Infestation Risk Score Calculator

Formula used

Each factor gets a level from 0 to 10 and a weight in percent. The final score is a weighted sum scaled to 0–100:

• Weights should total 100% for direct interpretation.
• Contribution per factor equals Weight × Level / 10.
• Risk bands: Low (<25), Moderate (25–49), High (50–74), Critical (≥75).

How to use this calculator

1. Walk the site and choose the closest option for each factor.
2. Keep default weights, or enable custom weights for your region.
3. Press Calculate risk score to generate results.
4. Review top drivers and apply the recommended actions.
5. Download CSV or PDF to share with your team.

Risk scoring in construction environments

Construction sites create temporary openings, wet trades, and material stockpiles that raise pest pressure. This calculator converts field observations into a 0–100 score so teams can prioritize fixes. A 10-point change typically reflects one major control improved, such as sealing access routes, removing food sources, or drying persistent damp zones before cladding closes.

Moisture and drainage as primary drivers

Moisture is weighted heavily because damp timber, insulation, and subfloors support termites, ants, and mold-associated insects. Ponding near foundations increases entry attempts and hides activity. Target outcomes are dry surfaces, no standing water after 24 hours, and downspouts discharging away from the slab line. If the moisture level is 7/10, reducing it to 3/10 can cut the total score by roughly 7.2 points at an 18% weight.

Openings, penetrations, and work sequencing

Gaps around ducts, doors, and service penetrations act as direct pathways. During fit-out, the number of penetrations can double, so the same building may score higher mid-project than at handover. Sealants, screens, and door sweeps provide rapid reduction. Track the “gaps” level weekly when multiple trades are active and document photos to justify corrective orders.

Material susceptibility and storage controls

Untreated wood, cardboard, and clutter create harborage and food sources. Stacking timber off the ground by at least 150 mm and keeping a 2 m inspection zone improves detection and reduces contact risk. Waste removal frequency is a controllable lever; moving from weekly to daily skips can lower the storage factor by several points. Pair this with a “no wood-to-soil contact” rule to prevent hidden bridging.

Using outputs to plan inspections and budgets

Use the band and the top drivers to build a corrective list with owners and dates. For Moderate scores, schedule monthly walkthroughs until stable. For High and Critical scores, budget for moisture remediation, sealing packages, and professional inspection. If you customize weights, keep the total at 100% or enable auto-normalize so results remain comparable across projects and audit periods on time.

FAQs

1) What does the 0–100 score represent?

It is a weighted summary of site conditions. Each factor level (0–10) is multiplied by its weight and scaled, then contributions are summed. Higher scores indicate higher likelihood of infestation pressure and entry opportunities.

2) Can I change the weights for my region?

Yes. Enable custom weights and enter percentages that reflect local climate, materials, and known pests. Keep the total at 100% for direct comparison, or enable auto-normalize to rescale automatically.

3) How often should the site be re-scored?

Re-score after major trade phases, heavy rain events, or corrective works. For Moderate risk, monthly is practical. For High or Critical risk, review every 2–4 weeks until moisture and openings are controlled.

4) Which factors usually drive scores the most?

Moisture, wood-to-soil contact, and unsealed openings commonly dominate because they enable activity and access. The results table lists the top three contributors so you can target actions that reduce the score fastest.

5) Is this a substitute for a professional inspection?

No. It supports planning, documentation, and prioritization. If you observe active signs, structural damage, or repeated reinfestation, engage qualified inspectors and follow local regulations and safety procedures.

6) What do the exports include?

CSV and PDF exports capture project details, the overall score, the risk band, and a factor-by-factor breakdown with weights and contributions. Use them for handover files, contractor coordination, and audit trails.

Example data table