Bulk insulation (batts, rolls and blown-in) is where most of your new home's comfort comes from. Here's what types are used in Queensland homes, what R-values you need, and how to check it's installed properly before the plasterboard hides it forever.
C10 - Rough In Stage Inspection Checklist
$59.00 AUD
Last updated 5 Oct 2026 · Revision 1 · Free updates for life
Checklist Type: Minor
Form Factor: Fillable, print-ready PDF (A4, 25 pages)
When to use: Rough-in stage: after services are installed, before cladding and linings go on
A 200-point rough-in checklist. Check electrical, plumbing, gas, solar, membranes and air-conditioning ducts before cladding and linings hide them, while changes are still easy.
What is bulk insulation?
Bulk insulation traps air to resist heat flow. It includes batts, rolls, boards and loose-fill (blown-in) products made from glasswool, polyester, rockwool or cellulose. Reflective foil is the other main type. Foil works by reflecting radiant heat, and in Queensland it's common to see both: a foil blanket or sarking under the roof and bulk batts in the ceiling and walls.
Every product has an R-value, which measures how well it resists heat flow. The higher the R-value, the better it insulates. Two batts of the same thickness can have different R-values, so always go by the R-value printed on the label, not the thickness.
Types of bulk insulation
Glasswool
The most common choice in Australian homes. Made from fine glass fibres, often with recycled glass content. Available as batts and rolls for ceilings, walls and floors, and as loose-fill. It's affordable, non-combustible and helps with sound. It can irritate skin and lungs during handling, so installers should wear gloves, long sleeves and a mask.
Rockwool (stone wool)
Made from spun volcanic rock. It's denser than glasswool, holds its shape well, resists moisture and is non-combustible, which makes it useful in bushfire-prone areas and where fire or acoustic performance matters. It usually costs more than glasswool.
Polyester
Made from polyester fibres, often recycled plastic bottles. Soft and itch-free to handle, so it's popular with DIYers and for people with sensitivities. Generally more expensive than glasswool for the same R-value.
Cellulose (loose-fill)
Made from recycled paper treated for fire and pests, and blown into ceiling spaces. It fills around obstructions well, but it can settle over time, which lowers its R-value.
There's a practical problem with loose-fill that I've seen many times on site. As ceiling joists and truss bottom chords dry out and shrink, a small gap opens between the plasterboard and the timber. The light, loose insulation migrates into that gap. You only find out when you try to fix popped nails: the sheet won't pull back up to the timber because insulation is jammed between them. For new homes, I prefer batts.
What R-values does your new home need?
Under NCC 2022, most new homes need a 7-star NatHERS energy rating, or must meet the code's elemental (deemed-to-satisfy) provisions. Your energy assessor's report sets the R-values for your ceiling, walls and sometimes floors, along with things like glazing and roof colour.
Get a copy of the energy rating report and the stamped plans, and check the insulation that arrives on site matches. If the report says R3.5 ceiling batts and R2.0 wall batts, that's what should be installed. Substituting a lower R-value to save money can mean your home no longer complies.
How to check the installation
Insulation is one of the most common items to get rushed, and once the plasterboard is up you'll never see it again. Check the walls at the end of rough-in, before plasterboard, and check the ceiling as early as you safely can.
What to look for:
- Correct R-value. Check the labels on the packs or batts match the energy report.
- No gaps. Batts should fit snugly between studs and joists, edge to edge. Small gaps cut performance more than you'd expect.
- Not compressed. Squashed batts lose R-value. Batts shouldn't be crammed behind pipes, cables or noggings, or pushed tight against sarking.
- Full coverage. Check around windows, behind baths and in corners, which are easy to miss.
- Clearance around downlights and fans. Unless the downlight is rated to be covered (IC-rated), insulation must be kept clear by the distance the manufacturer specifies. Too close is a fire risk.
- Clear of heat sources. Keep insulation away from flues, exhaust fans, transformers and other heat sources as required by the product instructions.
- Wall wrap and sarking intact. Tears should be taped before cladding or roofing covers them.
Take photos of every wall and the ceiling before the plasterboard goes on. They're your record if comfort or compliance is ever questioned.
Our C10 Rough In and C11 Enclosed stage checklists include these insulation checks.
Safety in the ceiling space
Working in a ceiling space carries real risk of electrocution and heat stress. Turn off power at the switchboard, never staple near cables, and use a licensed installer. Ceiling spaces in Queensland can easily exceed 50°C on a summer day.
This isn't theoretical. During the federal Home Insulation Program in 2009 and 2010, four young installers died, three of them electrocuted in Queensland ceilings. If you're adding insulation to an existing home, use an experienced installer who isolates the power and checks the wiring first.
The benefits
- Comfort. Fewer hot and cold spots, and rooms that hold their temperature longer. In a Queensland summer, good ceiling insulation is the difference between a bearable bedroom and an oven.
- Lower running costs. Your air conditioner doesn't have to work as hard, which saves money every year.
- Less noise. Bulk insulation in walls and ceilings reduces noise from outside and between rooms.
- Less condensation. Insulation keeps rooms more comfortable and reduces condensation on ceilings in winter.
- Smaller footprint. Less energy used for heating and cooling over the life of the home.
What about cost?
Prices vary a lot with product, R-value, area and access, so get quotes rather than relying on a per-square-metre figure from the internet. On a new build, insulation is part of your contract price. The thing to check isn't the price, it's that the R-values in your contract and energy report are what actually goes in.
The bottom line
Insulation is one of the cheapest parts of your home to get right and one of the hardest to fix later. Know your R-values, check the install before the plasterboard goes on, and take photos. Your future self, sitting in a cool bedroom in February, will thank you.
