Construction

How BPA Cottages Are Built

Your cottage is built in a factory, then transported to your block. Here's what's done before it arrives, and what happens after.

What's Built In vs Site-Specific

Manufactured vs On-Site

ComponentManufactured (Factory)Site-Specific
FrameSteel or timber engineered frame, prefabricated and welded off-siteNone — frame is integral to the cottage
RoofColorbond or Zincalume roofing, insulated, with guttering pre-installedConnection to site stormwater where required
InsulationWalls, floor and ceiling insulated using specifications intended to support compliance with the applicable National Construction Code and relevant Australian Standards, subject to site-specific design, certification, approved documentation and installationNone
Windows & DoorsAluminium or uPVC glazing, fitted and sealed at factoryFinal weather-sealing check on site
PlumbingInternal plumbing roughed-in, bathroom and kitchen fittedConnection to site water, waste and stormwater
ElectricalInternal wiring, switchboard, fittings and fixtures installedConnection to mains power or off-grid system
CladdingExternal cladding pre-installed (optional upgrade)Alternative: on-site cladding installation
Compliance DocsEngineering drawings, structural certs, manufacturer specsSite-specific engineering for foundations and connections
Compliance

Compliance Documentation

Each BPA model is supported by standard structural documentation. Final compliance and approval require site-specific assessment, approved plans, foundations, licensed work and certification.

Included with the cottage

  • Standard structural frame documentation
  • Standard product drawings
  • Available material specifications
  • Available connection details
  • Nominated model documentation

Site-specific and ordinarily additional

  • Soil test
  • Site survey
  • Footing design
  • Wind classification
  • BAL assessment
  • Energy assessment
  • Drainage or wastewater design
  • Planning response
  • Building surveyor fees
  • Amended engineering
  • Site inspections
  • Certification of site works

Site-specific conditions (soil classification, wind region, bushfire attack level, flood overlays) may require additional engineering or modifications at additional cost. Electrical components supplied with the cottage are selected for Australian use and must be connected and certified by a licensed electrician.

Last reviewed: July 2026 · Applicable jurisdiction: Victoria · General information only — not legal, planning or engineering advice.

Requirements vary by property, local government area, building classification and proposed use. Obtain site-specific advice before making financial commitments.