Role of the Principal Designer and Designer

Harry Gardner

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The Principal Designer’s Duties

• If the project uses more than one contractor, the client must appoint a principal designer (PD). They must;

• Plan, manage, monitor and coordinate health and safety in the pre-construction phase of a project. This includes:

• Identifying, eliminating or controlling foreseeable risks;

• Ensuring designers carry out their duties;

• Prepare and provide relevant information to other duty holders;

• Liaise with the Principal Contractor (PC) to help in the planning, management, monitoring and coordination of the construction phase.

• Prepare (or make arrangements with the PC to prepare) the Health and Safety File

Must the Principal Designer remain in place to the end of the project?

It could be considered as desirable that the PD remains consistent throughout the project from concept design to practical completion as the fewer transfers of risk / duties

the better.

However, the designer contracted to develop the concept design and gain planning permissions etc. might not be

best placed or competent to then carry out detailed design and so the PD role may switch from one PD to

another immediately prior to detailed design commencing.

It is acceptable for the PD or even PC to change throughout the duration of the project. However a formal process must be in place to ensure the duties are properly

transferred.

Can a PC also be the Principal Designer?

A single organisation can be appointed as both PC and PD providing they have the competent

resources to fulfil both roles.

The PD role is all about design coordination and control and on a D&B contract this role may therefore be best suited to the PC, who has traditionally carried out this role to ensure

design is delivered in line with the construction phase programme of works.

A PC may welcome the increased ownership but they must satisfy the PD competence

requirements before they can be appointed.

In a D&B Contract can the Appointed Designer be the PD?

There must always be a commercial arrangement between the client and the PD so that he can be

paid for the services rendered.

There may however be an arrangement where the client funds the PD via the contract with the PC

providing the arrangements are made clear ensuring the PD’s costs are ring-fenced etc.

i.e. the contract must be set up in a way that we are not at risk of influencing the designer in a way

that might prevent them fulfilling their CDM duties.

What Information should we expect from the Principal Designer?

You should expect to receive:

Pre-construction information in order to prepare the construction phase plan (this may also be

provided by the client)

Information about the requirements for the health and safety file

Any changes in design that will affect the construction phase

Cooperation in passing on any health and safety- related questions or queries regarding the design

Designers

Designers - are those, who as part of a business, prepare or modify designs for a building, product or

system relating to construction work.

Designers include architects, consulting engineers, quantity surveyors, interior designers, temporary

work engineers, chartered surveyors, technicians or anyone who specifies or alters a design.

They can include others if they carry out design work such as principal contractors, and specialist

contractors e.g. an engineering contractor providing design, procurement and construction management

services.

Designers’ Duties

There is added emphasis on ‘health’ and ‘safety’ risk mitigation at the design phase by applying the general

principles of prevention

Increased coordination across all designers / design teams working towards a single Client H&S Brief / strategy and

clear and effective communication of residual design risks.

One key change that is new to permanent works designers is the inclusion of the requirement to coordinate and

consider temporary works design.

The intended effect of this is again to motivate the permanent works designer to think about the

construction methodology and, in some cases, design temporary works solutions into the permanent works.

Designers’ Duties • When preparing or modifying designs, to eliminate,

reduce or control foreseeable risks that may arise during:

• • construction; and • the maintenance and use of a building once it is

built.

• Provide information to other members of the project team to help them fulfil their duties

• With the new Principal Designer duty holder and with more emphasis on Design Red, Amber & Green lists there is a clear intent for designers to do more in this area.

CDM 2015

BOOTLE BUILDING COLLAPSE 29/01/00

The Project

1 Million Pound project to redevelop derelict properties at 66-74 Stanley Road, Bootle.

To provide low cost housing and commercial outlets

Included demolition of existing properties

“GATEWAY PROJECT”

Funding

Structural Funding - £58,000 European Union

Housing Investment Money – Dept of Environment- £500,000

Match Funding from Sefton MBC

Diary of Events leading up to the commencement of work.

• 30th Sept 1999 Housing Association purchased properties at 66-74 Stanley Road

• 24th Nov 1999 Following selective tendering PC awarded contract on a best price basis

• 7th December 1999 Pre-tender Health and Safety Plan issued by PS

• 9th December PC requested quote from Demolition contractor

Diary of Events leading up to the commencement of work

• 16th December 1999 Health and Safety Plan sent by PC to PS

• 20th December 1999 Client agrees a price of £762k for work

• 21st December 1999 Demolition contractor submits a quote for £24,500 (est. 6weeks)

• 22nd December 1999 PS advises client H+S plan was suitably developed for work to begin

Diary of Events leading up to commencement of work

• 22nd December 1999 PC signs contract with Client. (Keys for property handed over)

• 4th January 2000 Representative of Demolition contractor visits site and prepares method statement.

• 12th January 2000 Demolition contractor and PC gain entry to site.

Diary of Events leading up to commencement of work

• 19th January 2000 Demolition Contractors method statement approved by PC structural engineer.

• 19th January 2000 PC writes to statutory undertakers requesting disconnection of gas and electricity

Diary of Events for Week leading up to Collapse

• Monday: Started work soft stripping (Electricity still connected)

• Tuesday: Gas leak – Site evacuated

• Wednesday: Joists removed from 68 Stanley Rd, scaffold erected. Garage Demolished

• Thursday : Some joists removed from 66 Stanley Road

• Friday : Remainder of joists removed from 66

29th January 2000

At approximately 0930 on Saturday 29th January 2000- The Building at 66-68

Stanley Road Collapsed.

Killing one demolition operative and seriously injuring two other workers

Confusion about how many people were in building at time of collapse Instability of Building (Rescue attempt was suspended until it could be made safe) No Drawings Dreadful weather/ poor light Rescue Dogs located a body nine hours later.

• The Rescue was hampered because:

Imported risk

Stabilising the partially collapsed building

ONSITE INVESTIGATION

Site was taken into HSE Possession+ made secure

(ii) Building made safe by local demolition contractor

(iii) Evidence recovered (Bagged and tagged)

(iv) Every step photographed

(v) Stanley Road closed for four weeks

OFF SITE INVESTIGATION

Paperwork obtained including:

Pre- tender Health and Safety Plan

Health and Safety Plan

Demolition Contractors Method Statement

Site Agents Diary

Local Authority planning department

OFF SITE INVESTIGATION

• Interviewed approx 90 persons

• Obtained 45 statements

• Interviewed ten persons under caution.

Primary Cause of Collapse

• At least 17 out of a total of 21 joists removed from ground floor of No 68

• At least 13 out of 17 from the ground floor of No 66

Primary Causes of Collapse

Upshot of this :

Left the party wall with little or no lateral support !

Cause of Collapse

• The building also had a significant amount of other structural deficiencies as we will see from the model.

Documentary deficiencies

• Inadequate :

Pre-contract Health and Safety Plan

Construction phase Health and Safety Plan

Demolition Method Statement

Summary of issues – Pre start

• Shop fronts – walls built from cast iron beams and lintels

• Floor plans between 66 – 68 different putting a strain on the structural party wall

• Chimney started from floor 1, top heavy construction

• Doors in party wall – weakness

• The roof construction imposed a significant loading on the walls

Summary of Issues – Pre Start

• The building ties, “retro fitted” should have indicated a weakness in the building

• A Tie on the second floor had been cut and a botched anchor arrangement fitted to the internal wall

•No Survey!!!!!

Missed warning !

Previously cut tie to accommodate earlier change of use of the building

Factors contributing to the collapse

• Floor boards removed • 30 - 38 floor joists removed at

ground level • Removal of floor joists on upper

floor at the front of the building • Non load bearing internal walls

removed.

Factors contributing to the collapse

• Windows and doors removed

increasing wind loading on the

building weakened by the above

actions

• Steel beam left from the garage

demolition bent back by the

machine to allow access for the

skip, stress on building

Estimated total Cost of the Building Collapse

Somewhere in the region of :

SEVEN MILLION POUNDS