The first stage of developing route options should start with procuring the latest OS map of a study area. The OS Map tile allows for the early design and dimensioning of route options to later be developed using a format appropriate for development into detailed design.
It is useful to note at this stage of project development, the difference between main spine length (large diameter bulk export pipe) and branch lengths (smaller diameter pipe, which typically serves a single development/consumer), as they impact both costs and available technical solutions. Additionally, initial expansion and consent strategies can also be introduced/annotated at this stage. However it should be noted that without a detailed appraisal of the buried environment these designs are concept only.
Whilst informative, all too often this level of initial concept design, actually represents the final level of risk management/design development where many Heat Network project designs go to “all risk” construction tenders.
The main reason for this practice is a lack of commercial awareness regarding the impact this approach has on costs/risks; together with insufficient project guidance regarding the substantial civil and coordination risks/costs associated with undertaking major/complex projects within dense city centre environments, All too often, commencing a civil project with insufficient route proving results in excessive additional costs for the client during tender and construction, as the Contractor is provided with insufficient information to appraise their risks against, and routes materially change in construction.
As a result, typical industry costs are rising, and can often deem feasible schemes, commercially unviable because of factoring in “all risk” rates, instead of reducing risks through detailed designs. Additionally, the difference between contract cost and end cost to the client is rising as an alarming rate, and this is predominantly due to a lack of de-risking of the buried environment and early route proving/development.
Very few industries enter into construction contracts with such an inadequate level of design/information, and the following stages in this guide therefore aim to set out more appropriate measures which can be used to significantly improve the accuracy of the design and pre-construction process.