Future of Green BIM in achieving sustainable design, effective costing, and improved performances in Nigeria

Dr Amaka C. OgwuelekaPhD (Pretoria), Pg. C (UK), M.Sc. (NAU), B.Sc. (Enugu)

Senior Lecturer in Quantity Surveying & Construction LawUniversity of Uyo, Uyo

Akwa Ibom State, Nigeria

Introduction

The rise in advanced technologies has created platforms for the migration of new methods and products into the construction industry. The technologies that can benefit the industry, economy, and environment are those that can provide guidance for continuous improvement through the building lifecycle. Mismanagement of building information and changes can result in wastes and errors during design and construction phrases of a building project. This creates the need for technologies that can coordinate and manage the whole building lifecycle. The building industry came up with building codes and standards to regulate the design and construction of structures. In most cases, these codes and standards are not tailored towards specific local climate or culture which has stagnated the need to protect human health and environment. Project stakeholders have advocated for environmental friendly approaches to building projects which have attracted several new technological approaches.

In the last decade, the construction industry globally has experienced dramatic change in design and construction through the two recent trends, Building Information Modeling (BIM) and green building. This transformation gave rise to the terminology “Green BIM” which is coined from the two emerging trends. BIM is defined as the three dimensional digital representation of physical and functional characteristics of a facility from inception and design to demolition and materials re-use (NIBS, 2007). This shows the lifecycle view of a building from inception to demolition through digital modelling of different elements in real-time. BIM enables specific changes on the model and their impact on other variables like structures, loads, energy efficiency, and fiscal bottom line to be easily understood. Likewise, green technology (green building) involves maximising the conservation of resources (energy, water, land, and materials) of the entire life cycle of a building, protecting the environment, reducing pollution, providing people with healthy, comfortable and efficient use of space, and establishing a harmony of nature and architecture (Bonenberg and Wei, 2015).

Can a building be considered green without sustainability? Previously, the word “green” in the building industry has to follow up with an explanation to enable the people know that it is not the colour green but having an environmental friendly building project (Krygiel and Nies, 2008). Green building movement was brought to light through the formation of three different organisations, namely: American Institute of Architects (AIA), Committee of the Environment (COTE), and U.S. Green Building Council (USGBC). Sustainable design came into play which considers a greater array of impacts, not just natural environment. Ten measures of sustainable design and performance metrics were developed by AIA/COTE, and later, USGBC formulated the green building rating system under the scheme known as Leadership in Energy and

Environmental Design (LEED). The LEED program has recorded rapid growth through increased number of membership in USGBC and this has changed the course of design for project practitioners.

The construction industry is faced with the growing concerns of mitigating climate change, ensuring energy dependence, improving building efficiency and performances in cost-effective manner and that have propelled the demand for greener buildings and environment. The environmentally and socially responsible design solution has gone beyond sustainable design to how built environment can help to restore or regenerate the planet. This led to the formulation of new green building technology which explains the impacts of different levels of green for a proposed project, known as living building (Krygiel and Nies, 2008). The living building challenge was launched in 2006 which focuses on what the building does and not what it is designed to do (Cascadia Green Building Council, 2015). Living building is the living status of a building which has a zero net annual impact on the environment, provides its own energy and water, cleans its own wastes and emits pollution (Cascadia Green Building Council, 2015). The challenge adopts six areas for green building rating that include site design, materials, water, indoor environmental quality, and beauty and inspiration. There are 16 prerequisites stipulated by the programme to measure those areas.

Elements of sustainable design, effective costing, and project performancesIn some cases, sustainable design and green building are used interchangeably because they involve the four pillars of sustainability which include human, social, economic, and environmental sustainability (Goodland, 2002). This gives a direct answer to the previous question that a green building must be sustainable. The major ideal behind green building is to preserve the natural environment of a building project during design and construction without disrupting the land, water, resources, and energy in and around the building site. Kukreja (2016) identifies the benefits of green building within three sustainability pillars as follows:

(a) Environmental benefits include reduce wastage of water, conserve natural resources, improve air and water quality, and protect biodiversity and ecosystems; (b) Economic benefits are reduce operating costs, improve occupant productivity, create market for green products and services; and (c) Social benefits include improve quality of life, minimise strain on local infrastructure, improve occupant health and comfort.

Developing sustainable solutions for a building project requires the understanding of climate, culture, and place (Krygiel and Nies, 2008). Factors to consider in determining the climate conditions of a project site

include location, sun, temperature and dew point, rainfall, psychometric chart, wind, flora and fauna. The culture of people in the project environment differs from the culture of project organisation. The project team has to strike a balance between them. Every place is unique and has its own disposition, proper understanding of a place will assist to protect the existing natural systems.

Cost is incurred throughout the whole building lifecycle, the use of building technologies that improve performances will also reduce the project cost of a building. Effective costing of a building project requires a life-cycle perspective where all costs and benefits of a given project are evaluated and compared over its economic life. European commission (online) stipulates the key determinants of initial project cost and cost changing factors over time. The key determinants of cost are location, site, specification, tax liabilities, timescale, inflation, new build or refurbishment, and form of procurement contract. The cost changing factors are unexpected ground conditions, design changes, poor project management, land acquisition cost, inflation/relative price changes, force majeure, shortages of material/plant, exchange rate, inappropriate contractors, and funding problems. In economic terms, a building design is deemed to be cost-effective if it results in benefits equal to those of alternative designs and has a lower whole life cost, or total cost of ownership (Whole Building Design Guide, 2012).

Measuring project performance has gone beyond the triple constraints of quality, cost, and time to health/safety, environmental impact, client/user’s satisfaction, project team and many others (Kerner, 2013; Eriksson & Westerberg, 2011; Koelmans, 2004). Best practice can be achieved through proper alignment of the contractor’s objectives to achieve the client’s expectations for any particular project. It is therefore paramount to identify the objectives of all project stakeholders and expectations of the client at the commencement of any project.

How can we achieve green environment using BIM?BIM covers geometry, spatial relationships, light analysis, geographic information, quantities and properties of building components, project management and post-construction facilities management (Tim, 2015). This allows for the entire building system to be illustrated based on the functionality of BIM (n) D technology used. The dimensions are 3D BIM (visualisation, coordination, and clash analysis), 4D BIM (3D BIM plus time element), 5D BIM (4D BIM plus the estimating), 6D BIM (5D BIM plus sustainability), and 7D BIM (6D BIM plus facility management applications). The 6D BIM has the functionality of both 3, 4, and 5 dimensions of BIM and also provides sustainability element tracking, energy analysis, and LEED tracking and that is where green concept comes in. As previously stated, the new concept of green building is centred on maximising the conservation of resources such as carbon, materials, energy, and water in a building project with the intention of restoring and regenerating the planet.

The ability of BIM to predict outcomes of a building before construction makes it suitable for design and development of green built environment. Modeling of a facility using BIM will promote data rich, object-oriented, intelligent, and parametric digital representation of such facility thereby providing data for various analysis purposes. Performing sustainability analysis using BIM provides the Lifecycle Assessment (LCA) of entire building as it relates to the four resources of carbon, materials, energy, and water. The digital representation of conceptual designs using BIM can assist in identifying the low carbon options that have the potential to drive down carbon emissions during design and construction. This will lead to carbon saving and reduce overall environmental impact of building through its operation. The visual building can be used to analyse the feasibility of a project so as to design structures that reduce waste and optimise energy use. This will streamline the supply chain through more accurate procurement, evaluate energy efficiency, and make recommendations for design alternatives that will enhance a building performance. Space management in BIM can be used to quantify the amount of water usage in a building and also measure the potential for grey water re-use.

Case study analysisThe paper discusses the two case studies of green BIM adoption in both developed and developing countries in order to provide insight on how it can be effectively integrated into the building industry in Nigeria.

Case study I

Fehrenbacher (2011) reported on how BIM was adopted to design a greener facility as seen in the Miami Science Museum, USA. BIM was used to model how the solar strategies, water systems, and the space of the building impact ventilation thereby saving energy and reducing external resource needs. The solar conditions around the project site were analysed for the day and the year that helps to design the building shape, overhangs, and PV installations. This enables solar panels to be properly positioned for energy capture from sun and highly efficient thin PV to be installed to power up the building without interfering with the natural daylight. Passive and active solar design strategies were integrated to provide a mode for both heating and cooling of the facility.

However, the facility is situated close to a bay and BIM was used to analyse the water system so as to preserve the natural environment. Rain catchment and local bay were considered as sources of water exhibits for the museum. The roof surface is designed to harvest rainwater and store on grade in the car park area while the water excess is directed to the injection wells.Green roof and interior green wall were constructed to provide bio-filtration and also act as temporary means of rainwater retention for irrigation. The treated greywater is being used in toilets. Furthermore, BIM

was used to analyse the pattern of airflow on the site and also take advantage of the prevailing winds to design the building shape. The purpose of the building as a museum was put into consideration in modeling to determine the optimal roof form and height for effective cross-ventilation.

The use of BIM in Miami project gave way to a streamlined exchange of building information models, analytical data, and also to create a sustainable facility that would provide a model for future green initiatives.

Miami Science Museum, USA © Grimshaw Architects

Case study 2 The study conducted by Bonenberg and Wei (2015) assesses the impacts of green buildings using BIM in all aspects including lighting, energy efficiency, sustainability of materials, and other building performance. The international design competition of Tent Hotel organised in China was used to describe the green BIM adoption in planning and analysing the site location and building design. The competition provided the design requirements for the building project as follows (Bonenberg and Wei, 2015):

Mobile- mobile and convenient, with little or no permanent impact on the site;

Culture- reflecting local cultural elements, providing unique life experiences;

Eco-friendly- reaching LEED standards, fully embodying sustainable and low-carbon design principles;

Establishing BIM model to coordinate the designs; and

Analysis by simulating daylight, sunlight, shade, and sub-environment.

The available data on site location, climate condition, ecological value, site information, and transport infrastructure were used to generate 3D visualisation of the project. Resource sustainability considerations adopted for the building design were as follows:

Natural ventilation and lighting, and effective shading measures; Solar energy; Rainwater recycling and waste recycling; Outdoor use of permeable ground; Ecological maintenance; and Performance analysis.

The initial model provided a clear understanding about the site and the green analysis was used to generate options before a conclusion was drawn about the green parts. The study revealed that BIM can provide the basis for sustainable green building programs and conservation measures.

Tent Hotel-bird eye view (Bonenberg and Wei, 2015)

Tent hotel (Bonenberg and Wei, 2015)(a)daylight analysis (b) models analysis (c) simulation analysis (d)

masterplan

Impact of green BIM technology in achieving effective costing of building projectsThe process of going green can be expensive due to the costs of green materials and products. It is important to note that costing of a building is calculated based on the whole building lifecycle. The implementation of energy and sustainability analysis through green BIM will conserve energy thereby leading to cost and energy saving throughout the building lifecycle. The green BIM initiative is highly beneficial for reduction of operational and maintenance costs in building project (Rowe, 2013). Reduction in construction time and waste of materials/resources through green BIM initiative also contributes to cost reduction. Green BIM can effectively be integrated with lifecycle costing (LCC) to achieve the most effective costing from lifecycle perspective. Rowe (2013) stipulates that adoption of green BIM for LCC can be used to assess and forecast the cost and environmental impact of materials, equipment and technology. For example, the initial application of LCC in New Karolinska Solna hospital in Sweden has resulted in large margin errors and quickly outdated calculations as design phase progressed. The integration of green BIM to LCC has promoted lower lifecycle cost.

BIM tools are used to unite all aspects of a building project in one digital design having detailed information and specification for each aspect. It enables clients to budget for the costs of major elements of the building at the initial stage. It allows for all participants to fully understand the building both digitally and physically therefore enabling better decision making and more efficient processes that can cut costs and eliminate time wasted in rework. Properly optimisation in the planning stages will result in effective whole life value of the building. For example, the prices of items are captured to allow the sustainability and procurement of a building’s design to be accurately managed and forecasted. UK government forecasts that in 2025, BIM will help to reduce carbon emissions by 50 percent and construction cost by 33 percent (HM Government, 2016). This supports the study conducted by Wilding (2013) that maintaining efforts through green BIM to reduce carbon emissions will reduce construction by up to 20 percent. Therefore, it is important to note that minimising the negative impacts on a building project will help to reduce construction cost.

The way forward

With the use of BIM, we are able to move from documentation to parametric analysis of model data. The integration of new green building concept with BIM is driving toward restoration and regeneration of the planet, which can be referred to as “healing the earth”. Being able to overcome the challenges associated with green BIM usage such as misunderstanding, lack of clarity, and lack of skills, will allow for maximal utilisation of its benefits. Some of the BIM based software tools designed to support green building are Green Building Studio (GBS) for energy analysis, Ecotect analysis for building performance, 3D Studio Max for indoor lighting analysis.

“It’s time to think differently…it’s time to heal the future”- Martin BrownLet’s support the green BIM campaign!!!

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