REPORT TO COUNCIL
SUBJECT
Title
Adopt a Resolution to Update the Green Building Program for Residential Projects, Non-Residential Projects and Public Facilities
Report
REPORT IN BRIEF
As part of the City's 2009 green building program, staff was directed to return to Council approximately every 18 months to review the green building tables for possible implementation of three separate phases. This is the third phase of the program. The intent of each phase is to evaluate how the program is working and determine if the standards should be increased.
After almost four years of experience, the green building program is working well overall. Particularly important is that the program uses standardized green building checklists (LEED and GreenPoint Rated), which are commonly used throughout the Bay Area and nationally. Over the past several years the popularity and availability of green construction products and techniques has increased greatly. Therefore, staff is recommending adoption of the resolution in Attachment 1 which updates the green building program as follows:
Residential Projects:
• Raise the Build It Green point level for new construction to 110 points as the minimum and 150 points for the incentives;
• Modify the requirement for remodels, alterations, and additions to require the CalGreen mandatory measures for all projects, regardless of the project construction valuation.
Non-Residential Projects:
• Maintain the LEED Silver level for new construction between 5,000 and 25,000 square feet and LEED Gold for incentives.
• Increase the LEED level to Gold for new construction greater than 25,000 square feet and LEED Platinum for the incentives.
• Increase the standard for major alterations to require projects between 5,000 square feet and 25,000 square feet meet a LEED Certified Level and projects greater than 25,000 square feet meet LEED Silver.
• Allow up to an additional 10% FAR in the Moffett Park area through approval of a Major Moffett Park Special Development Permit. Project must show green development features, transportation demand management or other sustainability measures significantly beyond those required to obtain the 15% or 20% density incentive.
Public Facilities:
• Maintain the current standards for new construction, which requires LEED Gold for new buildings greater than 5,000 square feet (unless determined infeasible).
• Increase the standard for a major alteration to match that of the non-residential projects.
All proposed changes would be effective for all projects that submit building permit applications on or after November 1, 2014.
The Sustainability Commission discussed this item at its March 17, 2014 meeting. The Sustainability Commission was in agreement with the above recommendation and voted 5-0 to adopt standards at least as rigorous as above. The Sustainability Commission also moved to consider requiring conduit to be installed in all new residential buildings for future photovoltaic systems. Staff has not included this in the recommendation.
The Planning Commission discussed this item at its April 14, 2014 meeting. At the meeting staff provided an updated recommendation related to the Moffett Park Specific Plan (MPSP) Area, which is reflected in the recommendation at the end of this report (Alternative 1). The Planning Commission voted 5-2 to recommend that the Council adopt the revised staff recommendation.
BACKGROUND
The first City-wide green building program was implemented in 2004 and included public awareness policies and incentives for non-residential development. That same year green building requirements specific to Moffett Park were included as part of the MPSP. The MPSP incentivizes the development of Class A office buildings through a streamlined review process subject to the provision of green buildings. The MPSP acknowledges that the LEED standard may need to be changed over time to achieve the city's vision of a more sustainable and energy efficient community.
In March 2009, the City Council approved a city-wide green building program that became effective January 1, 2010. This included minimum green standards for all new construction and major alterations/additions. The adopted ordinance set up a framework for residential and non-residential projects that could be modified over time to require higher levels of "green" achievement. The program was designed in three phases, with each phase increasing the level of green building required. The first phase was effective January 2010, the second phase was fully effective in October 2012 (the non-residential requirements were implemented earlier in October 2011). This will be the third phase of the program.
The green building program uses three green building codes/standards and requires various types of construction to meet specified levels. Following is a summary of each code/standard.
CalGreen
First effective on January 1, 2011, CalGreen is the California Green Building Standards Code. CalGreen is developed by the State of California and is a part of the building codes. This code sets standards for green construction in California. Initially CalGreen was limited to new construction. However, the current version requires additions and many non-residential alterations to existing buildings to meet CalGreen requirements for the area under construction.
CalGreen includes mandatory standards as well as optional Tier 1 and Tier 2 standards. The mandatory requirements are minimum standards that are applicable to all covered projects. The Tier 1 and Tier 2 standards are optional levels of higher green standards that can be adopted by local jurisdictions. However, even the highest CalGreen Tier 2 level represents a lower standard than the GreenPoint Rated and LEED levels proposed below.
Build It Green
Build It Green is an independent non-profit organization committed to promoting green building. They have developed the GreenPoint Rated Checklist, which is a point based system providing options for a variety of green building techniques, allowing project designers and owners to select the items that are applicable or desirable for a specific project. The rating system is divided into categories for energy, indoor air quality, resource conservation, water conservation, and community connectivity, with a minimum number of points required in each category.
LEED
LEED, or Leadership in Energy and Environmental Design, is a rating system developed by the United States Green Building Council (USGBC) that provides credits for green building features and assigns a LEED level (Certified, Silver, Gold, or Platinum) based on the number of credits achieved. Similar to the GreenPoint Rated Checklist, the LEED rating system includes categories for Location and Transportation, Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, Innovation, and Regional Priorities.
EXISTING POLICY
Community Vision Statement
A regional leader in environmental sustainability:
advocating to reduce dependence on non-renewable resources by providing greater transportation options, reducing waste, protecting our natural resources, and promoting alternative energy usage and research. We take environmental preservation and protection seriously and consider how each action will affect Sunnyvale for future generations.
Community Vision Goal III.
Environmental Sustainability: To promote environmental sustainability and remediation in the planning and development of the City, in the design and operation of public and private buildings, in the transportation system, in the use of potable water and in the recycling of waste.
Green Building Requirements (Title 19)
19.39.030
(h) The city council shall establish by resolution, and shall periodically review and update as necessary, green building standards for compliance. The standards for compliance shall include, but are not limited to, the following:
(1) The types of projects subject to regulation (covered projects);
(2) The green building rating system to be applied to the various types of projects;
(3) Minimum thresholds of compliance for various types of projects; and
(4) Timing and methods of verification of compliance with these regulations.
ENVIRONMENTAL REVIEW
A Negative Declaration was prepared for the 2009 green building ordinance and program, and the proposed changes do not substantially exceed or create any negative impacts not already contemplated and studied in that negative declaration. Therefore, no additional environmental analysis is required to be performed to update the Green Building Tables.
DISCUSSION
Current Green Building Program
The current green building tables (Attachment 2) include graduated requirements based on the scope of projects. These tables require some level of green building for many projects, though there are small projects that do not have a green building requirement (such as re-roofing projects, small residential additions, and minor tenant improvements). This approach has been used to educate the public about green measures and to influence their development decisions. The minimum required green effort increases with larger projects and includes voluntary incentives for higher levels of green building.
The 2013 CalGreen was effective on January 1, 2014. This code version greatly increased the type of projects that are covered by the CalGreen standards. When first applicable in January of 2011, CalGreen only applied to new construction. Various modifications were made over the past few years and now the CalGreen applies to all residential additions, non-residential additions/alterations with a permit valuation of greater than $200,000 as well as all new construction.
Staff has taken several actions to assist design professionals and homeowners in achieving the green building program requirements as well as the CalGreen requirements including the following:
· A website with information and links to resources at:
· Informational brochures and FAQs on the green building program; and
· Prescriptive checklists that provide applicants with pre-selected items that, if used, will ensure compliance with the green building requirements.
The structure of the current program has been well received by the development community and property owners. Staff has received positive feedback that the program requirements are clearly described and that the use of standardized green building checklists (LEED and GreenPoint Rated) is helpful as most design professionals are familiar with them.
Comparison of Requirements to Other Jurisdictions
As part of this phase of implementation, staff researched the green building requirements in other local jurisdictions. The summary is provided in Attachment 3. Many local jurisdictions rely only on the CalGreen code mandatory measures and have not adopted higher standards. Although some jurisdictions may have higher requirements for a specific project type and size, the overall program requirements in Sunnyvale's green building program is still a leader in the Bay Area.
Residential Projects
Minimum Standards for New Residential Construction
The minimum point level to achieve certification through the Build It Green organization is 50 points. Sunnyvale's program currently requires a minimum of 80 points so that we provide a green building standard above the minimum. Based on programs in other local jurisdictions, 80 points is still at the high end. Almost half of the jurisdictions surveyed did not have any green building requirements beyond the State mandated CalGreen.
While working with design professionals and homeowners, staff has found that the awareness and understanding of green building requirements has increased significantly. The GreenPoint Rated Checklist is commonly used throughout the Bay Area, allowing design professionals to apply their knowledge and experience from projects across different geographical areas to projects in Sunnyvale.
Staff recommends continued use of the generally accepted GreenPoint Rated Checklist for residential construction. With the objective of Sunnyvale maintaining a leadership role in promoting green building construction, staff recommends increasing the minimum GreenPoint Rated requirement from the current 80 points to 110 points for all new construction. This point level would be higher than the minimum required from Build It Green and would be the highest standards among local jurisdictions surveyed. Staff also recommends increasing the points required for the incentives to 150 (from 110). Based on current trends in green building construction, staff believes the higher point requirement will challenge residential builders but is still an achievable level.
Minimum Standards for Residential Alterations
Alterations to existing buildings include a wide range of projects from replacing a sewer line to a large addition. Many of the smaller projects do not affect enough change in an existing building to achieve a minimum green building point level. Therefore, the alteration projects are separated into the following threshold categories based on improvement value:
· Single-family/duplex - up to $100,000 and over $100,000
· Multi-family - up to $250,000 and over $250,000
Currently, the higher level category for each type of residential building requires that the project meet the CalGreen requirements that are applicable to the scope of work. However, with the adoption of the 2013 CalGreen, that code applies to residential additions, as well as new construction.
Staff recommends strengthening the requirement for all alterations to include the CalGreen items that are applicable to the scope of the alteration (the CalGreen code only applies to new residential construction or additions). For example, if the alteration included remodeling the bathroom, in addition to the standard energy efficiency upgrades required by the California Energy Efficiency Regulations, the project would also need to meet the CalGreen requirements for low VOC adhesives and paints.
Requirements for Verification of Residential Green Building Items
An important factor in assuring the green building thresholds are met is the verification that these items are included in the construction documents and are installed properly. Currently, the standard requirement is that these items are verified by a GreenPoint Rater, but the project is not required to be submitted to the Build It Green organization for verification. If an incentive is used, the current program requires the project to be submitted to the Build It Green organization for certification.
Staff has received feedback that the certification process through the Build It Green organization can be expensive and time-consuming. Also, the official certification comes several months after the construction is complete and the building is occupied. The goal of the green building program is to achieve high levels of green construction, but without increasing unnecessary costs. Staff recommends maintaining the current practice that all GreenPoint Rated Checklists be verified by a GreenPoint Rater, and not requiring submittal for formal certification.
Residential Incentives
The green building program provides incentives for new residential construction to encourage a higher "green" level for obtaining 110 Build It Green points (rather than the current standard of 80 points). The incentives include an option for additional lot coverage, building height, or density.
One residential project under construction has taken advantage of the green building incentive. The Carmel Partners projects at the former Town and Country site adjacent to Plaza del Sol (approved in October 2011) will achieve a minimum of 110 GreenPoint Rated Checklist points and was approved with a 5% density bonus. Several other projects that are currently in the entitlement review or building permit review phases are planning to use the incentive for the density bonus (e.g. Iron Work which is two approved developments on E. Evelyn Avenue being developed by Prometheus Real Estate Group and two pending E Weddell projects proposed by Raintree Partners and Sares-Regis Group). Staff has received inquiries regarding the use of the green building incentive for other projects that are in the pre-application phase.
Non-Residential Projects
Minimum Standards for New Non-Residential Construction
The minimum LEED level is Certified followed by Silver then Gold then Platinum as the highest level. The current green building program requires non-residential projects larger than 5,000 square feet to meet a LEED Silver level.
Staff recommends increasing the minimum LEED requirement for new non-residential buildings greater than 25,000 square feet to LEED Gold as the standard. The LEED Silver level would remain for new buildings between 5,000 square feet and 25,000 square feet. Buildings less than 5,000 square feet would maintain the current CalGreen requirement. Staff recommends maintaining the current level for buildings less than 25,000 square feet as higher LEED levels may be dis-proportionally more expensive for smaller sized buildings.
Minimum Standards for Non-Residential Alterations
Non-residential building alterations vary widely in scope and square footage of affected area. Therefore, the current standards for the non-residential alterations are applicable to projects that affect a significant portion of the building (structural, mechanical, plumbing, and electrical alterations) and contain the following square footage threshold:
· 5,000 to 50,000 square feet - LEED Checklist, no minimum points required
· Greater than 50,000 square feet - LEED Checklist with Certified Level
The 2013 CalGreen also requires non-residential alterations with a project valuation greater than $200,000 to meet the CalGreen items that are applicable to the scope of work.
Staff recommends the requirement for all alterations be strengthened as follows:
· 5,000 to 50,000 square feet - LEED Checklist with Certified Level
· Greater than 50,000 square feet - LEED Checklist with Silver Level
CalGreen items would still be applicable to projects based on the valuation, but the LEED standards are generally higher and would result in a "greener" project.
Requirements for Verification of Non-Residential Green Building Items
As with the residential projects, certification of the LEED checklist through the USGBC is currently required for projects that use an incentive. Other projects are verified by a LEED Accredited Professional (LEED AP). Staff has received positive feedback on the current LEED AP verification process, as the process to certify through the USGBC is expensive and time-consuming. Also similar to the residential projects, staff recommends maintaining the existing practice that all LEED levels be verified by a LEED AP and not requiring certification through the USGBC.
Non-Residential Incentives
The green building program provides incentives for new non-residential construction to encourage a higher level of green construction. The higher LEED levels allow a project to increase the FAR allowed.
Several office projects have been approved with the green building incentive and more are in the entitlement review phase. This incentive has proven to be popular among office developers. Currently, there is a very high demand for new office buildings within the City. Due to this high demand, the City's development reserve (within the MPSP area) and development pool (over the rest of the City) are being reduced. Therefore, staff is recommending a significant increase in the non-residential incentive level for buildings greater than 25,000 square feet. Staff recommends the incentive for these buildings be increased to LEED Platinum, the highest LEED level, while maintaining LEED Gold as the incentive for buildings between 5,000 square feet and 25,000 square feet.
The increased FAR allowed in the MPSP is 15% in the MP-I zoning district and 20% in the MP-TOD. As noted above, staff recommends that a project meet the LEED Platinum level to receive these FAR incentives. In order for a project in the MPSP area to also qualify for the City-Wide 10% FAR increase, staff recommends allowing it to be considered through approval of a Major Moffett Park Special Development Permit. Also, the project must show green development features, transportation demand management, or other sustainability measures significantly beyond those required to obtain the 15% or 20% density incentive.
Public Facilities
The current requirements for Public Facilities are included in Attachment 2.
The principle for public facility requirements has been that these should exceed the requirements for private developments, as the City should set an example of the importance of green building. Even with the staff recommended updates to the non-residential requirements, the current standards for new construction of public facilities are higher than that for private developments.
The current standards for major alterations of public facilities are higher than private developments, but the recommended modifications of private development will be higher. Therefore, staff is recommending that private facilities meet the same requirements for major alterations as recommend for private as follows:
· 5,000 to 50,000 square feet - LEED Checklist with Certified Level
· Greater than 50,000 square feet - LEED Checklist with Silver Level
Staff believes it will be difficult for major alterations of public facilities to exceed these requirements because City facilities can range greatly in scope (i.e. park buildings, fire stations, water treatment facilities, Community Center Theater, etc.) and do not necessarily meet the typical office/commercial characteristics.
Implementation of Updated Requirements
Staff has continuously heard from the development community that green building has the least cost impact when it is considered at the earliest design stage of a project, including when preparing the preliminary site plan. A minimum six-month grace period after adoption of new building requirements typically provides adequate time for customers that are currently preparing construction plans to complete their plans and submit them before the changes are effective. The recommended effective date for the updated green building tables is January 1, 2015. Building permit plans submitted before this date would be subject to the current standards, while building permit plans submitted after this date would be subject to the updated standards.
Since the Planning Commission meeting, several property owners/developers with approved projects (i.e., planning entitlements already granted) have expressed concerns about the economic hardship that would be imposed if building plans could not be submitted before the effective date. They did not anticipate a significant increase in the City's green building standards when their projects were submitted for planning approval. Large phased projects that were intended to be constructed over multiple years would most likely be affected. Building permit plans for later buildings may not be submitted until well after the effective date of the proposed changes; the unbuilt portion of the project would be subject to different standards. For example, a developer that received a higher FAR through the green building incentive is currently required to have their buildings certified LEED Gold. If building plans are submitted after the effective date, the minimum standard increases to LEED Platinum and, where applicable, additional sustainability measures might be required. Developers that have preliminarily designed their buildings would incur additional cost to revise their building plans and the cost of constructing those buildings could be greater under the new standards.
Instead of setting building plan submittal as the basis for the effective date of the updated green building tables, the Council could choose to "grandfather" in projects that have received planning approvals prior to the effective date. Only projects that received planning approvals after January 1, 2015 (or another date) would be subject to the updated green building tables. If this option is selected, the Council may choose to stipulate that projects with prior planning approvals must submit building permit plans by a certain time period, such as within three years of the effective date, or the updated standards would apply.
Sustainability Commission Meeting
This item was included on the Sustainability Commission meeting of March 17, 2014 for discussion. The Commission was in support of raising the standards to those recommended in this report. Several items were discussed, including how this relates to the Climate Action Plan (CAP), how CalGreen and GreenPoint Rated/LEED compare, and the possibility of requiring photovoltaic ready items for new residential construction.
In order to achieve the greenhouse gas (GHG) emission reductions levels of Assembly Bill 32 and Senate Bill 375, a CAP is scheduled to be considered by the Council in May. The CAP provides a framework of options the Council could adopt that would reduce GHG emissions. The various options will then be weighed based on various factors such as cost, impact on the community, and amount of GHG reduction achieve. While some of these options will affect construction, staff believes the CAP items should be evaluated as a package and decisions made on how best to achieve the GHG goals, rather than as part of the scheduled update to the existing green building program.
As discussed in the Background section above, the proposed GreenPoint Rated and LEED levels are a higher green standard than the highest CalGreen level of Tier 2. Therefore, staff recommends continuing with the GreenPoint Rated and LEED programs.
The Sustainability Commission also requested that staff consider the possibility of requiring new residential construction to be photovoltaic ready by installing conduit from the electrical panel to the roof to allow for future photovoltaic wiring. The intent of this is to allow easier installation of photovoltaic panels should a homeowner choose to install them in the future.
On July 1, 2014, a new version of the California Energy Efficiency Standards (CEES) will be effective. These standards will include a requirement that all new residential developments of 10 or more units include a minimum of 250 square feet of clear area (free of plumbing vents and roof vents) on the roof to allow for photovoltaic panels to be installed.
Staff believes that the CEES requirement reduces the barriers to future photovoltaic installation by ensuring that adequate roof area is provided to locate future panels. Staff does not recommend an additional requirement for conduit to be installed as this has not been a barrier to photovoltaic panel installations in existing houses. The conduit installation is one of the easier parts of the installation and needs to be sized and located based on the size and design of the photovoltaic panels. So, if conduit were to be pre-installed in new construction, it may or may not be effective for a future photovoltaic system.
Planning Commission Meeting
At the Planning Commission meeting on April 14, 2014, staff provided an updated recommendation related to the MPSP Area, which is reflected in the staff recommendation at the end of this report (Alternative 1).
The Planning Commissioners asked questions about the LEED program, congregated solar, and community benefits achieved through green building. A question was also asked about the possibility of requiring new construction to be dual plumbed for reclaimed water. Dual plumbing was the subject of a Study Issue in 2010 (RTC 10-250) and is included in the Feasibility Study for Recycled Water Expansion (RTC 13-181). The adopted Feasibility Study did not recommend requiring dual plumbing within new buildings (to allow certain plumbing fixtures to use recycled water) due to the limited water savings and lower cost alternatives. However, the Feasibility Study did recommend requiring using recycled water for landscape irrigation due to the high potential for water-savings. Staff has been requiring new buildings to use recycled water for landscape irrigation when it is available at the site.
Two members of the public spoke. One person asking for the item to be continued and the other expressing concern over the cost of the recommended LEED level, stating that 35% FAR is very low, and asking that no action is taken to increase the green building requirements.
The Planning Commission voted 5-2 to recommend that the Council approve the modified staff recommendation.
Council Policy 1.1.9 Sustainable Development and Green Building Update
In 2004, Council adopted Policy 1.1.9 Sustainable Development and Green Building Update to encourage sustainable development throughout the City. This was part of the first green building study that included public awareness policies and incentives for new non-residential construction. Since this policy was adopted, the green building program has been developed and includes minimum green building standards for new construction and remodels. Staff recommends updating this policy to reference the green building program for minimum public facility, residential, and non-residential construction (Alternative 2).
FISCAL IMPACT
The staff recommended changes to the green building program would not have a fiscal impact. If further modifications are made to the green building program, there may be a fiscal impact to the Building Division as additional plan review and inspection resources may be needed if significant new requirements are implemented.
PUBLIC CONTACT
Public contact was made through posting of the Planning Commission agenda on the City's official-notice bulletin board, on the City's website, and the availability of the agenda and report in the Office of the City Clerk.
Notices were sent to the neighborhood associations, developers and design professionals involved in development in Sunnyvale, and posted at the One-Stop Permit Center.
This item was also on the March 17, 2014 Sustainability Commission meeting agenda for discussion and on the April 14, 2014 Planning Commission agenda
ALTERNATIVES
1. Adopt the Resolution to Update the Green Building Tables for Residential Buildings, Non-Residential Projects, and Public Facilities (Attachment 1) which includes the following:
Residential Projects:
· Raise the Build It Green point level for new construction to 110 points as the minimum and 150 points for the incentives;
· Modify the requirement for remodels, alterations, and additions to require the CalGreen mandatory measures for all projects, regardless of the project construction valuation.
Non-Residential Projects and Public Facilities:
· Maintain the LEED Silver level for new construction between 5,000 and 25,000 square feet and LEED Gold for incentives.
· Increase the LEED Level to Gold for new construction greater than 25,000 square feet and LEED Platinum for the incentives.
· Increase the standard for major alternations so that projects between 5,000 square feet and 25,000 square feet meet a LEED Certified Level and projects greater than 25,000 square feet meet LEED Silver.
· Allow up to an additional 10% FAR in the Moffett Park area through approval of a Major Moffett Park Special Development Permit. Project must show green development features, transportation demand management or other sustainability measures significantly beyond those required to obtain the 15% or 20% density incentive.
Public Facilities:
· Maintain the current standards for new construction, which requires LEED Gold for new buildings greater than 5,000 square feet (unless determined infeasible).
· Increase the standard for major alteration to match that of the non-residential projects.
2. Adopt the revised Council Policy 1.1.9 Sustainable Development and Green Building (Attachment 6).
3. Adopt the Resolution in Attachment 1 to Update the Green Building Tables for Residential Buildings, Non-Residential Projects, and Public Facilities with modifications.
4. Take no action and maintain the current green building standards.
STAFF RECOMMENDATION
Recommendation
Alternatives 1 and 2: 1) Adopt the Resolution to Update the Green Building Tables for Residential Buildings, Non-Residential Projects, and Public Facilities (Attachment 1); and 2) Adopt the revised Council Policy 1.1.9 Sustainable Development and Green Building (Attachment 6).
The staff recommendation considers the Council's adopted policy to have the City be a leader in green building and sustainability, ease of use of the program, and minimum impact on express plan reviews at the One-Stop Permit Center. In order to be a leader and maintain ease of use of the program, staff is recommending continued use of the standardized programs (GreenPoint Rated and LEED), but require a higher level than most other jurisdictions. This approach provides some level of consistency for design professionals in that they can familiarize themselves with these programs. While a higher point level may be the standard in Sunnyvale, it is based on the same overall programs.
Under Alternative 1, the effective date of the undated Green Building Tables would be January 1, 2015; building permit plans submitted after this date would be subject to the updated standards. Alternatively, if the Council believes that the updated standards should only apply to projects that receive planning approvals after the effective date (i.e., projects with planning approvals before the effective date would comply with current standards), then Alternative 3 should be adopted with a modification to the resolution.
Staff
Prepared by: Diana Perkins, Permit Center Coordinator
Reviewed by: Trudi Ryan, Planning Officer
Reviewed by: Hanson Hom, Director, Community Development
Approved by: Robert A. Walker, Interim City Manager
Attachments
ATTACHMENTS
1. Draft Resolution to Update the Green Building Tables
2. Current Green Building Program Requirements
3. Green Building Requirements from Other Local Jurisdictions
4. Sustainability Commission minutes from March 17, 2014
5. Planning Commission draft minutes from April 14, 2014
6. Revised Council Policy 1.1.9 Sustainable Development and Green Building