Design and Build - is this an
option for residential development?
Design and Build projects are usually developer or builder lead. This is
where they work out what they can supply for the money which is often just the basic structure with all
the fit out as an optional extra cost item.
This can be an attractive method of procuring a building for a client but this method does
not usually allow a great deal of client induced features or bespoke element of design that is so often the
important element when extending an existing property.
Design and build projects usually favour system build schemes for stand alone
structures rather than complicated adaptation works to existing structures.
However, there are builders out there who do specialise in this form of domestic extension
work and they usually employ their own 'plan drawer' simply to do the minimum work to secure Planning and Building
Regulations approvals. They will then provide their own extra fit out schedule or outline schedule of works
for what they will be providing for the fixed sum of money.
If your project is a simple 'bolt on' type of extension (conservatory, extending one room
etc.) then you may not require the services of an Architect or Technician to help you with your scheme.
However, it has been my experience that this is not the norm and some form of remodelling is
normally required with good design advice being the backbone of securing a well designed, good looking, well
planned structure. This is where your independent experienced residential Architect or Technologist
can help with their added value is design matter that they can bring to the table.
CHP does not get involved with Design and Build projects.
The popularity of “design and build” for major projects seems to have declined somewhat since
its heyday in the 1980’s. This method of procurement originated back in the 1950’s when it was promoted by
contractors as an alternative to the traditional method where the professional team and the contractor were
employed individually and separately by the client. Instead, the design and build contractor would provide a
package to include all necessary professional services.
In the 1980’s an important contract-writing body known as the Joint Contracts Tribunal,
produced a form of contract called the “JCT 1981 With Contractor’s Design” and this heralded an expansion of the
design and build package being offered.
There can be advantages to having all the responsibilities for detailed design and
construction in one place, not least because the contractor can programme the supply of information and details
from his designers, reducing team conflict. The pre-contract process may be shortened with this method of
Several high-profile cases have been reported where projects employing design and build
contractors have turned out to be a disappointment. Care and preparation are needed to make sure this does not
happen. It is likely to be necessary to have a design produced in outline or in some detail and then apply various
performance criteria and a specification, so the contractor has a strict definition of what he is meant to bid for
and how he must subsequently construct the building.
There are many specialist firms offering design and build packages for small works such as
loft conversions or swimming pools and they can often be very successful and cost-effective in their specialist
fields. When it comes to larger projects, great care is needed in defining the design and build package that is
Considerable skill is needed in setting up a design and build contract.
1. Design and build requires a high level of client input in order to
cover all the issues to be included that would normally be completed by the Building
Designer acting for the client.
2. A separate client advisor is still likely to be