Integrated Design Process
Bunting Coady Architects' approach to consultant coordination and resource allocation centres around the Integrated Design Process (IDP). The purpose of the IDP, a process we pioneered, is to facilitate the smooth delivery of complex projects with high performance targets. This systemitized approach ensures that results are high performance, cost effective designs.
Our entire team is fully committed to the Integrated Design Process. Bunting Coady Architects has worked effectively with many consultants on a number of projects utilizing the IDP.
- Orientation and Massing
- Site Design and Water
- Envelope
- Ventilation
- Lighting and Power
- Heating and Cooling
- Materials
- Quality Assurance
Orientation and Massing
Design Assistance Role
In this phase, the Building Owner, the Architect and the Energy Engineer work together to develop the most appropriate form of the building and to develop preliminary fenestration strategies. The building is modeled on a computer software program that will analyze its basic thermal and day lighting performance and simultaneously act as a design massing tool to assist in the design process.
Goals
The goals for this phase are to meet performance criteria for the site and building and for basic energy loads. The goals for active versus passive solutions are discussed and defined at this stage.
Team Players and Roles
The Team involvement at this stage is as follows:
The Building Owner will be asked to set site restrictions and communicate program goals for the building.
The Architect will develop massing options in concert with the Building Owner and the Energy Engineer.
The Energy Engineer will simulate the building massing and the optimal orientations on the site and test results for energy performance.
The Mechanical Engineer will assist the Energy Engineer in reviewing the loads and in planning preliminary mechanical strategy.
Results
Based on the results of the preliminary simulations, aesthetics and building program criteria, an optimal shape for the building and its location on the site will be determined.
Site Design and Water
Design Assistance Role
The Team is introduced to the site as an ecosystem that filters and oxygenates the air supply, retains water and replenishes ground water and provides ambient cooling to the building. The use of recycled materials in site finishes and furniture is explored.
Goals
The objective at this stage is to rationalize the site design in terms of requirements for parking and pedestrian access along with considerations of the site as an eco-system contributing to the sustainability of the project as a whole. The building should be successfully integrated into the site design and the site design should contribute in a positive way to the program goals and objectives.
Team Players and Roles
The owner defines the site parking, landscaping and feature area requirements.
The Architect takes the lead to investigate options for alternatives to asphalt areas, shade and landscape areas to enhance the fresh air ventilation strategies and water reuse and reduction strategies.
The Landscape Architect is brought in at this time to investigate rainwater reuse options, low water plant species and drop irrigation systems.
The Mechanical Engineer reviews the proposed plumbing systems to reduce the water use in the building, and investigates grey water reuse potential.
Special site features are examined for their potential to enhance the sustainability of the Project. Natural waterways, forested areas and fields may provide cooling, water filtration and fresh air.
Parking and vehicular disruption is minimized.
Results
The site and building complement each other and are designed to optimize the energy efficiency and environmental sustainability of the project.
Envelope
Design Assistance Role
During this stage, the Team takes the basic building shape as developed during the first stage, and develops the envelope detailing to determine the best possible ratio of wall to window, glass and shading options, insulation values and high performance building technology applications. At this time, details of the building shape will be refined and further developed with the input of the team. Also, the building assemblies are reviewed for thermal bridging characteristics and assembly detailing and materials are developed.
Goals
The strategies usually explored during this step include increasing the performance of the glass to a reasonable, cost effective level, examining the performance levels of the mullions and frames, investigating sun shading options that may have been indicated by the first stage simulation exercise, and examining insulation values to optimize their effectiveness.
Team Players and Roles
The Team involvement expands slightly at this stage to include the Electrical Engineer.
The Building Owner sets the window, ceiling and height minimums. At all times, concern for the owners performance needs are paramount.
The Architect develops elevations and sun shading and glazing options.
The Electrical Engineer examines day lighting potential.
The Energy Engineer simulates the building to determine the best combinations of window size, insulation and sun shading based on the common goals of the team.
Results
The building now has a shape and the elevations are roughed out with areas of window and sun shading developed. The wall detailing and insulation strategies are developed.
Ventilation
Design Assistance Role
Ventilation is the key to a healthy building. Poor ventilation strategies can result in either too much energy being wasted to ensure adequate ventilation, or conversely, too little air being provided to improve overall building energy performance. It is in this area that the integrated design approach realizes real rewards. The Team is exposed to ventilation design options including source reduction options for improvements in indoor air quality and energy efficiency.
Goals
The goal for this phase is to improve indoor air quality while maintaining energy efficiency.
Team Players and Roles
The Owner is asked to set optimum qualification CFM targets for the building. The group discusses the issue of ventilation effectiveness and realistic ventilation performance targets are set.
The Architect selects materials for the building that reduce the potential for off gassing of volatile organic compounds and do not encourage particulate accumulation or microbial growth in the building. Strategies to improve the outside air quality are also reviewed by the Architect. The Architect reviews shade trees, and exterior planting options.
The Mechanical Engineer refines the system to maximize both ventilation performance and energy efficiency, taking care not to introduce systems that may support microbial growth.
The Energy Engineer simulates the building with the optimized system in place. Refinements to the ventilation rates, the building system design and the interaction of the building components continues.
Results
The building massing accommodate natural (passive) ventilation. Strategies incorporated into the building include limited floor plate depth to allow cross ventilation, passive stacks in the plan (chimneys) to create negative pressure and a designed response to wind direction and building height. The architecture is refined to allow for control of positive and negative pressure passively throughout.
Window and vent and chimney designs support ventilation strategies.
The location of trees and plants filter air intake locations.
Lighting and Power
Design Assistance Role
Once the building shape and general window and sun shading strategies are known, the amount of interior lighting required can be determined. It is important to reduce lighting loads as these are a significant portion of the energy consumption of buildings, both because of the power to the lights and because of the cooling load they generate.
The strategy for this stage of the work is to optimize daylighting with light shelves and clerestories while maintaining the cost efficiencies of the Project. Reducing the lighting load reduces both power consumption and cooling requirements.
Goals
The goal is typically to reduce the watts per square foot and to keep the ambient level of lighting up so there is no need for task lighting at the desk level. This reduces the potential for uncontrolled plug loads in the building. The viability of actively controlling plug loads is also discussed at this stage.
Team Players and Roles
The Design Team works together. This time the Owner is asked to clarify the exact lighting performance levels needed, qualitatively, not quantitatively, for the use of the interior space in general. Any special power loads are identified at this time, including the potential for unknown equipment.
The Architect develops the lighting grid along with the Electrical Engineer. Some modifications to windows and or depth of space may be undertaken at this time.
The Energy Engineer models the resulting lighting loads and refines the energy use profile of the building.
Results
At this time, the building systems are beginning to take shape. If the lighting is a suspended system, it will require a greater floor to ceiling height. If this is the case, the Structural Engineer may become involved. Lighting quality is optimized in an energy efficient system.
Heating and Cooling
Design Assistance Role
The building heating and cooling loads have been outlined by this time as the general shape, power load, and heat from lights is now known. At this point, the team investigates the building heating and cooling systems. The team is assisted in selecting the design approach for either an active technological or a passive architectural energy efficient building solution.
Goals
The required size of the HVAC plant and secondary systems will have been largely pre-determined by previous design issues. The goal is now to select a HVAC configuration which meets functional requirements while cost effectively minimizing energy use.
All major components of the building have been defined. A life cycle cost analysis is done at this stage to define the incremental capital cost over standard construction for the project type, the anticipated energy savings, and the pay back period.
The goal is to determine the most reasonable strategies to incorporate into the contract documentation phase. Measures that reduce energy will be costed independently from those that are environmentally based. Ideally, the efficient and improved building should cost less to build and should save some energy as well. These cost savings can then be applied to environmental impact measures that may not have a dollar value benefit.
The goal is to keep the life cycle costing process simple so that it can easily be applied while still meeting the information requirements of the owner.
Team Players and Roles
The Energy Engineer, assisted by the Mechanical Engineer, will have assumed a base building type of system for the purposes of simulating and modeling building performance.
The Building Owner will discuss preferred systems at this time. All building performance criteria that affect the heating and cooling system design are reviewed. The option of eliminating the heating and/or the cooling due to the high performance envelope is also reviewed at this time.
A system that meets functional requirements as well as energy performance targets is developed by the Mechanical Engineer, with input from the Energy Engineer.
The system is reviewed and refined by the Building Owner.
Once the system has been optimized and simulated by the Energy Engineer, the Architect may be asked to make adjustments to the envelope and the glazing systems to respond to the refinements in the heating and cooling strategies.
The building is zoned for mechanical systems by the Energy Engineer in consultation with the Mechanical Engineer and the Building Owner.
Results
Mechanical system design is approximately 80% complete. Any exotic technologies are costed. The mechanical system is designed to assist the building self-balance.
Materials
Design Assistance Role
Once the building has reached this stage much of the preliminary design work and the detailing normally associated with the first stages and some later stages of working drawings is already done. The team has created a building that operates efficiently and is cost effective. The team is exposed to information regarding building materials and their effects on indoor air quality as well as their embodied energy content.
Goals
The last step before the building is cost checked is the final selection of materials for the building. This is done as part of the Design Team Facilitation Program for two reasons.
First, the materials are selected to reduce or eliminate those that break down into fine particles, those that off-gas, and those that might reduce the energy efficiency of the building by causing thermal bridging or allowing heat gain or loss. This first consideration is building performance based, focusing on the energy and ventilation requirements of the building.
Secondly, the materials are selected with a view to their embodied energy. This is a developing area of current research. Materials are selected, when possible, to have a low embodied energy, a recycled content and a potential for recycling in the future. Building longevity is also a consideration at this stage and structural elements are tested in this regard against cost criteria.
Team Players and Roles
This portion of the work is normally undertaken by the Owner, Architectural and Structural members of the Team, with other members providing information on an as requested basis.
Results
The interior finishes of the building are selected to support clean air initiatives. The building is ready for preliminary costing.
Quality Assurance
Design Assistance Role
Once the building is defined, it is costed. If the Team has been rigorous during its analysis of design options, the resultant building should not cost any more to build than a standard building, while operating in an integrated way to optimize energy efficiency and enhancing environmental sustainability.
Goals
To ensure that the building operates the way it was designed, a final key step in the process remains. Originally called commissioning, this step is now called "quality assurance" as it involves the entire team ensuring the quality and integrity of the entire building.
Team Players and Roles
Each consultant is asked to prepare a section in the base building specification calling for inspections and testing of critical design items during construction. A checklist may be prepared to assist the contractor in prioritizing and understanding some of the advanced building technologies.
The key to the success of this step is to keep it simple. The specifications should read like all others, without a special commissioning section that will surely raise the cost of the building. The existing team takes a little time to spell out exactly what they will be looking for on site, to make the contractor's job easier.
The Building Owner and/or Developers Operations and Maintenance people are asked to work with the team to develop clear operating instructions and to set up the operations and maintenance manual requirements for the building. Where the requirements are not simple, training will be provided.
The Owner is highly involved in this stage, clarifying and communicating needs for the future handover of the building.
The key functional energy and environmental performance criteria must be documented throughout the design process to provide quality assurance terms of reference and commissioning performance objectives.
Results
The contract documents contain requirements for inspections, reporting, training and manuals to ensure optimum building performance.