Floor plans and elevations don't show how your home is built. Before you sign, ask for the construction details that do.
Some builders cut corners under time and cost pressure. Construction details, the drawings and specifications that show how each part goes together, are how you check what you're actually getting. Your contract plans and specification also set the standard the builder is held to. If something isn't written down, it's hard to argue about later.
C4 - Asking the Right Questions Checklist
$39.00 AUD
Last updated 28 Oct 2026 · Revision 3 · Free updates for life
Checklist Type: Minor
Form Factor: Fillable, print-ready PDF (A4, 26 pages)
When to use: Choosing a builder (before you pay a deposit or sign)
70 questions and checks for every builder on your shortlist, from the licence search at your desk to a visit to one of their current sites. Compare like for like and choose your builder with confidence before you pay a deposit.
What to ask for before you sign
Structural documents
- Soil test (geotechnical report) and site classification
- Engineer's slab and footing design, including reinforcement and concrete strength
- Wind classification for your site
- Frame details: timber or steel sizes, tie-downs and bracing, or the frame and truss supplier's design
- Structural steel beams and columns, staircases, balconies and decks
These carry the weight of your home and resist the wind, so they must be designed by an engineer for your site, not copied from the last job.
Specification
- Windows and doors: brand, frame type, glazing and energy ratings
- Roofing, cladding and insulation (with R-values)
- Kitchen and bathroom fittings, benchtops, cabinetry and flooring
- Air conditioning, hot water and major appliances
Check every item against what you were shown in the display home. If the spec just says "standard", ask what standard means: brand, model and range.
Electrical, plumbing and services
Ask for the electrical plan (power points, switches, lights, data and the switchboard location) and the hydraulic plan (water, sewer and stormwater). You can't assess wire sizes or pipe falls from a drawing, and you don't need to. Wiring must comply with AS/NZS 3000 and is installed and certified by licensed electricians, with RCDs (safety switches) protecting the circuits. Plumbing is installed by licensed plumbers and inspected under Queensland's plumbing approvals. Your job is to check the layout suits how you'll live in the house.
Waterproofing
Water getting in is one of the most common defects in new homes. Ask for these details specifically:
- Waterstop at the doorway into each bathroom, ensuite and laundry
- Shower set-down (hobless) or hob detail
- Bath hob and bath waterproofing
- How pipe and fitting penetrations are sealed
- Balcony and deck waterproofing, if you have them
Roofs, flashings and box gutters
- Flashing at the head and sill of windows and doors
- Roof junctions and wall-to-roof flashings
- Box gutter size, fall and overflow (box gutters must have an overflow)
- Sarking or roof insulation under the roof covering
Our C13A Waterproofing Design, C8 Metal Roof and C9 Tile Roof checklists on the Checklists page go through these details point by point.
Approvals and insurance
Get copies of the building approval and the QBCC Home Warranty Insurance certificate before work starts. Don't let a builder start without them.
Review the plans before you sign
Go through the plans with a fine-tooth comb. Are materials, fixtures and structural elements clearly specified? If anything is missing or unclear, ask the builder in writing and get the answer in writing. If you're not confident, pay an independent building consultant or engineer to review the plans. It's money well spent.
It's much easier to change things before construction starts. You have the most leverage before you sign, so ask for amended plans that address your concerns. A builder who drags their feet over reasonable requests at this stage is showing you how the rest of the job will go.
Why it matters
- Workmanship: clear details tell trades what to build. Vague plans leave room for mistakes and shortcuts.
- Cost: if it isn't detailed and priced, it can come back as a variation.
- Proving defects later: without plans, specs and photos, it's hard to prove what should have been built. Defects you can't prove are defects you pay for.
- Resale: buyers and their inspectors like to see approved plans and certificates.
Checking the work matches the plans
Good details on paper don't guarantee good work on site. The details have to reach the trades, the trades have to follow them, and a supervisor has to check.
- Visit the site regularly. Compare what's built with the drawings. Take dated photos and notes of anything that doesn't match.
- Get independent inspections at key stages, especially the slab and frame. A good foundation and frame go a long way.
- Raise issues early and in writing with your supervisor, so they're fixed before they're covered up.
If you think a stage isn't complete or has defects, raise it in writing under your contract's dispute process before the payment is due, and get advice from the QBCC or a building lawyer before withholding anything. Withholding a progress payment without following the contract can put you in breach.
As-built drawings
Most project-home contracts don't include as-built drawings. Ask before you sign whether as-built or marked-up plans are included, and get it written into the contract if they matter to you. Either way, keep every plan, specification, variation, certificate and photo from your build. You'll need them if something goes wrong.
The bottom line
Don't assume your builder will get every detail right. Ask for the details, read them, ask questions, and push back before you sign. Then check the work against them as it goes up. That's how you end up with the home you paid for.
