All multi-occupant spacesMulti-occupant spaces are places of egress, congregation, or where occupants pursue overlapping or collaborative tasks. Multi occupant spaces may be regularly or non-regularly occupied spaces. (like classrooms or auditoriums) must have at least one occupant comfort control. Multifamily housing must also have one control per unit.
For individual spaces or open-plan offices, at least 50% of occupants must be able to control their individual comfort conditions.
Providing thermal comfort control with operable windows is a common way to earn this credit.The credit defines comfort according to the four primary comfort criteriaComfort criteria are specific design conditions that take into account temperature, humidity, air speed, outdoor temperature, outdoor humidity, seasonal clothing, and expected activity. (ASHRAE 552004) identified by ASHRAE 55-2004:
A comfort control meeting the credit requirements needs to only address one of these four. Common ways to meet the credit include installing:
Is a desk fan an acceptable strategy? Some project teams have reported success with desk fans, but it may depend on your rating system.
LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. #1722, 3/22/2007 which applies to NC-v2.2, but not officially to LEED 2009, states that they are not allowed, since the intent of the credit "deals with providing thermal comfort control as an integral part of the building design."
However, Reference Guide Addendum ID# 100000766, 2/2/2011, explicitly applies to LEED-2009 rating systems, and states that "Individual comfort plug-in devices are acceptable for meeting the intent of this credit" as long as they are included in your EAp2 energy model.
You can meet this credit with either naturally or mechanically ventilated buildings.
Projects using natural ventilation need to provide access to operable windows for at least 50% of occupants. Access to an operable window means that an occupant's desk is located within 20 feet of a window to the inside, and ten feet from side to side.
Thermal comfort controls like thermostats are a common way to earn this credit, but make sure you choose a mechanical system that allows for that level of variability.It is more difficult to achieve credit compliance with mechanical systems like forced air because the controls typically serve a large area. You can provide a greater level of thermal comfort with underfloor air distribution that provide easily controlled diffusers.
For constant-air-volume systems that do not allow individual control, you may need to add an additional unit, such as a reheating coil at the diffuser or perimeter baseboard heating, to achieve the credit’s intent.
For mechanically ventilated spaces, previous LEED-certified projects have complied with the credit by providing occupant controls for heating or cooling only. For example, a building providing controls that adjust heat within a certain temperature range can comply with the credit, even if controls are not provided for the cooling season.
Air diffusers provided via underfloor air distribution systems can provide individual comfort control in offices.
Multifamily: For a small unit, you may only need a single control—it can be a window or a thermostat. Most units will require a control in each bedroom and in the living room or other multi-occupant spaces.
Offices: Private offices and open space offices need multiple controls for 50% of occupants. One control in each conference or meeting room.
The IEQ space matrix is a key reference document for this credit (as well as several other LEED credits). Currently in its third edition as of 4/1/2013, the matrix is a spreadsheet that categorizes the spaces from the IES Lighting Handbook, 10th Edition for applicability to IEQ credits. These lists are intended to be used along with key LEED definitions for spaces such as regularly occupied spacesRegularly occupied spaces are areas where one or more individuals normally spend time (more than one hour per person per day on average) seated or standing as they work, study, or perform other focused activities inside a building.. Many questions about this credit can be clarified by reviewing the IEQ space matrix.
It's a good idea but the implementation may not work as well as original conceived. For instance, what if the building manager isn't always readily available? Does everyone have access to his or her number? How many adjustments are possible within your open plan office area? Would there be enough distinct settings to account for controls for roughly half of the occupants in this space?
LEEDuser is aware of one project earning the credit by providing a very detailed narrative. Clearly visible postings were made in the building that helped to clearly communicate the process to the occupants and a phone number was provided for the occupants so that they would have quick access to the manager.
Until a LEED InterpretationLEED Interpretations are official answers to technical inquiries about implementing LEED on a project. They help people understand how their projects can meet LEED requirements and provide clarity on existing options. LEED Interpretations are to be used by any project certifying under an applicable rating system. All project teams are required to adhere to all LEED Interpretations posted before their registration date. This also applies to other addenda. Adherence to rulings posted after a project registers is optional, but strongly encouraged. LEED Interpretations are published in a searchable database at usgbc.org. clarifies this issue, it is likely to depend on specific circumstances. The strategy makes sense from an energy efficiency standpoint, but the intent of this credit is more about individual occupants having comfort controls.
In short, yes. If IEQc6.1 and IEQc6.2 are both pursued then all individual and multi-occupant spaces must be included. LEED reviewers will want to see consistency across these for IEQc6.1 and IEQc6.2.
The matrix includes several space types that have transient occupants, for example: libraries, auditoriums, and transportation terminals. Controls must be provided for these spaces if they are listed as individual occupant or multi occupant and have the corresponding "Yes" in the relevant credit column.
This question is addressed in more detail under IEQc6.1.
Use your best judgment. The matrix states, “exceptions to area use classifications will be accepted on a case-by-case basis for spaces with atypical uses or those in which strategies required for compliance may compromise the function of the space. This is not an exhaustive list. If a space is not listed, project teams should try to find a similar space type and follow that guidance.”
Safety and code compliance have to always come first. You can always try writing a strong narrative to make your case for your project’s exception. However, it’s important to keep in mind that some project types may simply not be well aligned with the credit’s requirements. In that case, it might best to focus your efforts on other LEED credits that are more applicable.
Early during pre-design the owner identifies occupant comfort and control goals in the Owner's Project Requirements for commissioning in EAp1 and EAc3.
Assess your climate and your ability to provide occupant-controlled interventions for different comfort criteria. These may include:
Desk fans are not considered an acceptable strategy according to LEED Interpretation #1722, although USGBC has not officailly applied that Interpretation to LEED-2009 rating systems.
For commercial buildings, systems like fan coils paired with dedicated outdoor air systems can help provide local control to occupants, while reducing first-cost expenses like duct-work.
Including operable windows in the building can reduce dependence on specific mechanical system designs. Positioning as many occupant spaces near operable windows as possible can make this credit easier to achieve.
Some conventional systems typically rely on central control, and multiple controls may be difficult to incorporate. Underfloor air distribution, on the other hand, is designed for flexibility and individual control in a way that naturally supports this credit.
The required comfort control has to address only one of the four primary comfort criteria identified by ASHRAE 55-2004: air temperature, radiant temperature, humidity or air speed. You may address multiple criteria, but aren’t required to do so.
The comfort system does not have to be especially expensive or complex. It may simply be, for example, localized air conditioning with occupant controls.
Providing occupant comfort controls can add some costs, but they can also save money and improve occupant comfort and productivity. Occupant comfort controls allow for the mechanical system to respond to conditions specific to different parts of the building, improving overall comfort while saving energy. Typically, a system under central control is sized and calibrated for the least comfortable space. For example, in cooling season overhead air conditioning is provided for the warmest space, while everyone else under the same AHU feels uncomfortably cold. By providing individual controls, everyone can adjust the cooling or air speed to their comfort needs. This control often directly translates to lower energy costs.
Individual thermal comfort plug-in devices are allowed under IEQc6.2, as long as they are included in the design but not the baseline energy model.
Develop a list and number of all occupied spaces in the building, noting multi-occupant spaces. The number of individual occupant spaces and multi-occupant spaces should be the same between IEQc6.1 and IEQc6.2.
A multi-occupant space is space for group interactions, like classrooms, conference rooms, cafeterias, lobbies, warehouse loading areas, theaters, break rooms, commercial kitchens, retail stores, and exhibit spaces that expect large number of people to gather.
Each multi-occupant space should have at least one comfort control that regulates air temperature, radiant temperature, humidity, or air speed in that room.
For individually occupied spaces, identify the total number of workstations anticipated to be in each space per the project FTE count or based on the estimates listed in the Reference Guide Appendix 1. "Workstations" are referred here as places where full-time occupants spend majority of their time.
How many people per operable window? If using operable windows, locate as many people as possible close to them. Although strictly speaking it may make sense to count one person as needing one operable window, the experience of the LEEDuser team is that the credit has been approved by counting multiple people sitting close to a window as long as a person is within a 20-foot depth and a 10-foot length from one. The operable portion of the window must also be at least 4% of the size of the floor area of the space accessible to a given window, per ASHRAE 62.1-2007. For example, for a 5-foot-long window plus 10 feet on either side the total qualifying floor area would be 25 (5 + 10 + 10) multiplied by 20, or 500 ft2. At 4% of the floor area, the operable window area must be at least 20 ft2. Refer to the Documentation Toolkit for a diagrammatic representation of the window-area-to-floor-area relationship.
How many people per control? Even though the credit calls for individual comfort controls, projects often earn this credit by grouping occupants around a single operable window. Similarly, a single mechanical system control can serve up to two occupants, contributing to the 50% credit threshold.
If less than 50% of occupants have access to operable windows, add more operable windows, adjust the layout, or add ducts, baseboards or diffusers with controls to add individual comfort controls. Run calculations again and redesign till 50% of people have access to the controls.
An open office space is individually occupied where each person has an individual desk and defined space.
Individually occupied spaces are defined as the place where an occupant spends most of their time, such as a private office, reception desk, workstations or cubicles in open-plan offices.
A control can be as simple as a switch to turn air conditioning on or off, changing temperature in a small permitted range using a thermostat, or closing a diffuser to reduce air flow.
Providing comfort controls that allow an occupant to turn a system on only when using the space, and turn it off at other times, supports energy efficiency goals. Whether or not it can contributes to demonstrable energy reductions for EAc1: Optimize Energy Performance is another question. Except for operable windows, this would be difficult to demonstrate.
Note the credit requirement is based on number of occupants for individually occupied and number of spaces for multi-occupants. Only half of the total building occupants must have controls in individually occupied spaces. However, each of the multi-occupant spaces must have independent controls.
For example, an open plan office has 100 desks and 10 private offices, for a total of 110 individually occupied spaces. At least 55 of the people occupying those spaces must have access to comfort controls. The same office also has two conference rooms. Both conference rooms need their own controls.
Facilities managers may have reservations about providing controls to users. The range of control can be limited to a certain range, however, and should be programmed to be reset at least at the end of the day with the building’s typical temperature setback. Be sure that occupants will be educated on how to use controls.
One control per residential unit is required in hotels and multifamily buildings.
Additional controls imply higher construction costs, with additional wiring, and maintenance for uninterrupted operations. There are low-cost options, such as baseboard heating radiators and heat pumps that are easy to operate and provide good local comfort. Compare the upfront costs of better controls to the long-term benefits of higher productivity, better test scores or hotel occupancy, plus savings in energy usage.
Underfloor air or ceiling-air plenum are common systems for allowing occupant comfort control. In addition, they can:
Chilled beams and radiant ceiling panels can provide individual temperature controllability. Given the appropriate climate, internal loads and envelope design chilled beams can be a good fit for this credit, especially if other options like operable windows are limited—for example in laboratory buildings.
In the absence of operable windows, it is difficult to meet the 50% credit requirement unless the mechanical system is designed with zones to provide multiple comfort controls.
Operable windows, although offering some energy and comfort benefits, have some drawbacks. They allow in outside air, which may not be of the highest quality, and also allow in outside noise. The unconditioned air they allow in can affect the operation of mechanical systems.
Operable windows are generally higher in cost than fixed windows.
A mechanical system with more individual controls may cost more than a conventional system. This cost can be offset, though, by lower operating costs, a more flexible layout, and improved occupant productivity.
If using a mechanical system, confirm that the project design is progressing with a system that allows for multiple controls.
Update the count of total individual workstations and those with controls. If the controls do not add to be 50% of total workstations then investigate the potential to add more controls or change the layout to make them more accessible to windows.
Configure the mechanical system so that when windows are open, cooling is turned off to avoid wasting energy. You can accomplish this by hooking operable windows up to wireless sensors that communicate with the cooling system.
Install a building management system that communicates with occupants to open operable windows when outside temperature and humidity are within comfort range as defined by ASHRAE 55-2004.
If using operable windows, make sure the window schedule and all construction drawings include relevant details. Specify windows and window locations that make them easy to operate.
Include all control locations and specifications in drawings and bid documents. Verify that the construction budget accounts for all thermostats, diffusers and a feedback system.
Provide for the commissioning of control and response systems in the commissioning scope for EAp1.
During the construction bidding phase, discuss the schedule to make sure correct control equipment is purchased and installed on time. The controls are only as good as the feedback and response system they are connected to. Explain the control sequence to the subcontractors to minimize confusion.
If value engineering threatens comfort controls, remember their benefits—including energy savings and higher productivity.
Ensure correct installation of all mechanical systems.
Complete LEED Online documentation. Include mechanical system layout with controls schedule and cut sheets.
List all spaces and occupancy types for the project on LEED Online. Mark the kind and number of controls available in each of those spaces. Select “None” if any of those occupants do not have individual controls. The online submittal form will automatically advise on number of required occupants with controls and those that are available.
The commissioning agent should check and verify operation and setpoints of the controls. (See EAp1.)
Educate occupants about the range of control adjustments available. Many air diffusers can open or close the air vent and change the temperature only within a limited range, typically within 5ºF–10ºF of acceptable comfort levels. For example, a heating system may allow a range from 68ºF–74ºF. Comfort controls may not allow larger changes or switching to air conditioning during the heating season, and it is helpful for occupants to understand this. Encourage occupants not to leave windows open when heating or cooling is on.
Train operations and maintenance staff to troubleshoot any problems, particularly if there is a BMS system that responds to user controls, with overrides for end-of-day setbacks.
Incorporate controls into the operations manual and training so that facility staff are aware of the controls mechanism and response system.
Excerpted from LEED 2009 for New Construction and Major Renovations
To provide a high level of thermal comfort system control1 by individual occupants or groups in multi-occupant spacesMulti-occupant spaces are places of egress, congregation, or where occupants pursue overlapping or collaborative tasks. Multi occupant spaces may be regularly or non-regularly occupied spaces. (e.g., classrooms or conference areas) and promote their productivity, comfort and well-being.
Provide individual comfort controls for 50% (minimum) of the building occupants to enable adjustments to meet individual needs and preferences. Operable windows may be used in lieu of controls for occupants located 20 feet inside and 10 feet to either side of the operable part of a window. The areas of operable window must meet the requirements of ASHRAE Standard 62.1-2007 paragraph 5.1 Natural Ventilation (with errata but without addenda2).
Conditions for thermal comfort are described in IEQ credit 7.1: Thermal Comfort—Design and include the primary factors of air temperature, radiant temperature, air speed and humidity.
Provide comfort system controls for all shared multi-occupant spacesMulti-occupant spaces are places of egress, congregation, or where occupants pursue overlapping or collaborative tasks. Multi occupant spaces may be regularly or non-regularly occupied spaces. to enable adjustments that meet group needs and preferences.
Design the building and systems with comfort controls to allow adjustments to suit individual needs or those of groups in shared spaces. ASHRAE Standard 55-2004 (with errata but without addenda2) identifies the factors of thermal comfort and a process for developing comfort criteriaComfort criteria are specific design conditions that take into account temperature, humidity, air speed, outdoor temperature, outdoor humidity, seasonal clothing, and expected activity. (ASHRAE 552004) for building spaces that suit the needs of the occupants involved in their daily activities. Control strategies can be developed to expand on the comfort criteria and enable individuals to make adjustments to suit their needs and preferences. These strategies may involve system designs incorporating operable windows, hybrid systems integrating operable windows and mechanical systems, or mechanical systems alone. Individual adjustments may involve individual thermostat controls; local diffusersIn an HVAC context, diffusers disperse heating, cooling, or ventilation air as it enters a room, ideally preventing uncomfortable direct currents and in many cases, reducing energy costs and improving indoor air quality (IAQ). In light fixtures, diffusers filter and disperse light. at floor, desk or overhead levels, control of individual radiant panels, or other means integrated into the overall building, thermal comfort systems and energy systems design. Designers should evaluate the closely tied interactions between thermal comfort, as required by ASHRAE Standard 55-2004 (with errata but without addenda2), and acceptable indoor air quality as required by ASHRAE Standard 62.1-2007 (with errata but without addenda2), whether natural or mechanical ventilation.
FOOTNOTES1. For the purposes of this credit, comfort system control is defined as control over at least 1 of the following primary factors in the occupant’svicinity: air temperature, radiant temperature, air speed and humidity.
2. Project teams wishing to use ASHRAE approved addenda for the purposes of this credit may do so at their discretion. Addenda must be appliedconsistently across all LEED credits.
This updated version of the spreadsheet categories dozens of specific space types according to how they should be applied under various IEQ credits. This document is essential if you have questions about how various unique space types should be treated. Up to date, 2nd Edition.
This spreadsheet categories dozens of specific space types according to how they should be applied under various IEQ credits. This document is essential if you have questions about how various unique space types should be treated. This is the 1st edition.
This ASHRAE standard defines the criteria for human comfort that is followed to design mechanical systems.
This ASHRAE standard stipulates minimum outdoor air requirement and minimum window opening for naturally ventilated space. This formula is referenced in this credit where windows are used as control mechanism.
This seminal report documents the financial costs and benefits of green schools compared to conventional schools, specifically with reference to Massachusetts. Page six describes the benefits of ventilation controls on occupant productivity.
Taylor Engineering lays out design guidance for integrating operable windows into an HVAC system, while also reducing energy consumption.
In this article from ASHRAE Journal, the authors outline the benefits of an integrated designAn integrated design process (also called "integrative" design by some proponents) relies on a multidisciplinary and collaborative team approach in which members make decisions together based on a shared vision and holistic understanding of the project. Rather than a conventional linear design process in which a design is passed from one professional to another, an integrated process has all key team members talking together through out the design and construction process as they share ideas and use feedback across disciplines to iteratively move toward a high-performing design. approach for underfloor-air distribution, and explain how UFAD can contribute to LEED credits including IEQc6.2. (Subscription Required)
Operable windows are an appropriate way to meet the requirements for this credit in many building types. A single operable window can serve multiple occupants, as shown here.
A variety of sample narratives and floorplans from real projects show how different projects have achieved this credit.
Sample LEED Online forms for all rating systems and versions are available on the USGBC website.
Documentation for this credit can be part of a Design Phase submittal.
Hello, We are working on a project that is a combination of offices and food production. There are spaces dedicated to cold storage and we found as per PIF2 credit that we have to choose between regulary occupied space or unconditioned area, but we don't see if it fits in any of these descriptions. What should we do in this case?
We have a 650-bed hospital building project registered under LEED v3-Healthcare. Whole building is mechanically ventilated and conditioned. Total building users, including the FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories. staff, students, visitors, outpatients and inpatients, are estimated to be 10,191 persons daily- only 1,341 of which are the FTE staff. The building has 209 single-occupant patient rooms. As per the credit requirements, we are expected to provide 50% of the remaining 9,982 occupants with individual thermal controls. In other words, we’re asked to provide thermal controls for approximately 5,000 building occupants most of which consists of transients. Let’s say all FTE staff (1,341 users) are given individual controls. Yet, there remains 3,650 transient occupants who should be provided with individual controls. This seems practically impossible. Besides, these transients will be using multi-occupant spacesMulti-occupant spaces are places of egress, congregation, or where occupants pursue overlapping or collaborative tasks. Multi occupant spaces may be regularly or non-regularly occupied spaces. rather than individual workspaces. It seems that we can't possibly fulfill this requirement. Are there any exemptions for such cases where transients constitute the vast majority of the building users? Is there anyone who had a similar experience?
Hi Murat, good question. For the individual thermal control requirement for the remaining building occupants, I would first focus on identifying all the spaces in the project intended for individual use- such as nurse workstations,
private offices, open-plan workstations, and reception stations. Figure out how many individuals are occupying these locations and how many of those individuals have access to individual controls when they are in that location.
You can then also identify the multi-occupant spacesMulti-occupant spaces are places of egress, congregation, or where occupants pursue overlapping or collaborative tasks. Multi occupant spaces may be regularly or non-regularly occupied spaces., which as you have said will likely be used by the transient occupants.
My first question is do you have an HC or an NC project?
The next thing you need to do is get a really good handle on your occupants - who they are, how they move through the building, and how this works across each 8 hour shift. Based on your whole numbers, you've aggregated all non staff people into one number. For this credit and may others, you will need to break this down and provide a good narrative.
Break out your inpatients first. I have always counted them as 'Residents' with 0 kitchen sink use. Get a second category for infants and toddlers inpatients. They won't count in your bathroom uses. These folks are 24 hour occupants and their room controls count for them.
Next break out your outpatients. Controls for this group will work differently depending on the unit they are visiting. Don't go too far down the rabbit hole; keep looking at it from a high level.
Now separate out your visitors. To me, these are people who are here to support a patient. Some modalities will have 24 hour visitors - LDR is the first example. Pediatrics is another. Ask the nurse managers on each unit how many and how long each visitor stays. The inpatient visitor should be counted in the patient room where there are controls. The outpatient visitor will likely be staying in multi-occupant areas.
Finally, you have your transients and this is probably the hardest group to nail down. I've always looked at them as people in the hospital who aren't there to see a patient. For example, all vendors visiting the building are transients, even the architects and LEED consultants.
Why all this talk on occupancy for a controls credit? I found that by really understanding occupancy, I understand how people move within the building and this lets me determine where controls are appropriate and where they are not. I can nail down a narrative very easily. Also, occupancy is key to so many credits like the water credits. Finally, come over to the HC forum. We're a small, quiet group but some healthcare particulars are documented there.
Dear Larissa and Susan,
Thanks for your responses.
Susan, this is an HC project. I just posted this comment here thinking that I could reach more people here.
We broke down the users according to their space use as follows:
Individual workspace users: 1,341 (nurse workstations, private offices, open-plan workstations and reception desks)
Single-patient room users + 24-hour inpatient visitors: 418
Multi-occupant space users: 8,432
Total building users: 10,191
To comply with the credit requirements, we are asked to provide 4,991 occupants with individual thermal comfort controls in Table IEQc6.2-1 in the LEED Online form. Although we provide all individual users (1,759 occupants) with individual controls, we cannot show compliance in the form.
In the same credit of LEED NC v2009, it is asked to provide at least "50% of the total quantity of individual workspaces" with individual controls rather than “50% of all building users” in the LEED Online form. That’s more reasonable. However, here (in IEQc6.2 form of LEED HC v2009) it is asked to provide "50% of all building users (except for single-patient room users) with individual controls". In cases where multi-occupant space users comprise the majority of the building users, as in our case, it will not be possible to achieve the credit although the intent of the credit regarding the individual users is fulfilled (more than 50% of all individual users are provided with individual controls).
since the IEQc6.2-1 table is causing issues for your situation, I would use the special circumstances section of the LEED Online healthcare form to provide this information and explain how you are complying with the credit.
In our Healthcare project, there are different workers during the morning, afternoon and evening, with a time of 8 hours each.
If I count the FTE, I get a total of workers greater to the number of workstations. And this affects to IEQc6.1 and IEQc6.2.
What is the process for counting FTE in hospitals with 3 shifts of 8 hours per day?
How to resolve the number of workstation in IEQc6? Since the total number of workstation is linked from PIF3.
You have to select the shift with the most FTEs, do your calculations off that number and narrate the shift work and that all workstations are covered by the largest shift.
Then, I have to only specify the largest shift work in PI3 form?
So, FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories. is lower for calculations in WEp1 and others.
Then, I have to input in PI 3 Form total FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories. (all shift), and to describe the circumstances of work shifts in IEQc6.1 and IEQc6.2.
To include only the largest shift in PI 3 Form??
Our project have meeting, conference, training rooms, Canteen (Food), pantry (Coffee stations)
The meeting room have one round table with 9 occupants but table is single so we provide one ceiling fan(super fans) with control (remote with speed control)
The training room have two tables with 10 occupants each so we provide 1 fan with control for each table
The canteen have 50 tables with 12 people each so we provide two fans for single table with controls for each table
Pantry(Coffee station ) have only one table with 4 occupants and occupied once in day for 15-20 minutes and it is A/c space so it is indoor temperature, airflow is controlled with a help of controls (Indoor unit remote)
Now the doubts are
1.Is it acceptable
2.Is the multi occupants space need a single control for each table(workspace)
3. if not means what kind of controls are needed in multi occupant controls
The spaces you've described all seem to be multi-occupant spacesMulti-occupant spaces are places of egress, congregation, or where occupants pursue overlapping or collaborative tasks. Multi occupant spaces may be regularly or non-regularly occupied spaces.. Am I correct? For instance, it does not seem like they are desks for anyone. If that's the case then you just need to provide "sufficient controls to meet the needs of your users"
If some of your spaces end up functioning more like desk spaces (i.e. you have training rooms where individuals are spending all day, over many days) then you may need additional controls beyond what you've described because of their use.
Generally speaking though, coffee stations, training rooms, and meeting rooms don't have a required number of controls; it's up to you to ensure that however many you have is sufficient.
what dose consider an interview room with 2 seats in a hospital project, is it individual occupant space or shared multi occupant ?
Thanks in advance.
How do the interview rooms function? If they are close to a staff office or a patient room--in other words, if for most of the time there's just one person in the room--then I would think it's best to treat it as an individual occupant space. If it's only used for interviews between two people and empty for the rest of the day, then I would consider it a multi-occupant space like a meeting room.
I agree with Melissa!
Im not sure if we should considered an "aerobics room" a classroom and therefore as part of the multi-occupant areas to have individual control?
I would treat the aerobics room as a shared multi-occupant space with shared controls if there are no "workstations" in the room.
Our production area is sewing machines
so we install table fan with switches in every sewing table. Is it acceptable method in Individual controls
Is there any other additional controls needed for achieve this credit. Kindly explain a bit about what type of controls needed
multi occupant spaces are A/c spaces so it have single indoor unit with single remote. is it ok for Multi occupant space controls
If it is not acceptable manner means kindly tell what type of controls needed in Multi occupant spaces
The individual controls you have described seem adequate. Regarding the multi-occupant spacesMulti-occupant spaces are places of egress, congregation, or where occupants pursue overlapping or collaborative tasks. Multi occupant spaces may be regularly or non-regularly occupied spaces. - how are these spaces used? What kinds of activities occur in these spaces? Does a single indoor unit meet the needs for all of the group needs and preferences for that space?
The multi-occupant spacesMulti-occupant spaces are places of egress, congregation, or where occupants pursue overlapping or collaborative tasks. Multi occupant spaces may be regularly or non-regularly occupied spaces. are meeting, conference, Dining rooms only
The Air temperature is controlled by remote and it is fulfil the the group needs and preferences
Is it enough
What do you mean by "remote"? Do all of the occupants of the multi-occupant space have the ability to control their temperature? Assuming they do then you should be fine if you include a narrative describing some of the different uses of the spaces and then how the temperature is able to be adjusted to meet the space.
For instance, if you have a conference room space that sometimes has 10 people and sometimes has 100 people and can the occupants get the temperature just right for their space? OR, another example, is if it's the case that the conference room is partitioned off for certain meetings (how is the space adjusted in that case?)
The most important part will be your narrative and how clearly you explain how the occupants have control to meet their needs.
we have a multipurpose space that can be divided into two space depending on the necessity of the users. Does this require one or two controls?
We had the same case in a similar project. The response from the reviewers was: use the worst case scenario.
Would an operable window be an eligible type of thermal comfort control in a mechanically ventilated building or would such a control require that the building is naturally ventilated?
I recently got this credit in a mechanically ventilated building with operable windows.
Yes, it is acceptable.
We've just got back a review of a mechanically ventilated project where we claimed compliance with operable windows. According to the reviewer's comment "...the project may demonstrate compliance with this prerequisite using a combination of mechanical and natural ventilation" and that "additional guidance for this compliance strategy may be found in the LEED Reference Guide and ASHRAE 62.1-2007 Section 5."
However, as of today we have managed to comply with this credit without demonstrating compliance for natural ventilation. Has anyone ever had a similar experience?
Multifamily: For a small unit, you may only need a single control—it can be a window or a thermostat. Most units will require a control in each bedroom and in the living room or other multi-occupant spacesMulti-occupant spaces are places of egress, congregation, or where occupants pursue overlapping or collaborative tasks. Multi occupant spaces may be regularly or non-regularly occupied spaces..
What constitutes as a small unit? This project is mainly 1BRs. All units have 1 thermostat and 1 operable window. Sometimes the thermostat and operable windows are both in the living/kitchen zone and there is no direct control within the bedroom space. Is this a problem?
For residential units I find the IEQ Space Matrix to be especially helpful. According to the notes for IEQc6.2, there needs to be one thermal control located anywhere within the dwelling unit. If the unit is large enough to be split into multiple thermal zones it might make sense to add additional controls, but it is not necessarily a requirement for this LEED credit.
For credit compliance can ' Spigot damper with chord diffusersIn an HVAC context, diffusers disperse heating, cooling, or ventilation air as it enters a room, ideally preventing uncomfortable direct currents and in many cases, reducing energy costs and improving indoor air quality (IAQ). In light fixtures, diffusers filter and disperse light.' be used for the rooms that are fed by a single FCU. The below are the details of the diffuser which will allow the occupant to adjust the air speed as required using the chord.
FD Spigot Control Dampers to suit Waterloo Plenum Boxes / Neck Reducers
Designed as a cost-effective, efficient way to adjust the airflow supplied through plenum boxes or neck reducers, the FD Flap Dampers can be fitted to any of our spigots - circular, rectangular or flat oval.
They can be adjusted with a cord, fed through the air terminal device and ready for commissioning, or with an external quadrant accessible from outside the duct, allowing for the damper to be locked into position.
The other alternative is to adopt plug in device at certain workstations for the credit compliance.
Quick help will be much appreciated.
Based on your description it sounds like the product allows the user to modulate air speed and would be an acceptable thermal comfort control similar to the air diffusersIn an HVAC context, diffusers disperse heating, cooling, or ventilation air as it enters a room, ideally preventing uncomfortable direct currents and in many cases, reducing energy costs and improving indoor air quality (IAQ). In light fixtures, diffusers filter and disperse light. pictured above. However, it never hurts to submit a CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide before specifying them just to be sure.
We have a dormitory project with about 80% individual rooms and 20% double rooms. Each room is provided with a Thermostat and an operable window with over 4% operable window to floor area ratioFloor Area Ratio (FAR) is the measure of the density of non-residential land use. It is the total non-residential building floor area divided by the total buildable land area available for non-residential uses. For example, on a site with 10,000 square feet of buildable land area, an FAR of 1.0 would be 10,000 square feet of built building floor area. On the same site, an FAR of 1.5 would be 15,000 square feet of built floor area; an FAR of 2.0 would be 20,000 built square feet and an FAR of 0.5 would be 5,000 built square feet.. So, I know we can meet IEQc6.2 with the windows, but I'd like to understand if the limits on the controls would meet the credit for future projects.
The project design does not include mechanical cooling as we are in a cool northern climate with few cooling degree days. So we are not meeting ASHRAE 55-2004. There is also an allowable upper heating range on the t-stats that will be set by the BMS to conserve energy. Do these limits on the mechanical system controls meet the requirements of the credit?
LEED does not currently specify an acceptable range of temperatures needed to meet the requirements of the credit so the situation you've described with a more limited heating range would be acceptable.
I was searching the toolkit to find samples of the LEED Letter Template for this Credit bu I couldn't . Any idea where I can find it?
What will be exactly listed under?:
-Type of space
-Quantity of space ID
Hello. I have a question regarding the controllability of thermal comfort for 2 offices. We have placed 1 VAVVariable Air Volume (VAV) is an HVAC conservation feature that supplies varying quantities of conditioned (heated or cooled) air to different parts of a building according to the heating and cooling needs of those specific areas. to serve 2 offices in order to achieve 50% thermal control, however there is a restroom immediately next to one of the offices and we were thinking of providing air thru this VAV. Since the restroom does not contain any type of workstation, there shouldn't be any problem with achieving this credit when setup this way, correct?
I was wondering in order to comply with this credit, will we have to provide thermal controllability for 50% of the 7 cubicles or can we just consider it a multi-occupant space? Mind you, we have at least 44 other private offices that we are in fact meeting the 50% requirement. Its just these area that is in question. Thanks.
The requirement states that you need to meet the 50% requirement for all individual occupant spacesIn individual occupant spaces, occupants perform distinct tasks from one another. Such spaces may be contained within multi-occupant spaces and should be treated separately where possible. Individual occupant spaces may be regularly or non-regularly occupied spaces. so you could add the cubicles to the private offices and ensure that (in total) you are meeting the 50% requirement. It sounds like you are.
However, to specifically address your question about the medical records spaces I would say that the cubicles you've described do sound like workstations. Have you seen the Space Matrix? In it, for health care, the USGBC allows medical records to be excluded spaces so it's possible you could make a case for excluding those spaces. I think it would all be in how you defined those spaces.
I've got the following note during my preliminary design review: "2. Several spaces have not been included on the form (....). The HVAC plans provided do not show controls in all of these spaces. Revise the form to include these spaces as either individual workspaces or shared multi-occupant spacesMulti-occupant spaces are places of egress, congregation, or where occupants pursue overlapping or collaborative tasks. Multi occupant spaces may be regularly or non-regularly occupied spaces., and provide HVAC plans highlighting the controls provided in these spaces.".
My question is; can I demonstrate the missing controls on "FURNITURE DRAWING", on a drawings set entitled "FURNITURE AND CONTROLS DRAWINGS SET" for my final review submittal, or I must submit "HVAC" drawings, as stated?
Yes, you can demonstrate the missing controls on your furniture and controls drawing set.
Hallo, in our project there is a space that can be used as either open office or meeting room because the furniture will allow that flexibility. Should I consider it as a multi-occupied space or as individual workstations (open office).
either designation is acceptable as long as you justify your decision.
We have a shipping room in our office NC building. The room has 11 lockers, each locker has a chair for 1 occupant. The 11 occupants of this room are supposed to stay for 15 minutes at the beginning of each day to check the lockers, and for another 15 minutes at the end of the day.
I need to know the best approach for documenting this room, whether to consider this space as:
1. Multi-occupant space (need 1 control unit)
2. Open Work-space (need 11 control units)
3. Non-occupied space (Doesn't need control)
It would be Multi-occupant based on your description so make sure you describe how the controls you've set up meet the various needs of the occupants.
We have a project that has a large number of individual work stations and we are trying to achieve this credit by providing underfloor air diffusersIn an HVAC context, diffusers disperse heating, cooling, or ventilation air as it enters a room, ideally preventing uncomfortable direct currents and in many cases, reducing energy costs and improving indoor air quality (IAQ). In light fixtures, diffusers filter and disperse light. for each work station. Is there any rule regarding how close the diffuser has to be from the work station? Has anyone had any experience with this?
Nope - you just need to add up the number of work stations in the room vs the number of operable diffusersIn an HVAC context, diffusers disperse heating, cooling, or ventilation air as it enters a room, ideally preventing uncomfortable direct currents and in many cases, reducing energy costs and improving indoor air quality (IAQ). In light fixtures, diffusers filter and disperse light..
For an office space with 100 individual working spaces the project team has used operable windows in order to provide thermal comfort control. 80 working spaces are located within 20 feet of a window to the inside, and ten feet from side to side. However, we have got a response from the reviewer that “it is unclear that this space has 80 individual operable windows.” From our understanding operable windows are not supposed to be individual, which cannot occur by definition in an open-plan office space. Is that correct?
That's a rough comment. The credit says you need to be close to an operable window OR have individual control. I'd recommend you appeal the decision if you're rejected.
I agree with Dylan, the review comment is incorrect.
Charalampos, was your approch accepted by GBCIThe Green Building Certification Institute (GBCI) manages Leadership in Energy and Environmental Design (LEED) building certification and professional accreditation processes. It was established in 2008 with support from the U.S. Green Building Council (USGBC). or did they say in the end that there has to be one operable window per person in order to comply with the credit requirements?
Agata, just to clarify that this project was seeking the corresponding credit of v4. However, although the reviewer's technical advice is not part of the "changes from LEED 2009" section of v4 reference guide we had to comply with it and provide alternative means of the thermal comforts such as desktop fans.
Do you know if it's still possible to achieve this credit in v2009 by using operable windows (one window would be for more than one person or two)? People without access to windows could use fancoil units.
So far yes, we have managed to achieve this credit at v3 projects with one operable window for more than one occupants as long as those occupants are within 20 feet of this window to the inside, and 10 feet from side to side.
Thank you for a quick response!
Hi Charalampos, the requirement for operable windows has not changed for LEED v4. I will discuss this with GBCIThe Green Building Certification Institute (GBCI) manages Leadership in Energy and Environmental Design (LEED) building certification and professional accreditation processes. It was established in 2008 with support from the U.S. Green Building Council (USGBC). to make sure it is being interpreted properly for LEED v4, and we will consider releasing an addendum to the reference guide to further clarify.
Thanks Larissa! That would be very helpful!
Hi Larissa, we've just received a review for a v2009 project and the reviewer has commented that "it appears that each operable window has been counted as a thermal control for multiple occupants located close to the windows and that this credit only allows an operable window to be utilized as a single thermal control (e.g. each operable window could only be applied to one workstation or shared multi occupant space)." Obviously so far we have been able to comply with the credit requirements providing operable windows which are not individually operable.
Did you have the chance to discuss this issue with the GBCIThe Green Building Certification Institute (GBCI) manages Leadership in Energy and Environmental Design (LEED) building certification and professional accreditation processes. It was established in 2008 with support from the U.S. Green Building Council (USGBC).? Thank you.
Hi Charalampos, Yes I have talked with GBCIThe Green Building Certification Institute (GBCI) manages Leadership in Energy and Environmental Design (LEED) building certification and professional accreditation processes. It was established in 2008 with support from the U.S. Green Building Council (USGBC). about this issue for LEED 2009 and LEED v4. They will be clarifying the requirements to the reviewers but there may be a few projects already in the pipeline that will be impacted as your project apparently has. Thanks!
Initial design review has just been returned for our project. In the review comment, example of accessibble individual controls are defined as hand-held remote controls or wall-mounted controls located no higher than 48 inches AFF. Our project has wall-mounted controls located higher than 48 inch. Does anyone know whether the location of switch is mandatory to meet this credit? Is it mere recommendation? Any comment would appreciated. Thank you.
There are no specific height requirements for the location of the switch- as long as the occupants can access the control it is acceptable.
There may be code implications. Always something to look at. ADA may not allow them to be that high.
What can be considered as a Radiant Temperature control? Do blinds or curtains count if occupant is within 20 feet from the window?
No. Radiant temperature control would be a thermostat that controls flow to a radiant ceiling or floor zone.
This project is based in highly humid place, we have used dew point control logic for AHU1.Air-handling units (AHUs) are mechanical indirect heating, ventilating, or air-conditioning systems in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and conveyed to and from the rooms by a fan and a system of distributing ducts. (NEEB, 1997 edition)
2.A type of heating and/or cooling distribution equipment that channels warm or cool air to different parts of a building. This process of channeling the conditioned air often involves drawing air over heating or cooling coils and forcing it from a central location through ducts or air-handling units. Air-handling units are hidden in the walls or ceilings, where they use steam or hot water to heat, or chilled water to cool the air inside the ductwork. control.
In this control logic, we are controlling 2-way chilled water valve from signal from supply air dew point. VFDA variable frequency drive (VFD) is a device for for controlling the speed of a motor by controlling the frequency of the electrical power supplied to it. VFDs may be used to improve the efficiency of mechanical systems as well as comfort, because they use only as much power as needed, and can be adjusted continuously. is controlled from return air temperature signal.
Set point of supply air dew point is kept at 50F, so that humidity levels in room shall be taken care of during peak latent load condition also. Variations in sensible load are handled by VFD modulation.
We wanted to check with experts from LEED point of view that can we avoid RH sensors ? As you will see from above control logic, we are achieving humidity control through supply air dryness and RH sensor is not playing any controlling role.
This LEED credit wouldn't help to answer your question in terms of if you can avoid RH sensors. The key question to ask is if you are providing controls that are helping occupants change one of the key thermal comfort metrics noted above. It's not clear to me from your description whether or not this is the case. You only need to control one of the following:
- air temperature
- radiant temperature
- air speed.
The question seems more applicable to a different credit - IEQc7.1 Thermal Comfort Design. For IEQc7.1, I believe your method would qualify as acceptable humidity control without having RH room sensors.
Thanks Lauren and Julia for your response.
So to qualify for IEQc 6.2, I have to have individual control for any of the our comfort key parameters to 50% of the occupants?? Though this design approach is acceptable for IEQc7.1 as highlighted by Julia.
Thanks in advance,
I work on a CS project ventilated by AHUs and approach both IEQp1/IEQc2 and IEQc6. For getting the IEc6 points both room controllers and operable windows are used. I was given a comment from the USGBC saying I should indicate in the IEQc6 form also "project building is naturally ventilated". This is linked to IEQp1 and IEQc2 form which means an additional table IEQp1-A5 must be fulfilled. The buiding is ventilated mechanically by AHUs and these operable windows can be used only to improve comfort controlability in lieu of room controllers. Therefore presenting calculations confirming proper operation of natural ventilationin the IEQp1-A5 is pointless. I haven't met in the Reference Guide suggestions to rearrange the ventilation priciple in the case of using operable windows for IEQc6.
Thank you in advance
Hi- I also am not aware of the operable windows in IEQ6.2 requiring natural ventilation under IEQp1. However, because the reference guide requires that the operable window area must be at least 4% of the floor area to be influenced in IEQ6.2, it amounts to the same thing. Essentially, you need to prove that the area served by the operable window would qualify per the natural ventilation criteria.
In this case, it is probably best to comply with the reviewer's comment rather than complaining about technicalities. Note that you do not need enough operable window area to ventilate the entire room. You only need to provide the natural ventilation "equivalent" to serve the area you claim will receive the comfort benefit of the operable window.
We are consultants for a mall seeking LEED. Most of the spaces will be tenanted. The owner will be installing the main HVAC system (Chillers & Boilers), whereas the tenants will fit out their HVAC system later.
I am trying to assess the difficulty in achieving this credit. The mall will contain retail shops, restaurants, and movie theaters (all are tenanted). The C&S areas fitted by the owner are basically the underground parking levels and the mall circulation areas (mall concourse).
My queries below:
1) Generally speaking, is it too difficult to achieve this credit?
2) The mall concourse circulation is occupied by transient occupants. It would not make sense to provide these transients with thermal comfort controls. However, the circulation area has a thermostat which is controlled by the Mall's facility managers if need be. Is this sufficient for complying with this credit?
3) Restaurants & Retail shops will have FTEFull-time equivalent (FTE) represents a regular building occupant who spends 8 hours a day (40 hours a week) in the project building. Part-time or overtime occupants have FTE values based on their hours per day divided by 8 (or hours per week divided by 40). Transient Occupants can be reported as either daily totals or as part of the FTE. Residential occupancy should be estimated based on the number and size of units. Core and Shell projects should refer to the default occupancy table in the Reference Guide appendix. All occupant assumptions must be consistent across all credits in all categories. employees and transient visitors. Is it sufficient to have 1 thermostat control for each restaurant / retail, and this thermostat operated by the shop's employees (not transients)? If a retail shop has 3 employees, it doesn't make sense to provide 3 controls, as the employees will be constantly moving in the shop (unlike a shared office space whereby each person works on 1 fixed desk).
PS: I posted this under LEED C&S forum a week ago but didn't get any response - I feel that the NC forum is always in action!
Note that core and shell projects must purchase or install the mechanical system or operable windows (or a combination of both) in order to achieve the intent of this credit. The distribution ductwork does not have to be completed, however.
1) If you only have one single-zone unit per shop or restaurant, it is probably too difficult to achieve this credit.
2) Some projects have included a narrative stating that staff will be available to adjust the locally accessible room thermostat if requested by transient occupants. Alternately, the public could have access to a very narrow range of set point adjustment that is automatically reset at the start of each day.
3) I believe a restaurant kitchen would need its own thermostat. The counter area might also need a separate control from the kitchen and dining area, depending on the arrangement. While one thermostat for a multi-occupant retail floor should be sufficient, you would also have to provide separate control for any potential back-of house areas such as a manager's office or a staff break room.
Step-by-step instructions for filling out the LEED Online credit form.
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