The [Ritchie] Method of an early Negotiated Trade Contractor GMP Contract (NTC GMP C), 2016

Efficiency

The design will benefit from the Trade Contractor’s working closely with the design team from a very early stage of the project. Trade Contractors are also not subject to compromises resulting from a Main Contractor’s profit motives and/or eventual uncertainties resulting from having been appointed to projects with aspects that they are technically unfamiliar with. It should be the case, but rarely if ever is, that the design is only developed ONCE, as a continuum from concept sketches to Trade Contractor’s fabrication drawings, and similarly with specifications. It is an efficient, fully integrated design approach with little or no duplication of effort. The architect produces all the coordinated assembly drawings between Trade Contractors’ packages.

[This is in contrast to the almost complete opposite which happens to the architect and design team – with impact on the Client – under a two-stage D & B contract. The reality in that case is that the architect/engineer produces a complete TRADE CONTRACTOR package, then endures one or more value engineering exercises as the Main Contractor drives up their profit by inflating the design risks during the first stage, resulting in an inflated cost estimate. Then there is an unwelcome demand (usually unpaid) on the architect to re-draw much of what has been done. Then, at the second stage, the Main Contractor undertakes another round of tenders, often using Trade Contractors unfamiliar with the design team and often with less drawing office competence than expected. This can result in a significant number of iterations which nevertheless achieve a less than acceptable build outcome than envisaged. A fuller input is often required from the design team to accommodate changes brought about by an unfamiliar Trade Contractor with a different approach to their package information, e.g. new details which in turn demand interface changes.]

Design Stage

We believe that the detailed design stage can be effectively streamlined by early inputs covering six major construction elements:

1. foundations [including enabling/demolitions]
2. frame
3. main building envelope
4. services – including mechanical, electrical public health, fire/security and IT
5. roofing
6. specialist fit-out

Sometimes the same Trade Contractor can undertake more than one of the above six construction elements. For example: 1. foundations & 2. frame – depending on site conditions or 3. main building envelope might include 5. roofing – if design indicates this: e.g. Leipzig Glass Hall.

Between four and six Trade Contractors will deliver 80-90% of the construction costs, so cost and programme certainty through contracted TRADE CONTRACTOR GMPs is delivered very early.

What level of information is required by the TRADE CONTRACTOR in order to obtain a Contracted GMP?

At this early stage the Design Team delivers scope, quantities and standards, and the key details (notably 3D of interfaces and corners). For example, it is not unreasonable to assume that the structural engineer’s initial concept design and loading specification can be assessed by the specialist and experienced Trade Contractor. This can be costed accordingly and be the cost benchmark for what is included within the Trade Contractor GMP. In the event there is a major change in the initial design intent, these parties can agree a revised cost benchmark. If there is indisputable knowledge of previous good working relationships between the architect/design team with the Trade Contractor then this process can be very quick.

If the Design Team has a QS, and the QS is capable – assisted by the other professionals – in establishing a bona fide construction cost estimate (+/- 5% at time of invitation to negotiate) specifically from elemental costs grouped into trade contract packages costs, it is evident that negotiating with suitable Trade Contractors is far more sensible and efficient and, vitally, creates the opportunity to establish the benchmark quality of the end product. There are subtle techniques involved which do not require expanding here.

The Trade Contractors know their product cost, the cost of assembly and installation and how long it will take to manufacture and build. This information clearly informs the overall budget and programme, and using this method ensures the information is obtained early.