Post Occupancy Evaluations  

Introduction

"Lessons Learned" is a common concept in the practice of designing and constructing buildings. Typically, a building is built, the project is revisited after completion to find out what worked and what did not work, and the lessons are applied by continuing what worked and avoiding what did not. The lessons should change continually, as old lessons are incorporated and inculcated into an ever-improving professional practice, and new, more nuanced lessons are identified and added. These lessons are shared through a means and a culture to assure that the lessons are not simply identified, but learned and turned into more successful practices. Every lesson learned turns the curve towards more successful buildings.

The process of identifying these lessons in existing buildings is commonly referred to as Post Occupancy Evaluation (POE). Typically, the building owner contracts with a firm or individual experts who were not involved in the original design or construction, to evaluate the building's successes and deficiencies after occupancy. This requires that the building be occupied through at least one, and preferably several, heating and cooling cycles.

The POE is not conducted to grade the building or develop recommendations for the solution of identified deficiencies. These are usually accomplished through separate building assessments. The cause of the deficiency is identified so that lessons can be compiled for the owner in order to change practices and criteria to eliminate the problems in future buildings.

In the building life cycle, the POE is applicable at various stages:

• Lessons learned from Post Occupancy Evaluations of best/similar buildings inform briefing/programming of new buildings.
• Designs are reviewed in terms of lessons learned from Post Occupancy Evaluations.
• New buildings are evaluated in their first few years, for fine-tuning, to inform similar projects, and for quality assurance.

The POE team evaluates the building through a series of inspections/walk-throughs of the building to investigate elements, systems, and subsystems through observation, recording of performance metrics, and interviews with various building stakeholders.

Stakeholder groups should include: individuals who created the building through design and construction, those who manage, operate and maintain the building, and those who occupy and utilize the building for various activities including work and pleasure. These specifically include:

• Employees providing a service in the buildings (occupants, staff, professionals, etc.)
• Clients who visit buildings to receive a service (customers, shoppers, students, prisoners, patients, tenants)
• Professionals who provided the final building(s) (architect, engineer, builder etc.) and those who manage, operate, and maintain the buildings (building managers, tradespeople, cleaners, system operators etc.)

The final goal of the POE is broadly measured by increased productivity and performance of the building, both of which can result in a range of reduced costs including:

• Staffing/productivity costs through reduced staffing levels, improved morale, and more efficient workspaces and processes resulting from enhanced telecommunications technologies.
• Utility costs through systems optimization to provide more efficient mechanical and lighting systems.
• Water costs through reduced water usage by using improved and more efficient irrigation, water features, and plumbing fixtures.
• Landscaping costs through reduced landscaping replacement, and maintenance.
• Maintenance costs through lower required staffing/time requirements through reduced relamping, filter replacement, and window washing etc.
• Janitorial costs through reduced staffing/time requirements by using improved finishes, equipment/supplies storage, and lower maintenance components.
• Mechanical costs through reduced equipment replacement and servicing by the selection of improved systems and equipment with increased service life.
• Repair costs through reduced need for expensive vendor repairs caused by custom products and equipment with limited local expertise.
• Replacement costs through reduced costs of replacing poor qualify systems and equipment and inefficient replacement accessibility.

Description

The basic elements of a POE include:

• Determination of the Purpose and Objectives of the POE
• Identification of Building Elements and Systems to be Evaluated
• Determination of Metrics to be Evaluated during the POE
• Development and Review of Building Occupant Questionnaire
• Physical Evaluation of the Facility
• Conducting Facility Occupant Interviews
• Development of POE Report

They are each discussed below.

Determination of the Purpose and Objectives of the POE

The POE Team should conduct initial meetings with the owner's on-site and operations personnel to ensure that the purpose and objectives of the POE are documented and understood. The initial meeting should include a briefing by the on-site personnel, who provide an overview of the project and its perceived successes and shortcomings.

The POE Team and on-site personnel should finalize the schedule for conducting the interviews, reviewing on-site documentation and conducting the walk-through with an emphasis on identifying areas of primary interest, areas that are restricted from the walk-through, and establishing a walk-through protocol, including the use of photography, measurement devices, etc., and revisits by selected Team members for more detailed observations. It may be necessary to conduct off-site interviews via videoconference or conference calls if key personnel are not located near the project.

Identification of Building Elements and Systems to be Evaluated

The POE Team, in consultation with the owner, should identify the building elements and systems that will be inspected and evaluated during the POE.

The site and exterior environment should be evaluated to determine the ease of access by pedestrians, employees, service and visitor vehicles; the operation of security features of physical access control at entrances; the function of the perimeter barriers such as vehicle barriers, bollards, stanchions, fences, etc.; impacts of the facility on local traffic; use of public transportation; availability of parking; access by persons with disabilities; use of on-site energy resources; site features that conserve energy and reduce adverse environmental impacts; landscaping, irrigation systems, site hardscapes, and water features.

Architectural planning and configuration/adjacency issues should be evaluated including: observing entrances and vestibules, circulation, and vertical transportation for persons and materials, public spaces, main lobby and atria, secured areas, private spaces, service areas including loading docks and processing areas, and adequacy and effectiveness of building wayfinding signage for all users.

The building envelope should be evaluated including: the inspection of exterior walls, fenestration, doors, ceilings, soffits, roofing, etc. for thermal transmission, moisture penetration, air leakage, control and access to daylighting and views, sound transmission, impacts on security or safety, energy management, and other functions.

The structure should be evaluated, including: an analysis of its present condition and resistance to extreme winds, floods, seismic activity, and blasts.

Mechanical heating, ventilation and air conditioning (HVAC) systems should be evaluated including: the inspection and analysis of the central heating and refrigeration plant, air handling units (AHUs), terminal units, hydronic systems, and other system components, thermal and Indoor Air Quality (IAQ) conditions at the building's perimeter and interior zones, and the ease of use and effectiveness of control systems, sound and vibration control from HVAC operations, and Building Automation Systems (BAS), including monitoring and control.

Plumbing systems should be evaluated including: observing fixture quantity and performance, water consumption and reuse and efficiency of heating and distribution of domestic hot water.

Lighting and electrical systems should be evaluated including: the observation and analysis of artificial and natural lighting illumination levels, glare control, availability of views to the exterior, means of control and conservation of energy and ease of maintenance.

Fire and life safety systems should be evaluated including: its coordination with security and physical access control measures.

Security systems should be evaluated including: the inspection of perimeter and entrance security, intrusion detection, security camera system, and command center operations.

Determination of Metrics to be Evaluated during the POE

The POE Team will identify and determine the information to be collected and metrics to be evaluated during the POE walk-through. An example of the type of information and metrics to be collected is shown in Table 1.

Development and Review of Building Occupant Questionnaire

A standard questionnaire should be developed and provided to the building occupants to solicit their personal evaluations of their individual workspaces and the overall building. The survey should ask for their satisfaction with the functionality, circulation and attractiveness of the building, and their satisfaction with the thermal, acoustic, lighting, cleanliness, and maintenance aspects of the building. The survey should ask for their ratings on specific aspects and examples of their satisfaction or dissatisfaction. The survey results should be combined to provide an overall satisfaction/dissatisfaction level of the building and highlight areas that should be further investigated by the POE team.

Physical Evaluation of the Facility

The POE Team should conduct a walk-through tour of the property accompanied by knowledgeable representatives of facility management, operations, and/or the original construction project manager. Team members should document as appropriate with photographs, measurements, and other means to support the observations for the written report. The following is a suggested typical scope of a POE walk-through. It should be modified to suit the facility and its environment, including adjacent buildings, streets, and other features potentially impacted by the facility.

• Exterior Site including landscaping, exterior hardscape, surrounding and adjacent property, rights of way with attention to the function of the building in such matters as physical security access control of vehicles and pedestrians.
• Functional Spaces and Interrelationships in terms of their service/mission capacity and their capabilities in supporting the mission of the facility.
• Circulation and Wayfinding should be observed in as many areas as possible, including public spaces such as lobbies, corridors, elevators, and stairs. Also include service areas, such as loading docks, freight elevators, and routes or pathways needed to transport large maintenance and repair items from receiving or storage to point of use, secured pathways such as for prisoners in courthouses, and other features.
• Building Enclosure should be observed for signs of abnormal thermal transfer, as well as moisture or air leakage. The fenestration and daylighting should be observed for quality of light entering the building, for views, and for control of excess sun load, glare, and reflections into the environment. Building envelope issues (exterior enclosing walls, including doors, fenestration and other openings; roofs, soffits or overhangs; and construction over underground parking, vaults, and other spaces) should be observed inside and out, and discussed with facility operations and maintenance personnel as well as with tenants and others who may have anecdotal information revealing issues with the enclosure.
• Indoor Environmental Conditions should be measured in selected areas during the walk-through. Primary observations by the POE Team should be qualitative and focus on judgmental assessments of documented requirements. Qualitative measures may be recommended because of the observations during the walk-through. As a minimum, the following conditions should be observed:
• Acoustics: Noticeable sound and vibration levels, especially in critical areas
• Lighting: Unusual and/or distracting illumination levels or glare issues, including transition from exterior to interior, any occupied spaces where sharp contrast or glare might result from windows or lighting fixtures, and where surveillance or security is of concern
• Thermal: Noticeable hot/cold zones or air distribution (e.g. ventilation) patterns
• Indoor Air Quality: Noticeable odors, presence of moisture or stains (e.g. mold), dust, and other contaminants, especially in areas where health, safety, or security is of concern
• Accessibility, Operability, or Maintainability Issues should be observed regarding the building envelope, air handling units, and central plant installations, as well as spatial allocation for maintenance and methods required to clean, repair, and maintain the components.
• Control Systems and Building Automation Systems (BAS) should be observed regarding on-site control and management, remote control and management, and interoperability.
• Plumbing Systems should be observed regarding fixture performance, and condition of domestic and sanitary piping systems.
• Electrical Systems should be observed regarding arc flash protection, protection of switchgear, transformers, and emergency generators from flooding, availability of emergency and redundant power systems, and management of lighting and power control systems during occupied and unoccupied periods.
• Fire and Life-Safety Systems should be observed regarding deviations with code requirements, and to the performance of the interface with the BAS.
• Security Systems should be observed regarding space allocation and environmental conditions for 24/7 operations.

Conducting Facility Occupant Interviews

The POE Team should conduct interviews with building occupants and maintenance/operations staff, landscaping staff/contractors and janitorial staff/contractors. To help obtain a free flow of information, it is recommended that:

• Tenant representatives should be interviewed separately from other tenants and from property and operations management.
• Project management should be interviewed separately from design and construction teams.
• Design and production architects should be interviewed separately.
• Consulting MEP engineers (i.e. HVAC, plumbing, power, lighting, communications) and other consultants (e.g., BAS, energy, safety, security, acoustics, Guiding Principles, LEED, etc.) should be interviewed separately from architects and contractors.
• The General Contractor should be interviewed separately from the architects and engineers.
• The Construction Manager should be interviewed separately from the designers and contractors.
• The Commissioning Agent should be interviewed separately from the construction manager and the designers and contractors.

At the end of the on-site visit, the POE Team should conduct a closing meeting with operations staff to present an overview of specific issues observed for their comment.

Development of POE Report

The POE Team develops the Facility Post Occupancy Report. The POE Report should be concise and based on the identification of high and low levels of performance, as well as the documentation and substantiation of the underlying reasons that supported these levels. Data obtained and observations made by the POE Team before and during the site visit should form the basis of the POE. Results of this evaluation should be presented in a standard report format to allow comparison among buildings, and the format may be adjusted to suit the specific purpose and objectives of the POE.

Examples of lessons learned from a POE report are shown in Table 2.

Application

The following example describes how a typical POE is conducted, based on an amalgam of a large number of POEs performed by the National Institute of Building Sciences (NIBS) for the General Services Administration (GSA) and the Department of Veterans Affairs (VA).

Selecting the POE Team

Building owners should select a POE team comprised of appropriately qualified members with the necessary past POE experience to perform work of a similar nature and scope.

At a minimum, the POE team should be comprised of four or five members including a team leader, and experts on architectural systems, building envelope/structural systems, mechanical/plumbing systems, and lighting/electrical systems.

The team leader/architectural systems expert examines the facility in terms of:

• Site/exterior environment
• Circulation, lobby, atriums, loading docks
• Wayfinding, including signage
• Building function
• Functional interrelationships (capacities and capabilities)
• Anti-terrorism protection strategies
• Security systems

The building enclosure/structural systems expert examines:

• Structural systems
• Building envelope (acoustics, air and water leakage) (walls, fenestration, doors)
• Roofing

The mechanical/plumbing systems expert examines:

• Thermal conditions and measurement
• HVAC systems
• Plumbing systems
• Fire and life safety systems
• Building Automation Systems
• Indoor Air Quality

The lighting/electrical systems expert examines:

• Artificial lighting (illumination, glare, control, maintenance)
• Natural lighting (illumination, glare, control, maintenance)
• Electrical systems

Organizing the POE Schedule

The POE team should develop the POE schedule in consultation with the facility owner. Typically, conducting a POE on a building of 200,000–400,000 gross square feet requires two full days. Evaluating larger buildings may take longer, depending on the number of non-repetitious floors.

A typical POE first day schedule includes an initial meeting and interview with the building manager, followed by a team review of building documentation which includes:

• Construction Documents (As-builts, specifications)
• Program
• LEED Report
• Utility Records / Metering Records
• Commissioning Report
• Design Reviews
• Surveys and Evaluations that were completed
• Tenant Guidelines

Following the review of the building documents (sent to the team before the actual POE to save time on site), the POE team usually conducts a total facility walk-through that includes direct observation and measurement of performance metrics.

The second day of the POE will typically include interviews with the building occupants and building staff/contractors. The interviews take approximately 30 minutes each to gather both facts and impressions of the facility. The team should inquire about the appropriateness and satisfaction with the site location, including discussions regarding access, accessibility, parking, public transportation, and other amenities. The appropriateness and sustainability of the landscape should be determined, including the use of native plants, irrigation, watering efficiency, and resource allocation required for landscape maintenance. The durability and maintenance requirements of the exterior elements should be determined, including pavement, plaza, exterior stairs, and water features.

Concerning the building itself, the team should determine satisfaction and functionality of the layout, including appropriateness of its room sizes, adjacencies, circulation, restrooms, service areas, and wayfinding. Materials also need to be considered. The team should examine the durability of exterior and interior materials, potential problems with water penetration and moisture migration, and the fitness of interior finishes and flooring, including for the maintenance and cleaning of the building's exterior and interior.

The team should inquire about the building systems' energy performance including: the availability of performance data, problems during heating/cooling seasons, performance of high-efficiency equipment and maintenance/service issues, availability and understanding of energy analysis documentation, and functional testing and metering. The building's ability to provide thermal comfort and indoor air quality should be determined, taking into account the efficacy and efficiency of air movement and temperature control, moisture control, and solar gain issues. The building's water usage performance should be determined and discussed, including: the availability of water usage data, conservation and sustainability of water usage, operation of high-efficiency fixtures, irrigation water usage, and storm water management. Finally, the appropriateness and satisfaction with artificial and natural lighting should be observed and determined including: illumination levels, location of lighting, use of task lighting, daylighting and shading, and lighting/daylighting control and training.

After the interviews on the second day of the POE, individual POE team members may need to investigate specific building spaces or systems if they have additional questions about performance. At the end of the second day, the POE team presents its findings of major issues (both successes and deficiencies) to the property management team and gathers any further information specific to these issues.

Emerging Issues

As the workplace continues to evolve at an ever-increasing pace, evaluators should be cognizant of emerging performance issues that should be incorporated into POEs. At the time of this writing, emerging issues included evaluation of workplace productivity based on the building design, and evaluating the safety of the building to prevent the spread of the COVID–19 virus.

Workplace Productivity Evaluation

Employee productivity, also called workplace productivity, is an assessment of an employee's or a group of employees' efficiencies. It is evaluated by looking at the total workforce or employee output in a given time in a given physical configuration.

Today's work style varies radically from work practices of 20 years ago. Organizations are less hierarchical, processes are more collaborative, and mobile technologies provide people with robust tools to perform complex work anywhere, at any time. Moreover, the next generation workforce has very different norms and expectations about the workplace compared to expectations of prior generations. In the past, most owners viewed the workplace as a static physical container for work that reinforced status through rank-based standards.

This view is completely out of step with today's world of mobile devices and fluid team-based organizational processes. The workplace is now an integrated system of space and technology that enables work, wherever it occurs. It takes integrated planning, and a change management approach to optimally leverage space and technology to lower costs and positively impact the performance and satisfaction of workers. These new enhanced productivity elements could include:

• Workspace configurations
• Telecommunications spaces
• Teleconferencing spaces
• Agile workspaces
• Enhanced circulation
• Adjustable furniture and conference tables
• Communications infrastructure, and probably most importantly
• Collaborative work environments

Collaborative work environments should provide universal connectivity, flexible interiors, as well as an emphasis on functionality and support space to promote person-centric services.

Effective collaboration in the space entails both individual, focused tasks and interactive group work. Accordingly, collaborative work environments require spaces, furnishings, and technologies that support both individual focus and group interaction, while also facilitating transitions between these activities. Finding the right balance and types of support for individual and group work requires an understanding of both social and cognitive processes.

The social components of collaborative work effectiveness involve three related types of social behaviors: Awareness, Brief interaction, and Collaboration.

Awareness involves knowing what is happening in the surrounding space as well as the meaning of events and actions. Processing of this information is primarily through peripheral channels and is used to maintain an on-going knowledge of others' locations, activities, and intentions.

Brief Interactions are largely unplanned and occur as part of the natural behavior system of knowledge work as people ask questions, check facts, set up meetings, and joke with colleagues during the workday. Brief interactions aid information flow, spark new ideas, promote internal learning, and aid the development of working relationships.

Collaboration and its successful implementation vary according to the nature of the work. Key considerations include:

• On-going communication needs. The need for rapid, continuous information sharing, group problem solving, monitoring progress, and pressures for reduced product/project time are factors favoring easily accessed group workspaces, shared information displays, and dedicated project rooms.
• Cognitive complexity of the group task. Multidisciplinary understanding and complex problem solving are likely to require group technologies and tools, including information displays, surfaces for tracking progress, shared databases, and visualization technologies. Spaces specifically designed for collaboration include project rooms, informal teaming spaces, open bullpen workstations, and the high technology mobile workspace.

During the POE, areas of investigation to evaluate the productivity enhancing features of the building include:

• Sound absorption. It may be well worth paying the small cost increment to obtain a ceiling that is at least 80% sound absorptive (as opposed to the typical 60% sound absorptive) in open office areas where noise level control is important in allowing increased focus on the work effort.
• Lighting. Well-designed lighting can create a comfortable and inviting workplace with appealing ambient lighting to reduce harshness and glare. Areas lit from sources that are mostly indirect and reflect light off of the ceiling, paired with adjustable task light at the desk, offer spaces much more conducive to concentration and focus.
• Careful wall design. Walls are the primary element involved in planning an interior. They can be inflexible, block light, impede communication, and take large amounts of natural resources to construct. Careful consideration of wall function, placement, composition, and attributes are among the most important design decisions that will provide spaces that invite cross communication and staff interaction.
• Furniture selection. Furniture should be integrated and complimentary to the overall architectural design of the space. Furniture should be considered an investment and selected for its design, durability, application, re-usability, minimal maintenance, and functionality, in addition to providing a comfortable seating and working arrangement for the occupant.
• Task seating. Task seating should be provided with adjustable components so individuals can tailor them to fit their bodies. Furniture that is well designed can create such a desirable look and feel for the individual environment that a decrease in space may be easier for an employee to accept. Because space and employees have higher related costs than furniture, buying higher quality/well-designed pieces that occupy less space will be more cost-effective than large, un-ergonomic and ill-considered pieces.


System furniture configuration can cause cleaning problems, especially at voids between workstations at building columns.
Photo Courtesy of NIBS/GSA POE Team

• Systems furniture. Systems furniture should be selected to support work processes, understanding that less product is better from environmental, inventory control, and simplified planning points of view. More freestanding, movable options in a task environment allow individuals or small groups to easily modify their space to meet specific needs.
• Individual vs. group arrangements. Individual workstations are often selected to support the individual exclusively, without considering balancing the support requirements of the group or the enterprise. In other words, the preference of the user may inhibit the overall group if it stifles communication or collaborative behaviors.
• Privacy. Users typically request the maximum degree of privacy whether or not it is necessary. Often the key to controlling noise disruption is making people responsible for their personal behaviors rather than erecting barriers to block the noise. Traditional high partitions in large areas of open space do not control noise, give a false sense of acoustic privacy, inhibit quick communication, and discourage interaction.
• Power and data. These are extremely important but may be limited to electrical distribution as phones and computers go wireless. Consider how power and data are most easily distributed for access and modification. Let the method of delivery and distribution drive the planning methodology, not the reverse.
• User control. How much control the user has in modifying his or her workspace will affect the design. Variable privacy and mobile elements can give individual users choices. User satisfaction has a direct correlation with the ability to control elements such as task lighting and desk height, which in turn has a direct correlation with increased productivity.
• Equipment and power. Equipment, appliances, and technology are critical components of the workplace. These items need to be integrated into the overall workflow and design sequence of the space. Location, creating access, specifying, and integrating the equipment are critical parts of the overall workspace design process. Computers, printers, fax machines, copiers, coffee makers, dishwashers, icemakers, and refrigerators all require specific power/data access, wire management, surfaces, and/or enclosures to function effectively. It is important to provide for power and data in locations that might become equipment locations in the future.
• Flow. Design the space to create a logical flow and sequence in areas that are equipment intensive, including kitchens, break rooms, reception areas, etc.

COVID–19 Evaluation

The 2020 Coronavirus pandemic dramatically affected health and safety concerns within the workplace. Future POEs may well incorporate a component that evaluates the inherent safety of the building in terms of COVID–19 infection as well as conditions for coping with future pandemics. These new POE elements include:

• Checking that the building is ready for occupancy before resuming business operations, including ensuring that ventilation systems in the facility operate properly, reviewing start-up guidance in the current edition of ASHRAE Standard 180, Standard Practice for the Inspection and Maintenance of Commercial Building HVAC Systems, if necessary.
• Evaluating the building's mechanical and life safety systems-including checking for hazards associated with prolonged facility shutdown such as mold growth, rodents and other pests, or issues with stagnant water systems-and taking appropriate remedial actions.
• Increasing circulation of outdoor air as much as possible by opening windows and doors, using fans, and other methods.
• Conducting a thorough hazard assessment of the workplace to identify potential workplace hazards that could increase risks for COVID–19 transmission.
• Implementing recommended engineering controls intended to isolate workers from infection hazards, including modifying furniture and workstations, making changes to the office environment to ensure physical distancing, and improving ventilation.
• Evaluating whether workstations have been moved to maintain social distancing of six feet between employees or transparent shields or other physical barriers have been installed where social distancing is not an option. Chairs in communal seating areas such as reception lobbies that cannot be placed far enough apart should be turned, draped, covered with tape or fabric, or removed completely so that seats cannot be used.
• Evaluating that owners have taken steps to physically separate employees in all areas of the facility, including work areas, meeting rooms, break rooms, parking lots, entrance and exit areas, and locker rooms. Employers can use signs, tape marks, or other visual cues such as decals or colored tape on the floor, placed six feet apart, to indicate where to stand when physical barriers are not possible.
• Ensuring that high-touch communal items, such as coffee pots, water coolers, and bulk snacks, are replaced with pre-packaged, single-serving items.
• Improving central air filtration, increasing air filtration as high as possible, to Minimum Efficiency Reporting Value (MERV) 13 or 14, if possible, and inspecting filter housing and racks to ensure appropriate filter fit, and checking for ways to minimize filter bypass.
• Using portable High-Efficiency Particulate Air (HEPA) fan/filtration systems to enhance air cleaning, or Ultraviolet Germicidal Irradiation (UVGI).
• Ensuring exhaust fans in restroom facilities are functional and operating at full capacity when the building is occupied.
• Generating clean-to-less-clean air movement, by re-evaluating the positioning of supply and exhaust air diffusers and/or dampers and adjusting zone supply and exhaust flow rates to establish measurable pressure differentials.

Relevant Codes, Standards and Guidelines

• ASHRAE Standard 180, Standard Practice for the Inspection and Maintenance of Commercial Building HVAC Systems  ASHRAE, June 2018.
• LEED v4.1
• WELL Building Standard v2

Additional Resources

Publications

• Assessing Green Building Performance: A Post Occupancy Evaluation of 12 GSA Buildings , 2008.
• Enhancing Building Performance by Shauna Mallory Hill, Wolfgang F.E. Preiser, Christopher G. Watson. Wiley-Blackwell, March 2012.
• "Going Beyond the Punchlist: Why Architects Should Embrace Post-Occupancy Evaluations," by Lance Hosey. Metropolis magazine, 2019.
• Learning from Our Buildings: A State-of-the-Practice Summary of Post-Occupancy Evaluation by Wolfgang F. E. Preiser. Federal Facilities Council. National Academy Press, 2001. The evolution of post occupancy evaluation toward building performance and universal design evaluation.
• Post Occupancy Evaluation and Building Performance Evaluation Primer  by RIBA. Architecture.com, 2016.