Areas measured by R-value and by location, converted to pack counts at the specified batt size, with sarking, thermal breaks and acoustic systems all kept on their own lines.
Insulation looks like the simplest trade to estimate and it catches people out because the same building carries three or four different R-values in different places, each with its own product, its own batt size and its own price.
We measure each area against its specified R-value and convert to pack counts at the actual batt dimensions, so what you get is an order rather than a square metre total. Waste is set by how the batt size fits the framing centres, which is where insulation waste actually comes from.
Ceiling, external wall, internal wall and underfloor areas are measured separately from the plans and the sections, each against the R-value the energy report or specification calls for. Raked ceilings are measured on the slope, and the ceiling area is taken net of penetrations where they are significant.
Areas convert to pack counts at the specified batt width and length, matched to the framing centres. A 600mm batt in a wall framed at 450 centres means cutting every batt, and that is a waste and labour item worth seeing before you order.
Sarking and wall wrap are measured by area with the laps allowed for, thermal breaks by linear metre where the specification requires them, and acoustic insulation is kept separate from thermal because it is a different product against a different requirement.
Nothing here is an allowance. Each line is measured off your drawings in its own unit, so you can check it against the plan yourself.
| Item | How it is measured | Why it matters |
|---|---|---|
| Ceiling insulation | Area by R-value, measured net where penetrations are significant | Usually the highest R-value on the job and the largest single area |
| External wall insulation | Area by R-value, openings deducted at actual size | Deducting openings properly matters most on heavily glazed elevations |
| Internal wall insulation | Area by location — acoustic to bedrooms, wet areas, party walls | Acoustic and thermal are different products against different requirements |
| Underfloor insulation | Area by R-value, with the fixing method noted | Fixing method drives the labour far more than the area does |
| Batt pack counts | Area converted to packs at the specified batt size | Insulation is bought by the pack, so the pack count is the useful number |
| Framing centres | Batt width checked against actual stud and joist centres | A mismatch means cutting every batt — waste and hours |
| Sarking and wall wrap | Area including laps, by product class | Laps are not optional and they are always short if not allowed for |
| Thermal breaks | Linear metres where specified over steel framing | A code requirement over steel and easy to miss on the drawings |
| Acoustic systems | Area by rated system, with the system reference | A rated system specifies the product — it cannot be substituted |
| Location | What sets the R-value | Note |
|---|---|---|
| Ceiling | Energy report and climate zone | Typically the highest R-value on the job |
| External walls | Energy report and wall construction | Cavity depth limits the batt thickness available |
| Internal walls | Acoustic requirement, not thermal | Bedrooms, bathrooms and party walls |
| Underfloor | Energy report, suspended floors only | Fixing method drives the labour |
| Garage / dwelling wall | Fire and acoustic rating | Part of a rated system |
| Raked ceiling | Energy report, measured on the slope | Cavity depth often limits what fits |
Insulation quantities are driven by the energy assessment, not the architectural plan. The report sets the R-value for each element, and those values are what make the building comply, so substituting a lower value is not a saving — it is a compliance failure.
If the energy report is not in the set, we ask for it. Estimating insulation off the floor plan alone means guessing the values, and the guess is usually low.
The same five steps on every job, whether it is a single slab or a full tender package.
Email the architectural and structural drawings, the specification and the scope of works in whatever format you have — PDF, DWG, or photos of a marked-up set. If something is missing we will tell you before we start, not after.
Ceiling, external wall, internal wall and underfloor areas are measured separately from the plans and the sections, each against the R-value the energy report or specification calls for. Raked ceilings are measured on the slope, and the ceiling area is taken net of penetrations where they are significant.
Every measured item gets its own colour and legend entry on the drawing. When the takeoff comes back you can see exactly what was counted and what was not, so you are never asked to trust a number you cannot trace. This is the part clients tell us they did not know they needed until they had it.
The takeoff is delivered as a working spreadsheet, not a locked PDF. Your rates sit in their own column, so you can change a supply price or a labour rate and watch the total move. Plug in your own numbers and the sheet is yours to reuse on the next job.
Quantities are re-measured independently and cross-checked against the drawing before anything leaves here. You get the marked-up plans, the priced spreadsheet and a plain-English note on anything we flagged as unclear or excluded.
The takeoff arrives as a live Excel spreadsheet with the colour-coded marked-up plans beside it. Your rates go in your own column, so you can plug in your own supply and labour numbers and reuse the sheet on the next job. Nothing is locked.
First estimate free. After that the fee is confirmed in writing as a fixed amount before any work starts. No retainer, no subscription, no lock-in contract. Full pricing detail here →
The same house design carries different insulation requirements in Darwin than in Hobart, because the climate zone changes what the energy report demands. That means the batt product and often the batt thickness change too.
We work off the energy report for the actual site rather than a typical value, and where a specified thickness will not physically fit the framing or the cavity we flag it, because that is a design issue better raised at quoting time than at install time.
Quantities are measured against the standards and the specification for your job. Where a drawing and a standard disagree, we flag it rather than quietly picking one.
| Standard | Covers | Relevance |
|---|---|---|
| AS 4859 | Thermal insulation materials for buildings | Material properties and R-value declaration |
| AS 3999 | Thermal insulation of buildings — bulk insulation | Installation requirements |
| NCC Section J / Part 3.12 | Energy efficiency | Required R-values by climate zone |
None of these are unusual. They are the things that get missed when a quote is put together at 9pm after a full day on the tools.
If your question is not here, email it through and you will get a straight answer, not a sales call.
The energy report or thermal assessment, plus the architectural plans and sections. The energy report is the important one — it sets the R-value for each element, and those values drive both the product and the quantity.
If there is no energy report yet, we can measure the areas and leave the R-values as a variable in the spreadsheet for you to fill in later.
Both, with the pack count worked at the specified batt width and length. Since insulation is bought by the pack, that is the number that actually places the order.
Yes, and we flag mismatches. A 600mm batt in framing at 450 centres means cutting every batt, which is a waste allowance and a labour allowance that a square metre figure never shows.
Yes, measured by area with the specified laps allowed for and separated by product class. Roof blanket to metal roofing is measured separately again, as it goes on with the roof rather than with the ceiling batts.
Yes, and we keep it separate as a matter of course. Acoustic insulation answers a different requirement to thermal, often in different locations, and where it forms part of a rated system we list the system reference so the product is not substituted.
Yes, by linear metre wherever the specification requires them over steel framing. It is a code requirement and a linear item, so an area-based estimate will always miss it.
Most residential insulation packages come back within 24 hours of the plans and energy report arriving. Commercial acoustic and rated systems take longer, and we confirm the timing up front.
Most jobs cross more than one trade. We can price the whole package in one spreadsheet.
Your first estimate is free. Email the drawings and the scope, and you will have a marked-up takeoff and a priced spreadsheet back within 24 hours on most residential jobs. Prefer to talk first? Reply with "KEEN" and your number.