Case Study Four - Post Occupancy Evaluation
Addressing our clients' concern on the functional requirements and energy consumption of recently completed building projects, we adopted a Post Occupancy Evaluation (POE) approach, which is a management tool tailor-made to evaluate performance and assess effectiveness of the sophisticated building services (BS) system after tenant occupancy. Generally, POE focuses on operational performance monitoring and handover of the project, energy review conducted for the project and new technologies evaluation.
POE encompasses continuous and extensive stakeholder engagement, to ensure building facilities are functioning as the original design intent and comprehensively utilised to fulfil client’s demands. It is an evaluation technique for technological effectiveness, facilitating communication between stakeholders, avoiding repeated mistakes in future considerations, and collecting meaningful data. During the POE, fine tuning of systems was carried out addressing comments made by occupants. An energy review was also conducted with a view to identifying and proposing means to achieve energy efficiency and conservation as well as to recommending good energy saving housekeeping practice.
The following are the potential benefits associated with the implementation of POE to all stakeholders.
- Information collected to facilitate informed decision making;
- Lessons learnt to avoid future repeated mistakes;
- A yardstick to check against whether the system has performed to the design objective;
- A tool to evaluate the effectiveness of any new technologies installed there and then make recommendation on their future uses;
- Improvement to the building environment that enhances the efficiency of the occupants;
- Facilitation of communication between all stakeholders, such as clients, building management and operation & maintenance personnel; and
- Facilitation of any changes (for the better).
POE also helps to facilitate a smooth handover of the BS systems to the end users and maintenance party and allows them to have a better understanding on the design intent and operational condition of them.
Since 2006, eight building POE projects have been conducted to demonstrate the relevant procedures, performance and effectiveness of a POE exercise.
The POE Experience
The Project comprised of a high (43-storey) block and a low (14-storey) block interconnected at podium level. This POE work was completed satisfactorily in 2006. Three POE teams with representatives from building designers, building occupants, Energy Efficiency Office (EEO)4 and building maintenance offices were formed, and agreed on the POE exercise to be commenced with an initial client satisfaction survey to solicit occupants' feedback.
By carrying out POE in this project, we comprehensively reviewed the building service system performance and fine tuned settings of building services equipment if necessary, such as reliability of Air Conditioning Installation, power quality monitoring, and ventilation effectiveness of the Basement Carpark. We could ensure that the building service systems provided are able to match the client’s operational need and that the systems are operating in an energy efficient manner. With the full implementation of various Energy Management Opportunities (EMOs), as identified in POE, since April 2005, it was observed that there had been a significant saving on annual overall electricity consumption.
Apart from the above fine-tuning work, liaison with the building management and occupants was carried out with a view to identify any supplemental or improvement works required to meet with their actual operational need.
Meanwhile, the POE teams have evaluated performances of two new technologies installed in the project, Service-on-demand (SOD) escalators and power harmonic filter. Both are concluded to be promising effective measures. SOD escalators helped in reducing about 30% of the total electricity consumption of the escalator installation.
Our efforts in these areas were well received by the client after implementation of POE. The main feedback was commendations on the new technologies installed for enhancement of building energy efficiency and requested the extension of POE period to at least 18 months after the building occupation. Some common issues encountered during the initial post handover in a newly completed building were also identified through this POE exercise.
POE is becoming an integral part of ArchSD's ambition to strive for systematic continuous improvement and ongoing stakeholder dialogue.
4EEO was established under Electrical and Mechanical Services Department of HKSAR Government to promote energy efficiency and conservation in Hong Kong.