Pre-Acquistion Studies
Purchasing a development site, without fully understanding the engineering constraints can turn out to be a very expensive mistake, and will lead to a unsuccessful development in terms of profitability.
Paul Waite Associates can provide pre acquisition information that gives you the knowledge to negotiate with the land owner from an informed position in order to maximise a profitable outcome by fully allowing for the unforeseen.
The pre acquisition study would consist of the following items; however it can be tailored to your specific requirements.
Topographical Survey
Paul Waite Associates work closely with a number of land surveyors and we will manage the topographical survey requirement on your behalf.
The topographical survey will enable the site boundaries to be understood so that the full extents of the site can be worked to.
The topographical survey will also highlight the location of surrounding buildings including ridge heights. This will ensure stand-off distances are adhered to when laying out the site.
The survey will be to ordnance survey benchmark standards which is required for tying the site to flood risk issues and drainage levels as the project develops.
Highway Access
Paul Waite Associates experience in liaison and negotiation with highway authorities will enable us to advise on highway access locations including visibility splays. By defining the visibility splay will also assist with determining whether 3rd party land is required to enable the visibility splays to be constructed.
Site Investigation
Not doing this will cost you in the long run.
What looks like a clean site may not be and sites with existing structures present does not always mean simple foundations.
Paul Waite Associates undertake a phased approach to undertaking ground investigations.
Phase 1 – Desk Top Investigation
The Desk Study or Phase I is the first step in the process of geo environmental site investigation of a site prior to development.
It is the probably the most important stage of the investigation process allowing the you to see the way the project is likely to progress. It can highlight potential cost savings as well as potential problems and can delineate the whole process of investigation, remediation and development of a site allowing you to assess the potential cost and/or savings on a stage by stage basis.
The desk study pulls together all the available information on a site prior to any intrusive investigations and allows the construction of an initial Conceptual Site Model which identifies potential risk such as contaminated land or abnormal foundation costs. The Desk Study can be used in the first part of the Regulatory Approval such as the Local Authority (LA) or Environment Agency (EA), process where it can fulfil a planning condition that requires discharging.
Paul Waite Associates can provide comprehensive and cost effective geo environmental Phase I – Desk Study report services in line with CLR7 and CLEA Guidelines within your required timescales.
Phase 2 Intrusive Investigation
The Site Investigation or Phase II is the intrusive part of the investigation and may include any or all of the following:
• trial pits: hand or machine excavated, usually with a JCB, to assess the macro-fabric of the shallow ground conditions in soils and to provide samples for contamination and geotechnical testing.
• mini rig boreholes: a small machine that can fit through a standard doorway used to assess the shallow ground conditions in soils and to provide samples for contamination and geotechnical testing
• cable percussive boreholes: a large tripod machine used to assess the shallow and deep ground conditions in soils and to provide samples for contamination and geotechnical testing
• rotary boreholes: generally a lorry or trailer mounted rig used to assess the subsurface ground conditions in rock. Can be open hole which does not produce samples and is mainly used to check for shallow mine workings; or cored which produces a “core” or rock that can be logged and strength tested.
• Gas and water monitoring wells: Points within the groundmass to continuously test for the groundwater level and/or gases such as methane, carbon dioxide and oxygen. The pipes are generally between 19mm and 50mm in diameter.
• geophysical surveys: Such as magnetrometer surveys or infra red aerial photography to locate mineshafts, ground penetrating radar for non invasive study of changes of ground conditions
• in situ testing such as hand vanes in trial pits and Standard Penetration Tests and cone penetration testing in boreholes to assess soil strength, pH, immuno-assay for limited on site contamination assessment
• contamination and geotechnical laboratory testing: the standard PWA Soil suite tests for a range of common contaminants including metals and organics. Geotechnical testing includes soil and rock testing, plasticity of cohesive soils for heave potential and compressibility testing.
• Reporting: PWA can provide robust accessible reports that are suitable for submission to regulatory bodies such as the Local Authority (LA) or Environment Agency (EA).
The ground investigation is based on the findings of the desk study and the requirements of the development of your site. The Conceptual Site Model is refined, the risks are positively defined and the initial remedial measures outlined. If the site contains unacceptable risks from contaminants they may require removal or encapsulation. The site investigation can identify levels, hazards and materials on site using Soil Guideline Values (SGVs) or Generic Assessment Criteria (GACs).
PWA can save you money by undertaking targeted, cost effective site investigations transparently priced on an Bill of Quantities re-measure basis.
Paul Waite Associates Geo Environmental team have over 15 years experience of planning, supervising and report site investigations to BS5930, BS1377, BS10175, Eurocode 7 & CLEA.
Flood Risk Assessment
The changing weather patterns over the next few decades will mean wetter periods and so increasing the likelihood of flooding.
Flood Risk Assessments have become a requirement for planning applications for all major development and developments in areas that are at risk from flooding.
Paul Waite Associates apply a risk based approach to flood assessment in accordance with Planning Policy Statement 25 (PP25).
In the process of preparing a flood risk assessment Paul Waite Associates provide our clients a solution to the storm water drainage discharge so as to consider the development as a whole. Paul Waite Associates recognizes our clients duties of protecting downstream systems so that existing drainage is not over whelmed and flooding is caused.
Paul Waite Associates will consider as part of the assessment the following:
• Identify flooding levels from consultation with regulators
• Increased run-off from development and its consequences on down stream systems
• Site levels and impact from flood levels
The preliminary information will identify flood risk. The next stage is to understand the mechanics that cause the flooding and how these can be managed to provide on acceptable development in accordance with PPS25.
Paul Waite Associates undertakes HEC-RAS modelling to understand these mechanics in order to design flood mitigation works so that the development is protected and no increase in flooding downstream or upstream is experienced.
England, Scotland and Wales employs different technical guidance on providing flood risk assessment.
England (PPS25)
Planning Policy Statement 25 Development and Flood Risk (December 2006)
Click here to download
Scotland (SPP7)
Scottish Policy 7 Planning and Flooding (February 2004)
Click here to download 
Wales (Tan 15)
Technical Advice Net13 Planning and Flooding (February 2004)
Click here to download
Contamination and Development Proposals
Planners, Building Control, NHBC and the EA are all hot on seeing how you, the developer will deal with contamination issues. Taking it away from site is prohibitively expensive and onsite treatment may not be an option.
The solution is to value engineer the site, such as
1. Risk the problem away
2. Look for areas where it can be capped or buried and capped
3. Use the contaminated material in an earthwork solution….landscape bund
Providing that you have a contamination report (Phase 2 Intrusive Investigate), then this is an opportunity to make great savings by choosing the correct remedial solution.
Paul Waite Associates design the Phase 2 intrusive investigation in order to provide the correct information so that development proposals can be formulated around the site constraints.
Earthwork Proposals
Projects can be won or lost by how you treat earthworks. Take it away from site and you throw away your profits. Yet, with a robust Site Investigation and measured site survey, the right software can carry out a cut and fill exercise. This exercise will balance the earthworks to minimize what is taken off site and just as important, what is now not required on site.
It is therefore imperative to carry out a cut and fill balance exercise
Other Benefits
By following these steps, not only could you make great cost savings, but you will also have the following additional advantages.
1. Provide a proposed site with due diligence. This would enable the banks to finance a scheme, the risks are fully understood
2. It also provides land owners with an information pack to sell land with un-conditional bids
3. The information produced will also support the planning application under the “One Application Process” that is now employed across the country
For further information click here to contact us or call 01535 633350 or 0113 2372929
Click here to return to top of page or to Civil Engineering home page
