree feasibility, revised drawings, engineering, approvals, price and timing before accepting a change. Not every modification is available or covered by the original design documents.
Who manages the customer relationship after handover?
Name the reporting contact in the agreement and handover documents. Set out how that business involves other project parties and escalates claims. Keep the customer's applicable legal rights separate from the internal reporting process.
The bottom line
Allocate the work, evidence and reporting contacts before the project starts. Recheck the allocation when the design or scope changes. A clear commercial split supports coordination but does not replace licensing, insurance or legal obligations.
Read about adding modular homes to a House & Land range, or discuss a builder partnership with a defined project brief.
General business information only, not legal, insurance or licensing advice. Roles depend on the actual agreement, work and jurisdiction. Last reviewed: 28 September 2026.
Sources and further reading
Requirements change and can be applied differently by site and local authority. Check the current official sources and confirm your project with the relevant council, certifier or qualified professional.