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The sequential division of the building process is defined in Fasemodellen
(the phase model). The model was introduced to the Danish construction
industry as an element of the industrialisation process during the post-war
period. Basically the model operates with a distribution of work functions
as found in the conventio-nal industry. Each party involved in the process
performs only specialised work based on specialist skills, methods and
tools. Correspondingly all activities in the process are mana-ged tightly
by specialist managers or consultants attached to the project
organisation.
As underlined above this management aspect
is very important, since the organisational set-up for the construction of
any building or plant varies from pro-ject to project. And the
"unique" set-up represents a crucial obstacle to the development
of in-depth collaborative routines as well as long term informal
rela-tionships between the involved parties.
The Danish phase model divides the
construction process into five major parts. In principle, the sequential
build up of specifications during the design phase serves as basis for the
decision making and actual construction. The five phases are:
ù briefing
- proposal (concept and scheme design)
- detail design
- execution (construction)
- operation (facilities management)
These are presented in greater detail in
figure 7.
Briefing
The first step initiating construction is
the identification of the need for a particular project to be constructed.
The spectrum of market segments is manifold: a motorway easing transport
of goods and commuting of people; plant facilities to adapt to new
production technology; housing for the elderly due to demographic
displacements; urban renewal as a measure towards social segmentation; not
to mention the vast number of product varieties within these segments.
In the early stages the basic -ideas in
terms of functionality, aesthetics, and performance are expressed- These
ideas are often formulated in a dialogue between the Bygherre (client) and
the Arkitekt (architect). Depending on the organisational relationship and
the nature of the project also the end-users can be involved even at this
very early stage of the program-ming in order add in their requirements
and experiences.The next task is to summarise the requirements in a
structured man-ner avoiding direct contradiction in terms of feasibility,
economy and legal matters. This also involves the identification of a
potential piece of land on which the construction can take place.
Proposal
Phase (Concept and Scheme Design)
This phase covers an analysis of the actual
possibilities for a constructed product of the specified type on the
available land; a division of the project into sections (or buil-dings).
Alternati-ves in terms of sha-pes/geometry are investigated, and
principles for the load bearing structures and instal-lations are
discussed. Environmental aspects of the project are taken into
consideration and this leads to an overall clarified conception of the
nature of the project.
The project is also interfaced with the
local planning regulations made by regional and municipal authorities. If
the projects deviates from the published plan for the area, the impact of
the project is subjected to a formal hearing offering the inhabitants in
the area the possibility to object against or reject the project
completely. Depending on the strength of the reaction the project is
either altered to suit the previously approved plan or the project is
moved to another area.
The analysis materialises in a feasibility
proposal, in which the- basic layout of the project is determined together
with the key figures on the eco-nomy and the superior time schedule for
the construction project. The proposal ser-ves as a basis for
appropri-ation of the land, and also- as a wor-king basis for the further
stages of the design of the project.
A proposal for the project is then carried
out for the acceptance of the functional, economical and aesthetic
solution. The budget is split into estimates for each section of the
project. This proposal is followed by general conditions for the contract
as well as a description. Finally in this stage a decision is taken on the
method of tender and on the conditions, on which contractors are asked to
tender.
Detailed
Design
The arkitekt og ingeniør (design team) now
works out a preliminary proposal and assures that approvals from relevant
authorities are obtained. The-se approvals form part of the tender
documents. For the actual tendering the designers carry out a final scheme
design. This implies production of the drawings intended for use du-ring
tendering and production.
The detailed design also includes the
tender documents forming the basis on which the tendering invitation is
submitted to the contractors. The tender invitations will normally
comprise:
- conditions for tendering
- tender form
- general conditions of contract
- special conditions of contract
- technical description and specification
- drawings
There is a broad variation in the level of
detailing in the technical description and specification and in the
drawings. This level depends mainly on the contractual model to be chosen
for the project: at one extreme a full specification including a bill of
quantities; at the other extreme a mere statement of the functional
requirements and the economic frame, leaving the rest to the contractor.
The detailed design is followed by the tender. The tender process is
subject to the regulations set in the Licitationsloven (Act on Competitive
Tenders). The scope of this act is to ensure free and open competition for
building and civil engineering works but also to prevent the client from
squeezing the contractors bid in the negotiations following the tender.
The act contains five major conditions:
- bids are invited from two or more
parties
- bidding takes place at the same time and
location
- bids are subject to equal conditions and
information
- bids are in writing and they are binding
- bids are opened and announced in the
presence of the bidders
Tenders can be open (i.e. publicly
announced), or the client can decide to invite contractors for tendering.
The open and public tender is assumed to produce the most competitive bids,
since all interested contractors are bidding. On the other hand the client
might then be lacking experience in relation to the contractors that are
going to build his project. In cases of publicly subsidised building
projects it is obligatory bring it into open, public tender. However some
public building projects are based on a prequalification process of the
bidding contractors. The latter methods can be considered as a hybrid of
an invited tender process maintaining a high level of competition. Design
and build contracts, however, are only partly subject to these conditions
for competitive tenders, since the requirement on equal conditions and
information is not valid when each bidding contractor enters with its own
project.
Larger public building projects and civil
engineering works (value more than 5 million ECU) are subject to
legislation under the European Union. This legislation has a similar scope
as the Licitationsloven ensuring maximum competition between interested
contractors from EU member states. Procedures for the announcement of
invitation for tendering are explicitly described. The EU-directives have
been incorporated in the relevant part of the Danish legislation.
In the invitation for tendering bids can be
drawn up in the following general versions:
- fixed price contracts
- cost plus contracts
Fixed price contracts are either a lump sum
for the works to be done or a unit price followed by a bill of quantities
provided in the specifications for the project. In these cases explicit
procedures are fixed to handle deviations from the original project, such
as variations or fluctuations in the quantities. In the cost plus contract
the price for the work to be done is calculated on the basis of consumed
time, materials and plant.
Fixed price contracts are often used for
reasons of security, since little or no variation from the price is
expected after contract signing. A contract typically includes the
following items:
- contract form (scope of works, the price,
time of completion, payments, guarantee etc.)
- general conditions setting the
relationship between the parties in matters of legal nature
- technical description defining the
execution of the work and stating the make of building parts or
quality of the materials
- the drawings
Execution
In this phase the project materialises. The
organisational arrangement for the actual construction differs from
pro-ject to pro-ject and is based on characteristics like type of client,
technical complexi-ty, aesthetic and functional require-ments.
An important part of this phase is the
supervision of the works. The primary scope of the supervision is to
clarify whether the works carried out are performing to the agreed
standards in the specifications and drawings. The supervision can be split
divided into two parts:
- the client's supervision
- the contractor's supervision
The client has a strong and objective
interest in making sure that the quality is in accordance to the agreement
initially settled with the contractor prior to the commencement of the
execution. The Bygherrerådgiver/byggestyring (construction manager) is
responsible for this by appointing works inspectors responsible for
certain parts of the building or certain operations. The approval of the
works is often connected to the payment to the contractor.
The Entreprenør (contractor) also has a
strong interest in making sure that the operations done are in accordance
with the contract. The cost of correcting works of insufficient quality
often exceeds the value of the works hence giving the contractor a direct
financial objective to make it right the first time doing it. Furthermore
the standard procedures for quality assurance instruct the contractor to
control its own works during construction and to provide documentation of
this control. This documentation is included in the final collection of
documents, which is handed over to the client after completion of the
building.
Facilities
management
The phase during which the building is
being used (consumed) has previously more or less been neglected by the
main actors of the building process. However, in recent years the focus on
the period has increased, partly due to the implementation of the
Kvalitetssikringsreformen, which formally binds all parties to a 5-year
inspection of the building. This also includes elaboration of explicit
plans for the care and maintenance of the building.
Another factor in relation to this shift of
attitude is the recession experienced by the industry in the last decade.
This situation forced many companies to focus on care and maintenance
activities as a potential growing market segment, thus offering clients
systematic services in these fields. To the construction industry a highly
interesting perspective on integration in this phase lies in the obvious
derived total economy considerations, illustrated, for instance, by the
fact that the consumption of cost in the lifetime of a building or a plant
can reach as far as the double or the triple of the initial investment.
Financing
Project financing is obviously a basic task
to be undertaken across all the above mentioned phases. Any building,
plant or infra structural project is considered as being a long term
investment tying up capital for a longer period of time. Again depending
on the type of project and client the financing approach will vary. A
public body will normally operate within annual expenditure limits
(budgets) whilst private companies or persons will try to obtain necessary
financial facilities from either banks or from bond issuing mortgage
banks. For a private client the prospect of return rates on the invested
money will obviously be of great interest. The standard procedure is to
take out mortgage finance based on the value of the project to be
constructed.
Cost
Allocation and Consumption
There is a strong dependence between the
cost allocation/consumption and the different phases of the building
process. This relation -is illustrated in figure 8. The breakdown of the
project in the phase model also gradually reduces the degrees of freedom
of making technological changes to the project. On a project basis the
average, relative distribution of the costs for a typical residential
building is given in table 2 (Erhvervsfremmestyrelsen 1994).
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Briefing