Calculator Inputs
Example Data Table
| Project | Type | Area (m²) | Rooms | Voids | High-Risk Rooms | Samples | Inspection Hours | Site Days | Budget ($) |
|---|---|---|---|---|---|---|---|---|---|
| Office Block A | Management | 1,800 | 28 | 6 | 5 | 28 | 18.60 | 1.43 | 3,740.00 |
| School Annex | Refurbishment | 950 | 22 | 3 | 4 | 20 | 14.20 | 1.09 | 2,640.00 |
| Plant House | Demolition | 2,400 | 16 | 8 | 7 | 39 | 30.80 | 1.58 | 6,230.00 |
Use the sample projects to benchmark building scale, room density, inspection intrusiveness, and budget sensitivity before issuing survey instructions or tender packages.
Formula Used
Base Hours = (Area ÷ 240) + (Rooms × 0.32) + (Voids × 0.55) + (Risers × 0.90) + (Outbuildings × 0.45) + (High-Risk Rooms × 0.50) + (Floors × 0.30)
Inspection Hours = Base Hours × Survey Type Multiplier × Access Multiplier × Occupancy Multiplier × Complexity Multiplier × Destructive Multiplier
Estimated Samples = Ceiling of [((Area ÷ 140) + Room, Void, Riser, Outbuilding, and High-Risk allowances) × Sampling Multiplier × Survey Type Factor]
Site Days = Inspection Hours ÷ (Team Size × 6.5 productive hours per day)
Total Budget = (Labor Cost + Lab Budget) × 1.08
The model combines asset size, room count, intrusive scope, access constraints, and reporting demand to create a defensible early-stage survey brief. The contingency helps cover coordination, permit friction, and minor scope movement.
How to Use This Calculator
- Enter the project name and select the survey type.
- Add gross floor area, floors, rooms, and ancillary spaces.
- Record voids, risers, and high-risk rooms honestly.
- Choose realistic access, occupancy, and complexity conditions.
- Set destructive inspection percentage for the planned works.
- Select the sampling density and reporting detail level.
- Enter lab cost and hourly survey rate.
- Press Calculate Scope to show results above the form.
- Use the CSV or PDF buttons to export the scope summary.
Frequently Asked Questions
1. What does this calculator estimate?
It estimates early survey scope, including inspection hours, sample counts, open-up points, likely team size, site days, and preliminary budget allowances.
2. Does this replace a legal asbestos survey?
No. It supports planning and tender preparation only. Formal surveys must still follow applicable regulations, standards, and competent professional procedures.
3. Why do room count and voids matter so much?
They often drive inspection time more than floor area alone. More distinct spaces and hidden zones usually mean more access checks, materials, and coordination steps.
4. When should I choose a refurbishment survey?
Choose it when planned works disturb building elements. It assumes more intrusive inspection within affected areas than a routine management survey.
5. What does sampling density control?
It adjusts the expected number of samples. Higher density is helpful where material variety, uncertainty, or contractual sensitivity requires stronger evidence.
6. Why include a contingency in the budget?
Contingency covers coordination friction, unexpected access constraints, small scope growth, and administrative effort not obvious during the first estimate.
7. Can I use this for demolition planning?
Yes. Select demolition survey. The calculator increases inspection intensity and sample expectations to reflect more complete access requirements before demolition.
8. How should I interpret the scope band?
It is a planning label only. It helps compare building complexity quickly and supports staffing, programme, and procurement discussions.