Remodeling
Attic Remodel Cost Calculator
Prices an attic conversion, where headroom and floor strength decide whether it is possible at all.
Result
A planning estimate, not a quote. Access, the age of the equipment, what is found once it is opened up and local labour rates all move the real figure, sometimes a long way.
Get a Free Business AuditHow the calculation works
Hours times crew times rate, plus materials and the call-out. The work is insulating the roof assembly, building a floor capable of carrying a room, adding a compliant stair, providing egress and running services. Two feasibility tests come before the estimate. Habitable space needs a minimum ceiling height over a minimum proportion of the floor area, which a shallow roof pitch simply may not provide. And the existing ceiling joists were sized to hold a ceiling, not a floor with people and furniture on it, so the floor structure usually has to be reinforced or replaced.
What moves the number
- Roof pitch and available headroom, which determine whether the space can qualify.
- Existing joist size and span, since a ceiling structure is not a floor structure.
- Stair location, which consumes floor area both upstairs and on the level below.
- Egress, which normally means a compliant window or skylight sized for escape.
Where this one goes wrong
Do not assume the attic floor will take a room. Ceiling joists are sized for a ceiling and a modest storage load, and a habitable floor carries a much higher live load, so reinforcing or sisters or new joists are usually needed and that is a structural calculation rather than a judgement. Headroom is the other gate: the requirement is a minimum height over a stated share of the area, so a low pitch roof can fail it however much floor there appears to be. The stair is the cost people forget, because a compliant stair has its own rise, run, headroom and landing requirements and it takes floor space out of the room below as well as the new one.
Before you quote
- Measure headroom against the minimum height over the required area share.
- Get the floor structure assessed before pricing finishes.
- Locate a compliant stair and account for the space it takes downstairs.
- Confirm the egress opening requirement for the new room.
Where the rules come from
Questions
About this calculator
Can any attic be converted?
No. Habitable space needs a minimum ceiling height over a minimum share of the floor area, and a shallow roof pitch may not provide it however large the attic footprint looks. That test, plus the floor structure and a compliant stair, decides feasibility before cost comes into it.
Will the attic floor hold a room?
Usually not as built. Existing ceiling joists were sized to support a ceiling and light storage, and a habitable floor carries a considerably higher live load. Reinforcing with sisters or new joists is normal, and it is a structural calculation rather than something to judge by how solid it feels.
Does an attic room need a special window?
It needs a compliant emergency escape opening in a sleeping room, with minimum dimensions and a maximum sill height. A standard roof window may not meet them. It is a requirement rather than a feature, and it is checked at inspection.
The formula
total = hours x people x rate + parts + call-out, then sales tax
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How to use this calculator
- Hours on site (h). Enter your own figure; the page starts at 160 h.
- People needed. Enter your own figure; the page starts at 1.
- Labour rate charged ($). Enter your own figure; the page starts at $88.
- Parts and materials ($). Enter your own figure; the page starts at $11,000.
- Call-out or diagnostic fee ($). Enter your own figure; the page starts at $95.
- Sales tax (%). Leave at zero if you are quoting before tax.
The result updates as you type, so you can try a figure, see what it does to estimated total, and change it back. Nothing you enter is sent anywhere or saved.
A worked example
These are the figures the calculator opens with. Every number in the results column below is produced by the same calculation the page runs, so you can follow it through before putting your own figures in.
What goes in
| Input | Value |
|---|---|
| Hours on site | 160 h |
| People needed | 1 |
| Labour rate charged | $88 |
| Parts and materials | $11,000 |
| Call-out or diagnostic fee | $95 |
| Sales tax | 0% |
What comes out
| Result | Value |
|---|---|
| Estimated total main result | $25,175 |
| Labour | $14,080 |
| Before tax | $25,175 |
| Sales tax | $0 |
About $25,175: $14,080 of labour, $11,000 of parts and a $95 call-out.
How sensitive the answer is
Holding everything else steady and changing only labour rate charged, this is what happens to estimated total. It is worth knowing which of your inputs the answer actually hinges on, and which barely move it.
| Labour rate charged ($) | Estimated total |
|---|---|
| $44 | $18,135 |
| $66 | $21,655 |
| $88 example above | $25,175 |
| $132 | $32,215 |
| $176 | $39,255 |
Every other input is held at the example value while this one changes, which is not how a real job behaves. Treat it as a guide to which number matters most, not as five separate quotes.
What each figure means
- Hours on site (h)
- Measured in h, between 0 and 400, starting at 160 h.
- People needed
- A number, between 0 and 40, starting at 1.
- Labour rate charged ($)
- A money amount, starting at $88.
- Parts and materials ($)
- A money amount, starting at $11,000.
- Call-out or diagnostic fee ($)
- A money amount, starting at $95.
- Sales tax (%)
- Leave at zero if you are quoting before tax.
What the results tell you
| Result | What it is |
|---|---|
| Estimated total | The headline result. A money figure. |
| Labour | A money figure. |
| Before tax | A money figure. |
| Sales tax | A money figure. |
Estimating is the easy part
The jobs you never hear about cost more than the ones you mis-measure. BDEVY builds the marketing, systems and automation that bring them in.