2D & 3D House Design

Introduction

The building design is the process of taking a client's requirements for a new building or changes to an existing building and translating them into an agreed design that a contractor is then able to construct.

Brief

Client's requirements given to the design team may be:

• Expressed in great detail (for example, a retail client requiring another outlet following the same brand as previous stores).
• Described very loosely and then developed in more detail during the design process. An inexperienced client may benefit from input from independent client advisers to prepare a strategic brief, and this may then be developed with the help of a consultant team.
• Expressed in terms of overall functional requirements for the proposed development, that is, what it will enable the client to do, rather than the accommodation it is required to provide. The government recommends that publicly-funded projects adopt this approach.

Typically, the brief for a project will develop alongside the design but will be frozen at the end of the concept design stage and any further changes will then subject to change control procedures.

The stages of brief development may be described as:

• Statement of need.
• Strategic brief.
• Project brief.

Consultants

As the standard of regulations has increased, building components have become more complex, and the technical requirements of clients have become more demanding, so the design process has become more challenging. As a consequence, other than the very smallest projects, building design will generally involve a number of different designers and other consultants.

The designers that are likely to be required on most projects include:

• Architect.
• Services engineer.
• Structural engineer.

However, other consultants, such as a cost consultant are likely to be required, and depending on the nature of the project, specialists such as landscape designer, access consultant, interior designer, acoustic consultant, and so on may also be necessary.

It is becoming more common for a consultant to be appointed on a project, then in turn to appoint other consultants who will undertake some or all of the work for which he/she has been hired. The client's consultants may be referred to as 'prime consultants' whilst the consultants that the latter appoint are generally referred to as 'sub-consultants.

Increasingly, the design also involves contractors or suppliers appointed in the first instance to carry out the design and subsequently to carry out the works on-site or to supply goods or services.

The lead designer will often be the architect, however, this is not necessarily the case and appointment documents for other consultants will generally offer provision for them the be nominated, lead designer. For example, on a very highly serviced building, or part of a building, the services engineer might be an appropriate lead designer. The building surveyor might be appointed as lead designer on a refurbishment or renovation project where their training and expertise in building materials applied to the existing fabric makes them uniquely qualified for the role.

It might also be appropriate to appoint a design coordinator (for the coordination and integration of designs prepared by specialist contractors), and a computer aided design (CAD) and/or building information modelling (BIM) coordinator and a BIM information manager. Contractors may appoint their own design managers to coordinate their own design and that of sub-contractors.

See Consultant team and Design team for more information.

Procurement route

On a traditional project, it is common for the client to appoint an architect first for the earliest stages of development of the project and then to appoint other consultants as it becomes necessary.

However, on design and build projects, the client may appoint a contractor to design the building and then to construct it. The contractor may be appointed from the outset, or the client may first appoint consultants to develop an outline design and then appoint the contractor to take on and develop the design (either using the existing designers or their own).

Other procurement routes offer variations to this basic pattern, with the government favoring the appointment of a single integrated supply team from the outset to design, construct, and sometimes finance and operate the building.

Design development

The design process is an iterative one, passing through a number of stages, during which the client's requirements are clarified, options assessed, designs developed, designs reviewed, progress approved, a decision taken to move to the next stage. Certain aspects of the project are 'frozen' at each stage and change control procedures introduced.

Typically, the stages of design are described as:

• Concept design (outline design or scheme design).
• Detailed design.
• Technical design.
• Production information.

The stages which precede concept design typically involve developing the brief, assessing options, and carrying out feasibility studies. Whilst these stages might include the preparation of diagrams for the purpose of assessment, they do not involve design as such.

Design reviews should be coordinated by the lead designer. Design reviews might include consideration of (amongst other things) design quality, value management, design risk assessment, and project risk assessment. See Design review for more information.

In some circumstances, it may be appropriate to commission design reviews from independent client advisers or from specialist design review organisations (such as Design Council Cabe).

On public sector projects, the government requires that gateway reviews are carried out at key points during the development of the project. See the Gateway review process for more information.