As in the concept and preliminary design stage, the level of your involvement is impacted by the procurement option you have selected. The table below highlights the main differences.
Your involvement is minimal as you are buying a package that includes a standard design.
Design & Build
Your involvement depends on the degree of customisation you require, and what is agreed with the builder.
As the name suggests, design is entirely tailored to fulfil your needs, therefore you will be heavily involved in detailed design. You need to work closely with the designers to achieve optimum results.
Communicate with the design team
As the project develops, the design team’s job becomes more technical and their documents and drawings harder to understand for someone without the background experience. You may feel daunted by this but it is crucial to keep up with developments and maintain communication with the designer. You have the right to express your doubts, but do this in clear and timely manner so that you are giving designers constructive feedback, not criticism.
In addition to the house’s aesthetics, the quality of spaces, the materials being used, the house’s structure and services, it is essential to discuss
Expert advice in areas such as systems design and thermal modelling is key to ensuring they are achieved. While you may suggest the engagement of such sub-consultants and possible candidates, it is the designer’s responsibility to incorporate their input into the design. You should enquire about the outcomes of their work and how this is being incorporated during your progress meetings with designers.
Make decisions about specifications
The specification section of the detailed design will detail the type and quality of every material being used in the house, from the more visible finishes to things that people will never see, such as steel fixing for foundations. There are two key aspects for you to consider with regards to specifications:
- Everyone has a particular idea of the way they want their house to look. This includes the quality of spaces but also the materials that are used. Seek alternative materials and finishes that are within your budget, and spend time understanding their attributes beyond appearance, particularly in relation to health and durability.
- Decisions about some finishes, such as fixtures and fittings, can be left out of the specification and defined later in the process. In order to do that an amount of money know as a prime cost (PC) or provisional sum is set aside by the design team for you to spend on those items later. Discuss any provisional sums with the designer and seek quotes for things like window coverings and floor coverings to ensure the provisional sums are adequate.
How much input you have into the specification will depend on the procurement process you have decided on.
- Custom Design: The specification will be discussed with your lead designer and builder (if they have been engaged at this point) but you make the final decision and can have what you want.
- Design and Build: You will discuss the specification with the builder or developer, and how much input you have will depend on the agreement or contract you have. While there will be some flexibility, the builder may have agreements in place with suppliers which will limit your choices.
- Group Housing: The specification will be included as part of the overall package, and there will be very limited ability to change anything. Any change will carry an additional cost.
Review the tender documents
In a Custom Design project your designer will prepare tender documents for builders to respond to with their price and proposed building process. Before the documents are finalised you should review them with the designers to ensure they align with the project’s objectives and to understand what builders are being asked to provide in their responses.
Once the tender documents have gone out, any changes to the design will have an impact on cost and time. Details such as window placement, lighting and plumbing design are typically finalised within the tender documents, so it is important to note that this point may be the last chance to make any changes to the design.
Tender documents are only required when a selection of builders for the building stage needs to be evaluated. With Group Housing and Design & Build projects the building team is most likely already engaged so tender documents are not necessary. Where a building team does need to be engaged at this stage in these projects, you might not have the option to view the tender documents before they go out.
What to expect from your designer
Refine the design
In this stage, designers work towards producing a set of documents that can be used for building consents, resource consents and contracting processes. They will progressively develop detailed drawings, schedules and specifications that serve as the basis for the construction process. Areas that are being refined include:
- building construction methods, including structural details, insulation and waterproofing details
- building systems such as heating, plumbing and electrical
- internal details such as stairs, bathrooms and cabinetry
- material finishes.
The project develops alongside a cost plan and program of work. As the drawings become more detailed, so will these two documents.
It is the designer’s responsibility to produce all the information necessary to communicate the project to others in an effective way. This will be essential for a smooth consenting process and will avoid misunderstandings with the building team during construction.
Assess the design against the Design Brief and Vision Statement
Forgetting about the overall vision that was captured in your Vision Statement and Design Brief becomes more likely as the project advances and designers get caught up in resolving the details of the design. Keeping these documents at hand and revising them periodically to ensure your objectives are being met will result in a satisfactory outcome for both you and the design team. It is also important to check that time and cost targets are being met, to understand and document any areas where they are not, and to document any changes to the brief and the impact of this on the timeframe or budget.
Prepare drawings for tender
In a Custom Design project, tenderers will base their proposals on the set of documents containing drawings, specifications and the program of work. The level of detail contained in them should be sufficient to understand the project without allowing for personal interpretations or ambiguity. A high quality design process should result in an efficient and smooth-running tendering process.