Short answer
If you are bidding on a former yard, a garage plot, an infill site behind a workshop, or an agricultural building conversion, contamination risk is one of the fastest ways to lose money. A Phase 2 intrusive ground investigation can cost £8,000 to £20,000 and take 4 to 8 weeks, and many LPAs will not validate applications on previously developed land where contamination risk is plausible without Phase 1 evidence. A 48-hour desktop Phase 1 tells you whether Phase 2 is likely to be triggered before you exchange, before auction, or before your bid deadline.
A Phase 1 desk study (also called a preliminary risk assessment) is the first stage of contaminated land assessment for an English planning application. It establishes whether a credible source-pathway-receptor pollutant linkage exists, by reviewing historic Ordnance Survey maps, regulatory records, mining and landfill databases, BGS geology, radon mapping, and prior planning history.
PF & Co produces the desktop Phase 1 layer within Site Appraisal (£199 to £399) for go/no-go decisions, and within the Pre-Application Pack (from £1,995) where it sits alongside FRA, Heritage, Transport, BNG, and other constraint-triggered desktop reports. Typical turnaround is 48 hours from confirmed boundary and brief, subject to data access and scope confirmation. The position in Wales, Scotland, and Northern Ireland differs from the England-focused workflow described here.
Order a Site Appraisal or See a sample report.
When a Phase 1 desk study is triggered
In our experience, a Phase 1 is triggered by any one of the following:
- Brownfield site with any prior built use, including small infill behind a workshop, yard, or garage
- Garage-to-housing, pub-to-residential, or agricultural building conversion (1 to 20 homes is the common small-developer pattern)
- Site identified on the LPA's contaminated land register under Part 2A of the Environmental Protection Act 1990
- Historic industrial, commercial, transport, or agricultural use on or adjacent to the site
- Proximity to historic landfill, gasworks, fuel storage, dry cleaners, vehicle workshops, or scrap yards
- Proximity to a Coal Authority Development High Risk Area (a separate Coal Mining Risk Assessment workstream applies, see Coal Authority guidance on coal mining risk assessments)
- Site within a radon affected area per the UK Radon Map
- Sites with made ground or imported fill
- LPA Local List validation requirements that explicitly require a Phase 1
Many LPAs may require a Phase 1 where contamination risk is plausible, applying the planning policy expectation that development is safe for its proposed use. We check the LPA local list and site history before you spend on a full consultant Phase 1.
The simple buyer questions are: will the council ask for this, will it delay validation, and will it trigger boreholes. The desktop screen answers all three. Where Phase 2 is in turn triggered, we name the indicative cost range (£8,000 to £20,000 typical) and typical 4 to 8 week timeline. See the development land due diligence guide for the wider acquisition workflow.
What our desktop Phase 1 covers
| In our desktop Phase 1 | Sourced from |
|---|---|
| Historic land use review (1880s onwards) | Historic Ordnance Survey maps |
| Regulatory records (Part 2A register, EA permits, EPA notices) | LPA register, Environment Agency public register |
| Landfill and waste site proximity | EA historic landfill database |
| Mining legacy (coal, non-coal, brine, gypsum) | Coal Authority and BGS mining records |
| Radon affected area screening | UK Radon Atlas (UKHSA / BGS) |
| BGS geology and made ground | BGS GeoIndex bedrock and superficial |
| Pollution incidents proximity | EA pollution incidents register |
| Asbestos likelihood from historic building age and use | Land use age and sector profile |
| Source-pathway-receptor screen | Combined dataset analysis with site-specific receptor identification |
| Phase 2 trigger flag | Combined judgment per GOV.UK Land Contamination Risk Management framework |
The desktop Phase 1 is a planning-grade screen of whether Phase 2 intrusive ground investigation is likely to be needed. Where Phase 2 is flagged, the report names the indicative scope (typically rotary bore, trial pits, and a laboratory schedule for relevant contaminants), indicative cost range, and typical timeline.
What this desktop Phase 1 does not replace
Not in the desktop layer:
- Phase 2 intrusive ground investigation (boreholes, trial pits, BRE 365 infiltration testing, lab schedule)
- Soil, groundwater, ground gas, and vapour sampling and monitoring
- CL:AIRE Definition of Waste Code of Practice site-specific assessment
- Remediation strategy and method statement
- Ground gas risk assessment to BS 8485:2015 + A1:2019
- Chartered geo-environmental engineer's signed Phase 1 report under their PI, where a lender or vendor requires formal reliance
- Foundation engineering recommendations and site-won material reuse strategy
Where any of these are triggered, the report names the specialist study, indicative cost range, and typical timeline. See what is included in our 48-hour desktop pack.
Four packs sized to four decisions
| Pack | What it does for ground conditions | Best for / reliance level | Price |
|---|---|---|---|
| Site Appraisal | Identifies historic land use, contamination indicators, mining legacy, and Phase 2 trigger | Bid or pre-screening, internal decision use only | From £199, 48 hours |
| Feasibility Intelligence | Adds abnormal cost provision for Phase 2 and remediation | Pre-acquisition or pre-architect, internal viability use | From £895, 48 hours |
| Pre-Application Pack | Adds desk-based Phase 1 evidence to support pre-application discussion | Pre-app meeting booked. Where the LPA or a lender requires a signed consultant Phase 1 under PI, that remains a separate commission | From £1,995, 48 hours |
| Planning Intelligence Pack | Coordinates desktop outputs with a chartered consultant Phase 1 (and Phase 2 / remediation strategy where commissioned) | Application submission requiring formal reliance | Tailored, timeline subject to specialist scope |
Market pricing for a consultant Phase 1 varies by site, region, scope, reliance, and urgency. Our desktop layer compresses the screening element to 48 hours and integrates it with the wider constraint set. For the full submission picture, see the guide on what reports you need for planning permission.
Send the boundary today
Three steps:
- Send postcode, red-line boundary, intended use, and indicative dwelling count.
- Receive the constraint screen with Phase 1 trigger, contamination indicators, and Phase 2 cost provision in 48 hours.
- Decide whether to bid, walk away, commission a formal consultant Phase 1, or move straight to Phase 2.
£199 to walk away from a heavily contaminated site. £895 to put the abnormal cost into the bid model. £1,995 to walk into pre-app with the desk-based Phase 1 evidence ready.