Green Roofs Planning-Low Zero Impact Buildings

Implementing Extensive GREEN ROOF on New Educational building in the UK to achieve BREEAM standard.

Low Zero Impact Buildings-UBLMQ4-15-M

Student Number: 21039883 Word Count:2568

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Introduction------------------------------------------------------------------------------------Why?---------------------------------------------------------------------------------------------What?--------------------------------------------------------------------------------------------How?---------------------------------------------------------------------------------------------When?-------------------------------------------------------------------------------------------Who?---------------------------------------------------------------------------------------------Conclusion---------------------------------------------------------------------------------------

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IMAGES Image 1: Image 2: Image 3: Image 4:

Ariel view of London---------------------------------------------------------------Detail of Extensive green roof---------------------------------------------------Chart depicting the timeline of the process using RIBA stages----------Timeline of installation of green roof in one week--------------------------

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BREEAM categories, sections and credits achieved------------------------Roles and Responsibilities of the stakeholders------------------------------RACI Metrics of the stakeholders------------------------------------------------

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TABLES Table 1: Table 2: Table 3:

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1 INTRODUCTION The procedure that will be implemented here is a Green Roof, and installing a green roof is not a difficult process to contemplate, but if it is not done properly, difficulties will arise later. But what exactly is a Green Roof? According to nps.gov, 2022 “A green roof is a layer of vegetation planted over a waterproofing system that is installed on top of a flat or slightly–sloped roof.” The extensive green roof grows on a shallow growing medium, usually, less than six inches requires minimal watering, and has a modest roof load(nps.gov, 2022).

Green roofs are one of the best processes to be implemented for a lower carbon emission practice in any type of building .but, implementing them in an Educational Building benefits in reducing the heat island effect and a green roof helps in the psychological wellbeing of the students(livingroofs, 2016). This makes the area more userfriendly and conserves resources.

As this educational building is being constructed in the west of London, the United Kingdom. According to an article, green roofs should be mandatory on buildings since providing more vegetation to a city like London, which has problems like the urban heat island effect, pollution, and flood risk, green roofs may assist a long way if they are placed on the majority of the buildings(Ing, 2021). The Image 1: Ariel view of London(Design for London, 2008) image on the right is from (Design for London, 2008) and depicts a city filled with buildings with green roofs.

BREEAM is the targeted certificate for this building by looking into BREEAM UK New Construction NON-domestic buildings (UK) technical manual(BREEAM UK New Construction 2018., 2018). By considering green roof as a process that affects the shell of the building it will help the building to achieve 21 credits i.e., 3 points in land use and ecology under sections LE 03 Management impact on ecology, LE 04 Ecological change, and enhancement, LE 05 Long term Ecological Management and maintenance; 1 point in Management under section MAN 04 Commission and handover; 1 point from Health and Wellbeing under section HEA 05 Acoustic Performance; 2 points from Energy under section ENE 04 low carbon design; 5 points in Materials under sections Mat 03 responsible sourcing of construction products, Mat 04 insulation; 1 point under waste under section Wat 02 use of recycled and sustainable sourced aggregates; 8 points under pollution under section Pol 02 local are quality, Pol 03 flood, and surface water management, pol 05 reductions of noise pollution.

This document describes Implementing of extensive green roofs on a new educational building in the southwest of the United Kingdom to achieve BREEAM certification. This is said by answering questions like; why this process is important? what are the information and tools needed to implement this process? How is this implementation process framed? When is this done? And who are involved in these implementation steps?

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2 WHY? WHY is a question that explains the significance of green roofs and their direct and indirect advantages, as well as a quick explanation of the BREEAM categories that green roofs attain.

Green roofs enhance building energy efficiency and save money while also benefiting the environment and biodiversity (nps.gov, 2022). It makes a substantial contribution to better stormwater management, lowering the urban heat island effect, and improving air quality (nps.gov, 2022). It also insulates the roof from heat and sound, extending the life of the roof. It also helps to improve the efficiency of mechanical equipment in the process of making it more energy-efficient (nps.gov, 2022).

The green life on the roof helps to reduce pollutants and greenhouse gases while also providing homes for insects and birds, both of which are threatened by urban expansion and the loss of natural spaces (nps.gov, 2022).

As indicated in the table 1 below, green roofs have an impact on the following BREEAM categories: land use and ecology, health and well-being, management, energy, materials, waste, and pollution. It contributes to the achievement of 21 potential BREEAM credits.

Table 1: BREEAM categories, sections and credits achieved By detailing the reasons behind the above table here, green roofs preserve small amount of the planet's flora and fauna, which has an impact on the ecology and aids in long-term changes in biodiversity, and green areas in the site have an impact on the site ecology. Green roofs aid in energy efficiency and will commission the building prior to and after handover by deducing the design and inbuilt performance. Whilst also reducing the sound of rain, the building's health and well-being improves. The building's shell has a low-carbon design because it has a green roof on top and saves energy. It also provides insulation for the roof and the building, extending the life of the roof. The materials used are environmentally friendly and recyclable; all of the insulating and water barrier materials can be recycled, and other plant materials can be converted into biodegradable trash.

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21039883 Pollution is one of the things that a green roof indirectly influences, as it regulates pollution and refines the air, controls heat in that area, improves water management and flood management by absorbing water, and decreases noise pollution entering the noise pollution. These are carried out both on the outside and inside of the structure.

According to the Fire performance of green roofs and walls, 2013 factors that are to be considered are the Slope of the roof; Wind Design; Prevention of Fire; provision of fire breaks. In the how part, it is discussed in detail why they are significant and how they will be examined (Barker, 2013).

3 WHAT? WHAT is the second question that inquiries about the requirements for completing the project.

Information, tools, and procedures are referred to as requirements in this context. The responsibilities under consideration here are working on the model's energy, structural, drainage, and roof water supply. The following questions will provide a full explanation of these tasks.

The first piece of information that should be distributed is a BIM model, which is required for creating and carrying out the subsequent processes. Second, any information linked to water supply, such as service information, the height of the building for water supply, and the plan for water input and outflow. Third, all the roof's structural characteristics and load-bearing capacity, roof slope, as well as its material index, are included.

The tools needed are divided into tasks, such as design, which is done in 2d and 3d software such as AutoCAD and Revit. The centralized model is maintained in a Revit shared file. The structural support of the roof is checked by S-BIM software robot structural analysis and water retention of the green roof is checked by ASTM-E-2399. The steady-state simulation of the building is not required for a green roof because energy decisions are not made at that stage, but Energy plus performs dynamic simulation modelling to compute energy efficiency and temperature exchange management.

4 HOW? HOW is a question that outlines the process of the actions that aid in the implementation of a green roof on a new building. This answers the question about the process, the sequence in which it is carried out, and who is involved in these specific duties.

Before we get into it, the most crucial item to consider before implementing a green roof is safety.

Roof protection layer material and substance growth media, fire breaks should be considered for fire safety purposes, according to The GRO green roof code, 2021 substrate depth, wind load, dead load, shear forces should be estimated and developed while constructing the roof (The GRO green roof code, 2021).These steps are aligned according to the RIBA stages the timeline will be shown below These factors should be considered while designing the hospital, notably because a green roof is being planned. The BIM manager creates a work plan that will be followed throughout the project. In the design phases of the project, the planning is done digitally in a single BIM Federated model. A federated model is a model that combines architectural, structural, and MEP models.

At first, the architect planned the roof with a minimum slope of 3 percent (1.8 degrees) and worked on the general arrangement of the roof with fire breaks, paths, and vegetation forms in mind. During the procedure, the MEP designer supplies water to the heights of green roofs and designs a drainage 4

21039883 system. The slope of the roofs and reservoir boards are developed when working on the drainage system. The structural engineer built the roof load to withstand the water and load while considering the shear stresses that would be applied by the green roof.

The structure is designed to accommodate a green roof faultlessly, and the contractor is assigned to install the green roof during the project's final phases of development. As depicted in image 2, a guidance to the layers of green roof installation. First, a waterproof membrane that functions as a vapor barrier and has insulation on top of it should be fixed, followed by root barrier plastic and a priority drainage matt. second, the sidewalls of the green roofs are framed to allow for optimal water flow, and soil is added which is function as a geotextile filter fabric. Finally, plants that are hardy and drought-tolerant are put here.

The Facility manager should give a BIM maintenance handbook with all instructions and a maintenance plan for the upkeep of the green roof.

Image 2: Detail of Extensive green roof (BRANZ, 2017)

5 WHEN? WHEN the question here allows us to determine the timeframe of the jobs that overlap with RIBA stages. The placement of various tasks on the project is done at a relevant period, as stated in the information above.

The green roof design is conceptualized in the RIBA level 2- Conceptual Design, 3- Spatial Coordination, and 4- Technical Design, as illustrated in the image 3.

The use of green roofs is investigated at the early Concept Design stage and when designing the Project's strategy. The design development process is discussed, as well as installation and maintenance approach. Consideration should be given to developing drainage, water supply, and structural support for the green roof throughout the design phase. In the Spatial Coordination stage of the building, there should be a designed plan for the green roofs that considers time (including the time required to install the green roofs in the project), cost (including the amount of money invested for green roof implementation and a rough estimate of future energy savings), sustainability (including its role in achieving BREEAM certification), and safety (i.e. checking its fire and safety plan for in use).

When the project is moved to the Technical Design stage The building should be ready with all the characteristics specified in the previous stage, and it should be fully planned to accommodate the green roof.

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Image 3: Chart depicting the timeline of the process using RIBA stages.

The installation and maintenance of the green roof are done in RIBA level 5- Manufacturing and Construction and 6- Handover as shown in the image 3.

The installation of the green roof takes place during the Manufacturing and Construction stage, as depicted in image 4 below. A green roof installation can take up to a week, depending on the surface area. The steps outlined in the HOW section are overlapping in the timeline below based on the time it takes.

Image 4: Timeline of installation of green roof in one week

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21039883 A manual of green roof maintenance is to be added to the list of maintenance papers at the Handover stage, along with all other maintenance documents. This should be handed out to the client along with the other building documents.

6 WHO? WHO The question here allows you to learn about all the stakeholders engaged in the process of implementing a green roof, as well as their roles and responsibilities and RACI assessment.

The stakeholders involved here are the Client, BIM manager, Architect, Structural engineer, MEP engineer, Contractor, and Facility Manager. The roles and responsibilities of the stakeholders are shown below in the Table 2

Table 2: Roles and Responsibilities of the stakeholders The RACI matrix below in Table 3 depicts the stakeholder responsibility assessment in relation to the takes. They are given the letters R-Responsible, A-Accountable, C-consulted, and I-informed. When someone is responsible for the task's completion, they are marked as responsible; when someone is accountable for completion, they are marked as accountable; when someone is responsible for advice and expertise and should be consulted, they are marked as consulted; and when someone is informed about the process and its completion, they are marked as informed.

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Table 3: RACI Metrics of the stakeholders Designing green roofs, designing drainage and water supply plans, structural support, fire safety, installation, providing maintenance plans, and maintenance are all tasks involved here. The client should be kept informed about all tasks during the execution of the green roof, i.e., should be informed about all actions. The BIM manager is accountable for task completion by facilitating collaboration and information flow among the other stakeholders. The architect is in charge of designing a green roof as well as offering a fire safety option for it, i.e., he is in charge of building a green roof with safety precautions to prevent fire spread. He can be consulted for all jobs included in the design stages, such as creating a water supply and drainage plan, as well as structural support. He should be consulted for any issues that arise during installation, as well as to provide a maintenance plan. While he is responsible for producing strong structural support for the roof, a structural engineer should be informed about the design and installation, and he can be consulted with other duties that are engaged in the design stage. Similarly, An MEP engineer is accountable for his own work, which is to develop a drainage and water supply plan, and he is brought up to date on the other tasks that are included in the design stages. The contractor oversees the installation, and the facility manager will be kept informed throughout the process. He is also in charge of supplying a maintenance manual and ensuring that the green roof is properly maintained. That is, he oversees the roof, plants lifecycle, and other parts of the green roof.

7 CONCLUSION The green roof is vegetated eco-roof and an extensive green roof is a a roof with less vegetation and less soil. The most considered economic benefits of the green roofs are that it helps in reducing energy cost and management cost of the building and the other indirect energy benefits to the environment are that it helps in reducing heat, reduces stormwater runoff, purifies air by reducing pollution, and 8

21039883 helps in psychological wellbeing. The green roof helps in achieving 21 BREEAM credits in the categories of land use and ecology, management, health and wellbeing, energy, materials, waste, and pollution.

It uses Energy plus for dynamic design performance tool, ASTM-E-2399 for green roof retention and robot structural analysis for checking structural support. The information needs to proceed with these deliverables are BIM model along with its structural and MEP data.

The designing of the green roofs is done in RIBA stage 2, 3, and 4, installation on stage 5 and handover in stage 6 along with the building handover. The major deliverables of the process are Designing green roof, drainage and water supply plan, checking structural support, checking fire safety, Installation, Provide maintenance manual and maintenance. These deliverables are done by BIM manager, Architect, Structural engineer, MEP engineer, Contractor, and Facility manager.

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8 REFERENCES Barker, C. (2013) Fire Performance of Green Roofs and Walls. p.36.

BREEAM UK New Construction 2018. (2018) (3), p.403.

Design for London (2008) Living roofs and walls [Electronic resource]: Technical report - supporting London Plan Policy. London, Greater London Authority.

Ing, W. (2021) Is the boom in green roofs and living walls good for sustainability? The Architects’ Journal.22 October 2021 [online]. Available from: https://www.architectsjournal.co.uk/news/is-theboom-in-green-roofs-and-living-walls-good-for-sustainability [Accessed 19 April 2022]. livingroofs (2016) Schools – learning through green roofs Livingroofs.12 July 2016 [online]. Available from: https://livingroofs.org/schools-green-roofs/ [Accessed 19 April 2022]. nps.gov (2022) Green Roof Benefits—Technical Preservation Services, National Park Service2022 [online].

Available from: https://www.nps.gov/tps/sustainability/new-technology/greenroofs/benefits.htm [Accessed 25 April 2022]. nps.gov (2022) What is a Green Roof—Technical Preservation Services, National Park Service2022 [online].

Available from: https://www.nps.gov/tps/sustainability/new-technology/greenroofs/define.htm [Accessed 19 April 2022].

The GRO green roof code (2021) GRO-Code-2021-Anniversary-Edition.pdf2021 [online]. Available from: https://www.greenrooforganisation.org/wp-content/uploads/2021/03/GRO-Code-2021Anniversary-Edition.pdf [Accessed 19 April 2022].

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