Towards an Informed Readaptation

TOWARDS AN INFORMED READAPTATION

Application of Heritage Building Information Modelling (HBIM) in Adaptive Reuse in Kenya: The Case of Nairobi CBD

Brian Boit, Student, Department of Architecture and Building Science, Technical University of Kenya, Nairobi, Kenya

ABSTRACT: The previous four millennia have seen a rapid advancement in construction materials, techniques and technologies. Consequently, buildings now outlive their original users, and often, uses. To preserve the buildings’ functional and economic significance, these assets often undergo adaptive reuse. The adaptive reuse process – a linearly methodical process involving certain distinct technical tasks – as practiced locally, is sheet-based, uses the traditional linear workflow and often involves the use of manual tools. This exposes the process to a myriad of challenges. Heritage Building Information Modelling (HBIM) uses digital tools, is virtual model-based and employs a cyclic and collaborative Integrated Project Delivery (IPD) workflow. In the preservation and restoration of heritage assets, HBIM has been attempted with notable success. The noted success in choice conservation projects globally,persuaded the author that HBIM may offer significant value to the practice of adaptive reuse in Kenya since both processes involve the same technical task and workflows Unfortunately, a study of the level of HBIM adoption in the country is needful yet lacking. This research sought to investigate the progress of local implementation of HBIM in adaptive reuse projects, and suggest a possible approach that synchronizes the two paradigms based on the research findings. The overall intent is to facilitate a more efficient design and delivery of informed adaptive reuse solutions locally. An analysis of the correlation between challenges faced in the adaptive reuse process and the capabilities of HBIM suggests significantly numerous challenges which can be resolved using HBIM tools and processes. The survey indicated varying levels of implementation of HBIM depending on the task being tested. Further, there is generally a higher preference for HBIM in the adaptive reuse process. In conclusion, a nexus between the practice of adaptive reuse and HBIM can be created by the adoption of HBIM tools and employing the IPD workflow in the adaptive reuse process. However, many manual tools are still useful in performing some of these tasks hence should not be replaced but complimented by the HBIM tools.

Key words: Heritage Building Information Modelling (HBIM), adaptive reuse, HBIM adoption, Integrated Project Delivery (IPD) workflow

Paper type: Thesis summary

1. INTRODUCTION

The increased durability of buildings leading to them outliving their original users, deterioration due to the passage of time, need to sustain or improve building’s safety and comfort, legal requirements, the need for more control over the internal environment quality (IEQ) of buildings, and owner’s preferences have necessitated the modification of existing buildings, spaces, or infrastructure to accommodate new and different user aspirations through “minimal redevelopment and recovery interventions” in response to the evolution of the economies and societies that originally created them. This is termed adaptive reuse (Della Spina, 2021; Plevoets & Cleempoel, 2016). The adaptive reuse process is a methodical process going through various chronological stages and involving certain distinct technical tasks. The stages are initiation, assessment, options, project development, implementation and operation (Eppich et al., 2007).

Adaptive reuse, as practiced in Kenya, is sheet-based, uses the traditional linear workflow and often involves the use of manual tools. Unfortunately, this exposes the process to a myriad of challenges. These challenges include lack of documentation, difficulty (and, sometimes, impossibility) of conducting hand measurements, complexity of resolving information and data from different practitioners, difficulty in performing structural and environmental simulations using hand calculations, and struggle of identifying hidden structural members and Building Mechanical Services (BMS). These challenges complicate the detection of collisions, and preparation of costs, quantities and work schedules. Other challenges experienced are inaccurate visual aids and lack of a permanent record of the present conditions for future reference.

Globally, Heritage Building Information Models (H-BIMs) have been developed that contain and store all the information that pertains to an already existing building on the same digital model. Heritage (or Historic) Building Information Modelling (HBIM) is the application of BIM tools and workflow to existing buildings. Building Information Modelling (BIM) has had a widespread impact in the full lifecycle of new constructions, from design through to decommissioning. These benefits are also enjoyed when HBIM is applied in adaptive reuse. Intelligent conceptual designs facilitate a more accurate yet early cost estimation, intelligent schematic models allow for evaluation of a building’s functionality and sustainability, collaborative approach has led to a faster

project delivery, and modelled construction details results in a more accurate visualization and the automatic production of accurate and consistent 2D drawings upon design modification. Further, a federated model facilitates earlier conflict and error detection, virtual data storage avoids data loss, modelled information allows for automatic evaluation of building against design intent in terms of cost and time estimates, augmented reality and virtual reality facilitate a more immersive and interactive delivery of the final outcome, real-time cost assessment improves budget reliability, and better data quality enhances lifecycle building management (Eastman et al., 2008). Other benefits that are unique to as-built structures include faster, more accurate and more detailed documentation and interpretation due to digital surveyance of the existent structure, and a digital record of demolished assets. The implementation process of intervention measures has also gained from the ability to perform virtual inspections (Figure 1).

In light of the local need for, and the documented benefits of, adaptive reuse, the necessity of mitigating the various systemic challenges that dog the performance of adaptive reuse as it is practiced in the conventional linear, sheet-based process is paramount. Considering that the application of HBIM globally, with its principles of digitalization of tasks, automation of processes and interdisciplinary collaboration, has been shown to result in better outcomes, it is expected that HBIM adoption in adaptive reuse should be high. However, it is generally low, especially in Kenya. Furthermore, there is a lack of literature on HBIM application locally, and consequently, an inability to assess the potential of HBIM to meet the systemic challenges dogging the performance of adaptive reuse. A study of the level of HBIM adoption in the country is needful yet lacking. This thesis sought to identify and document this gap in knowledge, assess the progress of implementation of HBIM in the local context with respect to adaptive reuse, and suggest possible resolutions based on best practices internationally.

The overall objective of this study is to identify the nexus between HBIM and adaptive reuse, and highlight the potential of the former in facilitating and enhancing the efficient performance of the latter. This would be achieved by: (1) determining the extent of HBIM adoption in adaptive reuse; (2) establishing the relationship between the challenges experienced in the adaptive reuse process and the status of HBIM adoption in the process; (3) identifying and studying the impacts, positive and negative, of the application of HBIM in adaptive reuse locally; and (4) identifying and

studying the challenges facing the adoption of HBIM in adaptive reuse locally. By tapping into the computing capabilities of digital tools, the architect may be freed from the tasks of documentation, visualization, analysis, and simulation, by harnessing the speed, accuracy and efficiency of digital technologies perform these tasks, and this concentrate on the design aspect of the project. Considering the present agitation in the science and construction world for environmental conservation, the need for reuse and recovery of the existing building stock will only increase. This research will aid in facilitating the performance of such reuse actions.

2. ADAPTIVE REUSE

Due to the increased longevity of buildings, the present landscape is populated by building stock from previous time periods, some of which outlived their initial functionality necessitating adaptive reuse (see Table 1).

Table 1 showing adaptive reuse of common buildings in Nairobi CBD. Source: Author.

Figure 1 Benefits of HBIM to the adaptive reuse process. Source: Author

centre for natives from 1919)

Stanbic Bank 1910 Torr’s Hotel 1958 (to Ottoman Bank)

Nairobi Gallery 1913 Civil service building (then Nairobi PC’s office from 1963)

Westminster House 1928 Hotel

Banking

2005 Museum and national monument

1993 Banking

Sanlam House 1928 Upmarket office block Late 1940s Banking

Kenya National Archives

1931 Bank of India

1978 Archives

The extent of intervention during adaptive reuse may vary from minimal changes to the interior design and deco of spaces to introduction of whole floors, annexes and/or towers (see Figure 2 below).

d) Introduction of a building component, in this case, a stairwell. Source: Amy Frearson | Credits: dezeen. e) Introduction of additional floors. Source: Cei Materials.

2.1Theoretical Development of Adaptive Reuse

Modifying existing buildings to satisfy new functions is not a new phenomenon. For instance, classical monuments were given new uses during the Renaissance period, and during the French Revolution, religious buildings were confiscated and transformed to industrial or military buildings (Cunnington, 1988; Dubois, 1998; Linters, 2006). However, up to the 19th century, adaptive reuse was performed from a purely

Figure 2 Different extents of adaptive reuse including: a) Change of internal deco, Source: decoratist.com, b) Construction of new annex. Source: Architecture Lab. c) Introduction of a postmodern tower. Author: Alsandro, Wikipedia: Hearst Tower (Manhattan).

pragmatic perspective, concerned simply with financial and functional factors, and with no conscious concern for architectural parameters such as heritage preservation (Pérez de Arce, 1978; Powell, 1999). A theoretical framework for adaptive reuse was only established in the 19th century (Plevoets & Cleempoel, 2016) through the ideas of Eugène Emmanuel Viollet-le-Duc (1814–1879) who identified adaptive reuse as an approach towards architectural conservation. These ideas were advanced further by Alois Riegl (1858-1905), an Austrian art historian, who provided a theoretical framework for performing adaptive reuse on monuments with historical and cultural significance by defining significance and describing the place of functionality and history in his preservation.

The modernist school of thought built on the philosophy of rationalism was not particularly sympathetic of preservation of style or form of heritage buildings especially at the expense of functionality. The fourth CIAM congress of 1933, for instance, advanced that historic objects should only be preserved if the preservation does not result in poor living conditions for its users. Therefore, the paradigm started changing from being primarily about heritage preservation to being about preservation of functionality. Further, with the two world wars of the 20th century resulting in massive losses of building stock, the focus of adaptive reuse moved from being primarily on buildings from classical and medieval periods, to contemporary buildings with vernacular architecture, modernist buildings, industrial buildings and even whole cities (Choay, 1996). This change of focus paved way for the establishment of adaptive reuse as a paradigm distinct from architectural conservation.

2.2The Process of Adaptive Reuse

As initially highlighted, the adaptive reuse process is a linearly methodical process going through various chronological stages and involving certain distinct technical tasks. The adaptive reuse process is divided into six stages (Figure 5, Figure 4): initiation, assessment, options, project development, implementation and operation (Eppich et al., 2007).

During initiation,preliminary investigation is conducted by the various practitioners that constitute the design team. Geometric and non-geometric information about the building including dimensions, materials, history, site inventory and any other information relevant to the building is entered in the building inventory. In the case of historic preservation and facadism, the documentation of key character-defining

features is a significant step. Where renovations and retrofits are to be done, the detailing of the original electrical and mechanical systems is important to assess the need for replacement.

A detailed assessment of the building and site analysis is then conducted which generally includes interpretation of the data collected to identify the potential for adaptive reuse (e.g., Figure 3), the needs, opportunities, existing risks, and possible extents of readaptation. Government regulations and policies are considered, particularly zoning ordinances. The economic value, health and structural integrity of the building materials is assessed. Information from hand surveys is drafted, drawings are developed and distributed to architects and engineers for structural and environmental analysis and assessments (Sikka, 2007). A desk study of historical maps and archival documentation is also used to assess the building in light of its past and present context and usage (Chikwanda, 2007). This leads to preparation of different drawings.

Building on the documentation prepared detailing the architectural, environmental, structural and historical considerations, opportunities for intervention and modification are mapped out. The options are prioritized on the basis of cost, time needed for execution, complexity of proposed intervention, impact on existing fabric and historical and cultural significance of the building, and suitability to meet the new needs, among other factors. Taking advantage of visualization tools, these options are presented to all the relevant stakeholders and the best option settled for.

Figure 3 A sample site inventory showing structural elements that cannot be removed, and those that can be modified or removed. Source: MDPI

Once the best option is appointed though still at a schematic design level, the brief is developed showing the scope of work and other necessary details, including schedules and necessary costs. Detailed architectural and structural drawings are drafted, bills of quantities prepared and work schedules developed. The adaptive reuse work is then implemented, i.e., the construction phase. Finally, the building is occupied for operation (Eppich et al., 2007)

2.3Indicators of Success in Adaptive Reuse

An architect’s primary concern in the adaptive process is the successful design and delivery of an aesthetically-appealing, functional, cost effective, structurally sound and comfortable design solution that meets the needs of the client. Several questions must then be answered to assess the success of the adaptive reuse project.

Figure 4 All approaches generally follow the same process in the conventional system. Source: Author

Figure 5 The adaptive reuse process. Source: Author (2021)

a. In light of the needs and architectural style of the area, does it fit into location?

b. Does it preserve and highlighting key character-defining features?

c. Does it make use of proper materials, e.g., preservation of the old materials for their sustainability and conservation benefits? Do the materials conform to existing legislations? Have all the materials that pose health challenges been eliminated?

d. Is the resultant space flexible or readaptable?

e. Are the principles of environmental sustainability applied in the project?

f. Has successful masterplanning and landscaping been implemented to complement the readapted building or space?

g. Besides environmental sustainability, has user comfort and experience been taken into consideration, including provision of optimum Building Mechanical Services and spatial provision and organization?

h. Has user safety, including fire safety and structural integrity, been considered?

g. Was the project implemented within the projected cost and time schedule?

Figure 6 Indicators of success in adaptive reuse. Source: Author

2.3.2 Challenges experienced in the adaptive reuse process

Adaptive reuse, as practiced locally, is sheet-based, uses the traditional linear workflow and often involves the use of manual tools. Unfortunately, this exposes the process to a myriad of challenges.

First, adaptive reuse deals with already built structures, many of which are generally old, and largely lacking in digital documentation, especially in the Kenyan context. Hand surveys to document them are often laborious (and sometimes impossible), labour-intensive, and often suffers from inaccuracies. Sketches may often miss critical details. Further, in the absence of previous documentation, observing the interaction and integration between architectural, structural, electrical and building mechanical systems in a sheet-based model may prove difficult. Reproduction of key characterdefining features, particularly in classical buildings, is also a hectic and timeconsuming process.

In addition, since adaptive reuse of old buildings involves a huge amount of information, ranging from drawings, through 3D models, to textual information such as the age and history of the building, resolving these different pieces and kinds of information may be complex. To make it worse, in the absence of a common platform for submission and structuring of information from different designers, keeping track of design suggestions, comments and changes is difficult. Consequently, the challenges above make scheduling the work and estimating its cost to be complex, and resolving the work-plan across different professions to be hectic. Often, collisions that could have been resolved on model end being discovered on site (Figure 7)

In some cases, proposed solutions may need structural or environmental simulations, which are arduous to perform using hand calculations and drawings. Furthermore, adaptive reuse involves repurposing of the original space,for which thereis often need for visualization of the final use. However, the accuracy of visual aids depends on the

Figure 7 Clash between two structural members, and between a structural member and a plumbing component. Source: IMS Info

accuracy of the base digital model (Figure 8). Finally, other buildings may come to the end of their life cycle and, for whichever reason, require decommissioning. In the absence of a physical or virtual model, such a building will lack a record of its existence for posterity, or if preserved through photographs, cannot be appreciated immersively by future viewers.

In light of these challenges facing the adaptive reuse process (Figure 9), this research will appeal to technology in pursuit of a solution.

Figure 9 Challenges facing the adaptive reuse process and hindering success. Source: Author

Figure 8 A comparison of render and reality for New York's The Vessel. Source: Forbes Massie Heatherwick Studio and Getty Images

3. HERITAGE BUILDING INFORMATION MODELLING (HBIM)

Heritage (or Historic) Building Information Modelling, (HBIM) is the application of BIM tools and workflow in existing buildings. Traditionally, drawings were drafted by hand before the advent of 2D CAD. Then 3D CAD modelling was introduced, facilitating 3D visualization and auto-generation of drawings. Other aspects of geometric (i.e., physical) and nongeometric building information (see Figure 10), technically called “dimensions”, were added, including quantities, cost, sustainability and security features, among others, making the CAD model a Building Information Model. This process is termed Building Information Modelling and results in a model-based approach to design, which is a departure from the earlier sheet-based approach.

In the manipulation of already-built structures, these kinds of information are needed also. The key difference is the need to model building information as it is, and modify the building within its own constraints. The key task of the modeller is to reproduce existing conditions in a virtual model (Figure 11) called Heritage Building Information Models (H-BIMs).

In 2009, Heritage-BIM or Historic-BIM was first identified as a specific paradigm (Murphy et al., 2009), then solely applied to restoration of heritage assets, hence the ‘Historic’ or‘Heritage’inHBIM.However,the tools andprocessesemployedinHBIM were noted to be applicable in other exercises that involve the manipulation of already-built

Figure 11 BIM is used for new constructions which often employ modern technologies. HBIM is used for existing buildings which used older technologies. Source: DVA Architects

Figure 10 Graphical and non-graphical information in a BIM model. Source: Breakwithanarchitect

structures, including renovations, retrofitting, demolitions and new additions. Consequently, HBIM became a paradigm distinct from architectural conservation.

3.1The Capabilities of HBIM

HBIM technologies have a wide variety of capabilities and benefits applicable to the process of manipulating as-built buildings. Error! Reference source not found. below summarizes these HBIM capabilities.

HBIM CAPABILITIES SUMMARY

scanning and documentation

HBIM tools (e.g., photogrammetry, Figure 12, and 3D laser scanning) capture geometric information and converts them to CAD models which can then act as base BIM models for further manipulation or storage.

3D modelling

This includes topographic modelling and modelling of the architecture.

Topographic modelling: HBIM tools collate data from GIS and 3D laser scanning technology to model topographic data or import data from satellite imagery on platforms like Google Earth.

Architectural modelling tools model the target objects to the desired level of development augmenting all desired graphical (e.g., layers in composites, complex wall profiles, and ornamental architectural details) and non-graphical (e.g., physical and chemical properties of materials, loadbearing properties and age) information to the

Figure 12 Photogrammetry develops 3D models by taking multiple overlapping photos of the whole surface of the target object then combining them into a 3D image. Source: Formlab

Analyses and simulations

resultant HBIM model. This enables detailed coordination between disciplines, e.g. clash detection/avoidance, layout comparisons, etc (BIMForum, 2015).

In projects containing components with complex forms, modelling software employs visual programming where complex shapes are reduced to mathematical equations for manufacturing equipment to recognize and process them.

Where there are key character-defining features, 3D scanning tools capture the minute architectural details to the desired level of accuracy and detail.

A key feature for adaptive reuse in architectural modelling tools is renovation modelling where the modeller can mark components to be retained, introduced or demolished for simulation of structural integrity, indoor space use, clashes, and visual appearance, and documentation of building history.

Different tools exist that offer the capabilities of performing different kinds of analysis and simulations.

Conceptual and schematic modelling tools facilitate conceptual modelling for preliminary analyses and simulations, e.g., massing (Figure 13), energetic or solar analysis (Figure 14); and visualization purposes

Figure 13 Conceptual massing models are used in urban design for massing studies. Source: Shoegnome

Structural analysis tools (e.g., Robot Structural Analysis, STAAD and SCIA) enable either preliminary or detailed structural analysis of an HBIM model. They can also be connected to non-destructive structural testing tools (NDTs) for structural integrity testing of existent buildings relying on radiation, sound, or electromagnetic signals for detecting cracks in structures (Figure 15) or laser scanning for damage detection in timber structures (Mol et al., 2020; Tonelli et al., 2020).

Environmental analysis tools (Ecotect, Green Building Studio and Sefaira) enable either preliminary or detailed environmental analysis of an HBIM model.

Architectural modelling and/or model checking tools enable automatic detection of clashes between models from different practitioners. This is important in adaptive

Figure 15 Non-destructive methods of testing concrete. Source: The Constructor

Figure 14 A conceptual model made using FormIt being used for solar analysis in Autodesk Insight. Source: Pinterest

visualization

reuse specially to check for clashes between the existing members and the proposed modifications.

4D-BIM and 5D-BIM tools allow for simulation of cost and construction schedule of a project, respectively.

Accurate HBIM modelling result in more accurate visualization

Use of technologies such as virtual reality and augmented reality facilitate a more immersive and interactive visualization, or a digital record of demolished assets (see Figure 16 and Figure 17).

interdisciplinary collaboration

A combination of a federated model, detailed modelling and immersive visualization facilitates the storage of existing conditions for future reference.

BIM software interoperability (i.e., the ability to import and export virtual models across different BIM software, Figure 20) has facilitated interdisciplinary communication.

Figure 17 VR creates an entirely new and separated virtual environment. Source: The American Society of Mechanical Engineers

Figure 16 AR overlays proposed solutions on the existing structure. Source: The New York Times

A cloud-based Common Data Environment (CDE) provides a virtual platform where stakeholders can upload information and comments pertaining to the same model and communicate in real time (Figure 19). BIM collaboration software include BIM 360, Trimble Connect and BIMx.

Figure 20 IFC translates models made by one software into information that can be used by a second software. Source: LinkedIn

Figure 19 Traditional Information sharing vs using a Common Data Environment (CDE). Source: bimspot

Figure 18 Source: ResearchGate

A federated model (i.e., a single model integrating models from different practitioners) enables simultaneous manipulation of an HBIM model (Figure 18).

3.2The HBIM Process

With the bouquet of functionalities and capabilities highlighted above, particularly cloud-based collaboration, HBIM demands a new workflow built on a collaborative approach that integrates the real-time multidisciplinary input of every key player. This necessitates the HBIM Process.

3.2.1 Integrated Project Delivery

The approach to design and construction that supports simultaneous multidisciplinary involvement in the design and execution of a project is termed Integrated Project Delivery (IPD). By reducing incentives for conflict, it provides a continuity of information flow from start to finish, and eliminates most of the opportunity for communication error. It enables greater optimization of all needs from start to finish and facilitates incorporation of sustainable strategies (Phuc, 2012). This is in contrast to the tradition project delivery that is fragmented, linear and sheet-based. The table below highlights the difference between the traditional project delivery and integrated project delivery (AIA, 2007)

Characteristic Traditional Project Delivery Integrated Project Delivery Teams

Fragmented, assembled on just as need or minimum necessary basis, strongly hierarchical, controlled

Process Linear, distinct, segregated; knowledge gathered “just as needed”; information hoarded; silos of knowledge and expertise

An integrated team entity composed of key project stakeholders; assembled early in the process, open, collaborative

Concurrent and multi-level; early contributions of knowledge and expertise; information openly shared; stakeholder trust and respect

Risk Individually managed, transferred to the greatest extent possible

Compensation/ Reward Individually pursued; minimum effort for maximum return; firstcost based

Collectively managed, appropriately shared

Team success tied to project success; value-based

Communication/ Technology Paper-based, 2 dimensional; analogue Digitally based, virtual; Building Information Modelling (3,4 and 5 dimensional)

Agreements Encourage unilateral effort; allocate and transfer risk; no sharing

Encourage, foster, promote and support multi-lateral open sharing and collaboration; risk sharing

4. PRECEDENT STUDY: RESTORATION OF PESCHERIA DI GIULIO ROMANO BY DVA

DVA, the firm behind the restoration of Pescheria di Levante in Mantova Italy, embraces a whole life-cycle approach to design. Restoration Process/Workflow

4.1.1 Team assembly

The design team included the architects (who doubled up as HBIM modellers), BIM consultants (who advised on how to make optimum use of the capabilities of the HBIM tools) and laser scanning consultants, among others.

4.1.2 Site inventory: scanning and documentation, including hidden components

The technical work commenced with collecting physical data on site using photography and laser scanning survey (Figure 23a). Key character defining features were laser scanned facilitating a quick reproduction of the components.

Figure 21 Software used in data processing and creation of HBIM model. Source: DVA

Figure 22 Data processing and creation of HBIM model: from laser scanner image to HBIM model. Source: DVA

Figure 23 (a) 3D laser scanning in progress, and (b) a sample 3D laser scan. Source: StudiopdA

4.1.3 Historical research

A historical research followed with past maps and drawings collected and interrogated (Figure 24) to gain the non-geometric knowledge contained in the fabric of the structure.

Information from the historical research was augmented into the HBIM model developed from the laser scanning survey (Figure 25). A balance had to be stricken between modelling the form as is with the impact of age, and wear and tear (i.e., real HBIM model), and modelling it as it ought to be, or as it was when it was new (i.e., ideal HBIM model). This balance was dependent on ability of software, technical expertise and time needed to model the real (Figure 26).

Figure 25 Data collection for model development. Source: DVA

Figure 26 Translating the complexity of the historical building into the HBIM model. Source: DVA

Figure 24 Original plan (1831), artistic impression (1829) and elevation and plan (1882). Source: DVA

4.1.4 Element classification and library creation

Since the laser scanner picks the whole building as a single object, the HBIM model was then fragmented into the different elements of the building. These elements were classified appropriately with all the non-geometric information added (Figure 27), creating a digital information database of building components containing associated materials, component characteristics and specifications, historical information, and component condition.

4.1.5 Theorizing solutions

The design team then theorized on the restoration strategy to be employed. Eventually, certain portions of the project were restored to the original look, other portions were preserved as impacted by age, others demolished or modified, and other portions modernized, particularly the interior spaces.

4.1.6 Renovation modelling

To automatically calculate the volume of material change, check for clashes between the new constructions and the existing building, evaluate structural risks to be occasioned by the demolitions, and to visualize the final product in comparison to the original, the architect used renovation modelling, where the demolished elements are colour-coded yellow and the new constructions are colour-coded red. Further, the architect could hide, or reveal, by a simple press of a button, the elements to demolish, the elements to be introduced and/or the unaffected elements.

Figure 27 Element classification. Source: DVA

4.1.7 Interdisciplinary collaboration and development of a federated model

Interdisciplinary collaboration involved virtual communication and information sharing in a Common Data Environment (CDE) provided by BIM Factory™ where documents, comments and reviews were shared and organized according to the specified protocol for easy access; and collaborative manipulation of a federated model (Figure 29).

Figure 29 Working on a federated model with addition of MEP information. Source: DVA

Figure 28 Renovation modelling: highlighting the demolitions and new constructions. Source: DVA

4.1.8 Clash detection, cost simulation and project scheduling

These simulations were done as summarized in Table 2.

4.1.9 Visualization

A significantly high level of detail and accuracy in the models resulted in a significantly high level of accuracy in the photo renders (Figure 31, Figure 30).

Beyond photorendering, visualization was also used in project management by employing augmented reality (AR). Construction site activities were tracked using a combination of the SYNCHRO Site™ app and Microsoft HoloLens™, a pair of mixed reality smartglasses. Therefore, the architect could compare, in real time, the ongoing construction with the HBIM model and identify discrepancies. The software enables tagging, visual status monitoring and reporting so that the architect could make comments virtually on site and the comments would be stored in the CDE for future reference.

4.1.10 HBIM for future reference

Since the project was comprehensively modelled as a HBIM model, future users can always perform a virtual tour of the Pescheria de Giulio Romano as it was before restoration. Further, future clients will have a permanent 3D record of the original

Figure 30 Detailed modelling results in a more accurate representation of the actual structure. Source: DVA

Figure 31 Different views into the project and their respective white-model renders. Source: DVA

project and the changes made in case they will ever want to revert to the prerestoration look.

4.1.11 Application of HBIM Tools

Previous sections have highlighted the adaptive reuse as comprising several key tasks. The table below highlights and summarizes the HBIM capabilities which were employed in the workflow documented above to perform these adaptive reuse tasks.

Table 2 HBIM capabilities employed in Pescheria di Giulio

Adaptive reuse task

1) scanning and documentation

2) topographic modelling

3) modelling key character-defining features

4) analysis of design options

5) interdisciplinary collaboration

HBIM capabilities

3D laser scanning on Leica CloudWorx™, mesh creation on MeshLab™, solid modelling on Rhinocerus™, element classification on ArchiCAD™

Not done

3D laser scanning

Not done

Virtual communication on BIM Factory™, federated model on ArchiCAD™

6) structural analysis Not done

7) environmental analysis

8) clash detection

9) renovation modelling

10)visualization

Not done

Automatic clash detection on Tekla Bimsight™

Renovation tool on ArchiCAD™

Photorendering on ArchiCAD™, augmented reality using SYNCHRO Site™ and Microsoft HoloLens™

11)documenting existing condition for future reference

12)cost simulation and construction scheduling

Detailed model and render saved for future reference

Construction scheduling on TeamSystem’s SYNCHRO PRO™, quantity take-offs on TeamSystem’s CPM™

4.1.12 Benefits of HBIM to the Adaptive Reuse Process

First, the digital surveying provided exact measurements. In light of the size of the project, the 3D laser survey was a timesaver. The survey also provided comprehensive information of the form of the building, including of elements which were partially or fully hidden from human sight. This enabled a comprehensive analysis of design needs and a theorizing of broad solutions. Moreover, the digital surveying enabled the accurate reproduction of key character defining features for visualization and construction. Further, this digital model can be used to 3D-print the components in case need arises in future.

Second, the classification and properties metadata provided item information, e.g., dimensions, finishes and related document information, including non-graphical information derived from the historical research. This information was useful for automatic clash detection, decision-making about project and its costs, and virtual accessibility by other stakeholders including approving bodies.

Finally, the final models were possible to be shared in a more complete and immersive way. Virtual reality (VR), provided a greater awareness of the project to stakeholders who were not construction professionals. Augmented reality (AR) facilitated efficient supervision of project to ensure the constructed solution adhered to the designed solution.

Some challenges were experienced during the modelling process. For instance, the architects experienced difficulty in reconciling parametric modelling with the complex surfaces and features of historical heritage. In addition, while the theme of representation in architecture is the most developed field of research, the representation of the aging and restoration process as a whole still remains relatively unexplored.

4.1.14 Evaluation of the Application of HBIM in Pescheria di Giulio Romano

A study of the use of HBIM in the restoration of Pescheria di Giulio Romano showcases the capabilities of HBIM in the documentation, simulations and analysis, visualization and management of projects to facilitate efficient delivery of accurate and timely adaptive reuse solutions. However, the study has also highlighted the limitations of existing HBIM technologies in the simulation of the impact of age on buildings. This limitation may affect visual simulation of the project.

4.2Conceptual Framework: A HBIM Approach to Adaptive Reuse

Thus far, both adaptive reuse and Heritage Building Information Modelling (HBIM) have been reviewed as distinct paradigms. This research will now interrogate the opportunity for, and possibility of, their synchrony in such a manner as to employ the technology to enhance the practice.

4.2.1 A HBIM Approach to Adaptive Reuse

This is an integration of BIM tools and processes to the conventional adaptive reuse process to increase speed, accuracy and efficiency of the adaptive reuse exercise.

4.1.13 Challenges experienced in application of HBIM

DENSE CLOUD STATE-OF-THE-ART PHOTOGRAPHY MODEL

Figure 32 From dense cloud to digital mesh: loss of information on age and deterioration. Source: DVA

4.2.1.1. Initiation

The design team develops a BIM Execution Plan (BEP) detailing the adaptive reuse process, the responsibilities of every member, the BIM tools and processes that will be employed and the project milestones.

4.2.1.2. Building survey

Appropriate and accurate methods of data capture are employed, particularly scanto-BIM, converting the physical building to a manipulatable digital model. Hidden components are also captured in this process. The building is modelled to a high level of development (LOD) as specified in the BEP.

4.2.1.3. Assessment

Structural, environmental and BMS simulations and analysis of the existing structure using the BIM model is done. Possible barriers and enablers of the intervention process are identified, including zoning ordinances and existing regulations are identified.

4.2.1.4. Options

Possible interventions and modifications are theorized. Conceptual designs are modelled using BIM modelling tools and preliminary simulations and analyses performed. The options are presented to the client, potential users and the community (as is applicable) using virtual reality (VR) and augmented reality (AR). The best option is appointed.

4.2.1.5. Project development

The project brief is developed and updated. The project timeline is set and milestones defined.

4.2.1.6. Implementation

A 5D-BIM Model of sufficient LOD to capture all components, assemblies, manufacturer’s information and all other data relevant to the project is developed. The design team performs the various simulations and analysis needed. The resultant model, now a “digital twin” of the project that will be implemented, is presented to all key stakeholders outside the design team using VR and AR. The BIM model is submitted to the approving bodies together with the results of the various simulations.

Construction of the final solution is then performed based on the costs and time schedules in the 5D-BIM Model. The adherence of the project to the design costs and

time schedules is progressively checked. Laser scanning can also be employed during project inspections to check for structural weaknesses in the project.

4.2.1.7. Handing Over

All the information developed in the course of the design and construction and uploaded in the CDE is collated as the Project Information Model (PIM) and handed over to the client alongside the readapted building or space. The information pertinent for facility management is segregated and stored as the Asset Information Model (AIM) to be used for the operations and maintenance of the space.

5. RESEARCH METHODOLOGY

The methodology adopted in this research comprised of a study of literature and case studies in relation to HBIM use in adaptive reuse projects; and survey research with two rounds of survey. The primary concern for this project is on the project design and delivery process. The architect being most in tune with this process, was the key stakeholder engaged via digital questionnaires distributed virtually. The questionnaires tested for application of HBIM in various tasks that constitute the adaptive reuse process. The data obtained was then quantitatively analysed, interpreted and the findings presented. Finally, the data obtained was discussed to establish fulfilment of the research objectives.The author then made his conclusions,recommendations and suggestions for further study.

Figure 33 Integrating a HBIM approach to the present process of adaptive reuse to mitigate against the challenges faced. Source: Author

6. DATA ANALYSIS, INTERPRETATION AND DISCUSSION

6.1Discussion

This research set out to bridge the gap between adaptive reuse and HBIM, by learning from international best practices and recommending strategies for local application of HBIM in adaptive reuse. The overall objective was to create a framework for synchronizing adaptive reuse and HBIM to facilitate a more efficient design and delivery of informed architectural solutions in Kenya. This would be achieved by: (1) establishing the relationship between the challenges experienced in the adaptive reuse process as practiced in Nairobi and the status of HBIM adoption in the adaptive reuse process; (2) determining the extent of the adoption of HBIM in adaptive reuse in Kenya; (3) identifying and studying the impacts, positive and negative, of the application of HBIM in adaptive reuse locally; and (4) identifying and studying the challenges facing the adoption of HBIM in adaptive reuse locally.

Consequently, several pertinent questions needed to be addressed by this research. The key question was, how can HBIM be employed to facilitate a more efficient delivery of the adaptive reuse process locally? This question would be answered by tackling several sub-questions and collating their responses.

6.2Survey: Background

6.2.1 Response rate

The study population was the 800 registered members of AAK and since this number was accessible virtually, a census was undertaken where questionnaires were sent to all the respondents. From the 800 questionnaires sent, 33 were returned which represented a response rate of 4%. Whereas this response rate looks low, there is no definitive rate of response that is widely accepted as enough for mail, e-mail and digital surveys due to a non-response error occasioned by the undelivered requests for response that cannot be accounted for The lack of account is due to difficulty of ascertaining whether email or SMS has been received and read. Further, lack of incentives to fill the questionnaire and length of questionnaire (particularly if response time is more than 30 minutes) results in low response rate for online survey (Deutskens et al., 2004).

The majority of the respondents were graduate architects (51.6%). Further they fell into the 26-30, 31-35 and 36-40 age ranges, and had 5-9 or 10-14 years of experience. Majority had handled two or less adaptive reuse projects (45%) and even more (87.9%)

had handled two or less adaptive reuse projects using HBIM. They also indicated they had been using HBIM for less than 5 years. Most of the respondents did modelling and building survey, and a majority of them preferred ArchiCAD (70%) as their modelling software.

While SketchUp is not a BIM tool but a 3D CAD tool, Graphisoft’s ArchiCAD and Autodesk’s Revit are BIM tools and tools can perform accurate modelling, simulations and analysis, renovation modelling, component modelling, and clash detection among other BIM processes.

6.3Summary of major findings

The aim of this study was to establish the status of adoption of HBIM in the adaptive reuse process in Nairobi County, Kenya. The major findings of this research together with their corresponding objectives are listed in the table below;

Objective Finding

i. To establish the extent that challenges experienced in the adaptive reuse process affect the adoption of HBIM in adaptive reuse locally.

It was established that the challenges faced in the adaptive reuse process are the challenges typically associated with the conventional manual process. Ironically, in some cases, the conventional process was still preferred despite the challenges experienced. However, it was also noted that some of the challenges are associated with the HBIM tools and processes, particularly the cost of implementation of solutions and the need for software expertise. These two may account for the preference of the conventional method.

ii. To assess the extent of adoption of HBIM in the process of adaptive reuse in Kenya.

It was determined that HBIM tools and processes have been adopted to different extents across different steps in the adaptive reuse process. This challenges the traditional notion that the level of adoption of BIM and HBIM is low locally. However, these HBIM tools are still adopted within the framework of the traditional process to facilitate and enhance it, and not within the framework of the HBIM process, i.e., the Integrated Project Delivery (IPD) workflow.

The main benefits enjoyed in adopting HBIM were:

i. Efficiencies from reuse of data or details (enter once use many)

iii. To identify the benefits accrued in adopting HBIM in adaptive reuse in Kenya.

ii. Reduced redesign challenges during project implementation

iii. Earlier and more accurate design visualisation

iv. Improved communication between project parties

v. Improved project information management.

The main challenges experienced in adopting HBIM were:

iv. To identify the challenges facing the adoption of HBIM in adaptive reuse in Kenya.

i. High cost of buying and updating software

ii. Lack of knowledge of BIM application by stakeholders

iii. Lack of BIM standards

iv. Inadequate finance in small firms to start new workflow system for BIM.

6.3.1 Challenges experienced in Adaptive Reuse

The process of adaptive reuse was observed to be dogged with challenges postulated during the literature review and established through the study of a local

case and an analysis of the survey responses. Most of the challenges identified were connected to the manual, sheet-based approach due to the limitation of hand tools; difficulty of simulations and analysis; challenge in comparisons of drawings to identify clashes; time taken to perform activities manually; and inaccuracies in documentation, modelling and visualization; among others. However, other challenges were also connected to the implementation of HBIM technologies in the process including complexity of some digital tools, high cost of procuring tools and expertise, and lack of expected capabilities in some HBIM tools.

The challenges noted from the survey are consistent with the challenges identified in the literature review. However,the research identified even more challenges than had been documented, and gave them as they are experienced in the Kenyan AEC market.

6.3.2 Opportunities of adoption of HBIM in adaptive reuse to enhance success and/or mitigate challenges faced

An analysis of the correlation between challenges faced in the adaptive reuse process and the capabilities of HBIM suggests opportunities that the local AEC industry offers for the adoption of HBIM. The challenges of inaccessibility of as-built drawings; greatly metamorphosed buildings with little resemblance to the original drawings (and especially with the changes or alterations not captured on any drawing);inaccuracies occurring during measuring; discrepancies between the measurements on site and drawings; difficulty and time need to perform manual measurements offer an opportunity for adopting 3D laser scanning, photogrammetry and similar 3D scanning technologies for surveying, measurements and documentation.

The challenges experienced in documenting hidden structural members and Building Mechanical Services (BMS) also offer an opportunity for adopting non-destructive testing methods to assess the structural integrity and location of BMS in a building, particularly where the original drawings are unavailable or insufficiently detailed.

The challenges experienced in topographic modelling include inaccuracies or imprecision of Google Earth terrain and amount of time and effort needed to model terrain from contours or reconcile imported terrain and actual site creates an opportunity for the adoption of 3D imaging of site. However, further technological advancement may still be required before accuracy of contours can be attained on virtual models of the global terrain.

The challenge experienced in modelling of key character-defining features is high complexity of features resulting in high amount of time and effort needed to reproduce the features. This may be resolved through the creation of HBIM libraries by architects involved in documenting as-built structures and sharing them on commonly accessible platforms. 3D scanning may greatly aid in facilitating a faster and more accurate performance of the reproduction process.

The challenges experienced in interdisciplinary collaboration including non-responsive professionals and low level of HBIM knowledge and awareness among other professions require increased training. However, the industry needs an impetus to do this, an impetus which may come from the architects as the de facto creators of HBIM models and institutors of the projects. This will also resolve the main challenge faced in clash detection, which is caused by lack of federated models that can perform automatic clash detections virtually.

One of the challenges experienced in visualization is inaccurate renders coming from lack of accurate modelling. HBIM models with a high level of development will result in more accurate representations of the project as it shall be once executed.

It can, therefore, be safely concluded that a relationship exists between the challenges experienced in the adaptive reuse process as practiced in Nairobi and the status of HBIM adoption in the adaptive reuse process due to the significantly high number of challenges which can be resolved using HBIM tools and technologies.

6.3.3 Level of adoption of HBIM in Adaptive Reuse

The survey indicated varying levels of implementation of HBIM depending on the task being tested. Activities such as topographic modelling, modelling of key characterdefining features, environmental analysis, structural analysis and renovation modelling had a high level of application of HBIM technologies. Activities such as documentation of hidden members, survey and measuring, interdisciplinary collaboration, clash detection, visualization, facilities management and documentation for future referencing had a low level of application of HBIM technologies. Analysis of design options had an average level of adoption of HBIM technologies. Unfortunately, while the research tested for the architect’s preferences of the tools, it did not test for the frequency of use or the success thereof. Moreover, the questions were tested on a Likert scale indicating a high level of preference for most HBIM tools and processes by the practitioners who have implemented them. Nonetheless, while the impact of HBIM

adoption may be suggested by the high positive perception of HBIM tools and processes by the respondents,the impacts – positive and negative – of the application of HBIM in adaptive reuse locally was not empirically measured.

6.3.4 Impact of HBIM adoption to adaptive reuse

As stated above, the survey indicated a varying level of HBIM application depending on the task being tested. However, the answers on the Likert scale also indicated a generally higher preference for HBIM in the adaptive reuse process. The local case study argued that success in adaptive reuse can still be attained while applying manual tools. However, some of the noted challenges resulting in time losses, reworks and cost overruns can be resolved by application of HBIM tools. Further, an implementation the HBIM model of work, i.e., the IPD workflow, will facilitate seamless interdisciplinary interaction resulting in more widespread professional input to the architect’s design while still in progress.

6.3.5 Challenges facing adoption of HBIM in adaptive reuse projects

Despite the benefits accrued through application of HBIM, adoption still faces a challenge. Procuring the BIM software comes at a cost, and sometimes involves retraining employees. There is also a general lack of awareness on HBIM tools and processes due to lack of a HBIM standard. This calls for more training on HBIM and development of a HBIM standard that is contextualized to the local AEC industry.

6.3.6 Evaluation of HBIM in Adaptive Reuse

The researched and proven abilities of BIM in the AEC industry at large, and the observed abilities of HBIM in choice preservation and adaptive reuse projects globally, have persuaded the author that HBIM may offer significant contribution to the practice of adaptive reuse in Kenya. A study of the level of HBIM adoption in the country, is needful yet lacking. This gap is even greater with respect to adaptive reuse. The international precedent study and the local case studies above have shown different levels of adoption of HBIM in different kinds of projects (i.e., a restoration and a reproduction project respectively), and the varying extents of positive and negative impact to the success of the process adopted. Both of these projects share most parts of their workflow, and the activities involved, with typical adaptive reuse projects. A study of them has there been productive in assessing the potential for adoption of HBIM in adaptive reuse processes, the potential benefits and challenges, and the common barriers against this adoption. The study of Peshceria di Giulio has highlighted

the potential of HBIM particularly in enhancing documentation, simulations and analysis, visualization and management of projects to facilitate efficient delivery of accurate and timely architectural solutions. The study of All-Saints has argued for the significant success noted in activities that are typical to adaptive reuse, even when manual tools are employed. Consequently, the case studies argue for the hybrid adoption of manual and HBIM tools in the adaptive reuse process. However,the noted challenge of clashes between different models argues for the need for the implementation of an integrated project delivery approach. This is based on the collaborative manipulation of a federated model in real time.

6.4Conclusion

In conclusion, a nexus between the practice of adaptive reuse and heritage-BIM can be created by the adoption of HBIM tools and employing the IPD workflow. This will result in gains of time, costs and accuracy in the various tasks involved in a typical adaptive reuse process. Tasks which appear to have a high potential for gaining from HBIM tools and processes are documentation, simulations and analysis, visualization and management of projects to facilitate efficient delivery of accurate and timely architectural solutions. However, many manual tools are still useful in performing some of these tasks hence should not be replaced but complimented by the HBIM tools.

6.5Limitations and recommendations

The extent of research was limited to that which could be performed within the schooldefined period. This limitation impacted the number of questionnaire responses since time could not allow for physical interviews. Repeat interviews were also not possible. Further, the researcher was constrained to limit himself to only architects, though HBIM service providers and building owners were key stakeholders also. Moreover, several architectural drawings for the local case study could not be procured in time due to lengthy access procedures. Furthermore, the study was limited to that which could be performed with the human, financial and logistical resources available. While the research would have been more informative if the different HBIM technologies were tested, the researcher was limited in his access of them.

The focal point of this study was investigating and discussing the nexus between HBIM adoption and adaptive reuse. However, it did not test for the frequency of use of the HBIM technologies, or the willingness of professionals to adopt them. Moreover, the response rate was generally low hence cannot be taken as an entirely accurate

representation of the level of adoption of HBIM across the profession. Consequently, it is advisable for researchers interested in the level of HBIM adoption in adaptive reuse to use the methodology and findings of this thesis as base for further research with a larger response rate

REFERENCES

Addison, A. C. (2007). Base Recording: Gathering Information. In R. Eppich (Ed.), Recording, Documentation, and Information Management for the Conservation of Heritage Places (pp. 13–44). The Getty Conservation Institute.

Arun, G. (2007). Data Management: Analyzing Information. In R. Eppich (Ed.), Recording, Documentation, and Information Management for the Conservation of Heritage Places (pp. 73

104). The Getty Conservation Institute.

Barazzetti, L., Banfi, F., Brumana, R., & Previtali, M. (2015). Creation of parametric BIM objects from point clouds using NURBS. Photogramm. Rec, 339

362.

Bartlett, C. (2014). The Design of The Great Pyramid of Khufu. Nexus Network Journal, 16(2), 299–311. https://doi.org/10.1007/s00004-014-0193-9

Bruno, N., & Roncella, R. (2019). HBIM for Conservation: A New Proposal for Information Modeling.

Cheng, Y., Kuo, C., & Mou, C. (2021). Ontology-Based HBIM for Historic Buildings with Traditional Woodwork in Taiwan. Journal of Civil Engineering and Management, 27(1), 27–44.

Chikwanda, G. (2007). Base Recording: Gathering Information. In R. Eppich (Ed.), Recording, Documentation, and Information Management for the Conservation of Heritage Places (pp. 13–44). The Getty Conservation Institute.

Crosby, A. (2007). Base Recording: Gathering Information. In R. Eppich (Ed.), Recording, Documentation, and Information Management for the Conservation of Heritage Places (pp. 13–44). The Getty Conservation Institute.

Dallas, R. (2007). Introduction. In R. Eppich (Ed.), Recording, Documentation, and Information Management for the Conservation of Heritage Places (pp. 5–12). The Getty Conservation Institute.

Early Agriculture And The Rise Of Civilization. (2021). In Encyclopedia.com

Eppich, R., Chabbi, A., & Getty Conservation Institute. (2007). Recording, Documentation and Information Management for the Conservation of Heritage Places: Illustrated Examples. Getty Conservation Institute.

Ewart, I. J., & Zuecco, V. (2019). Heritage Building Information Modelling (HBIM): A Review of Published Case Studies. 35th CIB W78 2018 International Conference: IT in Design, Construction, and Management, 35–41.

Fassi, F., Achille, C., Mandelli, A., Rechichi, F., & Parri, S. (2015). A new idea of BIM system for visualization, web sharing and using huge complex 3D models for facility management. Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci., 359–366.

GoK. (2012). National Museums and Heritage Act (2006). Laws of Kenya, Cap 216.

Grimmer, A. E., & Weeks, K. D. (2010). New Exterior Additions to Historic Buildings: Preservation Concerns. In Preservation Brief 14.

ICOMOS, A. (2013). The Burra Charter: The Australia ICOMOS Charter for Places of Cultural Significance.

Jacobs, J. (1961). The Death and Life of Great American Cities. Random House.

Lang, K. R., & Whitney, C. A. (1991). Wanderers in Space: Exploration and Discovery in the Solar System.

Latham, D. (1999). Creative re-use: Working with the building. Journal of Architectural Conservation, 5(2), 7–23. https://doi.org/10.1080/13556207.1999.10785240

Mısırlısoy, D. (2016). Contemporary extensions and heritage buildings: A design methodology. LAP LAMBERT Academic Publishing.

Mısırlısoy, D. (2017). New Designs in Historic Context : Starchitecture vs Architectural Conservation Principles. Civil Engineering and Architecture, 5(6), 207–214. https://doi.org/10.13189/cea.2017.050602

Murphy, M., Mcgovern, E., & Pavia, S. (2009). Historic building information modelling ( HBIM ). 27(4), 311–327. https://doi.org/10.1108/02630800910985108

Ogleby, C. (2007). Data Management: Analyzing Information. In R. Eppich (Ed.), Recording, Documentation, and Information Management for the Conservation of Heritage Places (pp. 73–104). The Getty Conservation Institute.

OmniClass (TM) Construction Classification System. (n.d.). Retrieved July 23, 2019, from https://www.csiresources.org/standards/%0Aomniclass

Ragheb, A. (2011). Towards Environmental Profiling for Office Buildings Using Life Cycle Assessment (LCA)

Riegl, A. (1903). “Der Moderne Denkmalkultus: Sein Wesen und seine Entstehung.” Gesammelte Aufsätze, 144–193.

Ruskin, J. (1849). The Lamp of Memory

Sear, F. (1982a). Roman Architects, Building Techniques and Materials. In Roman Architecture (1st ed., p. 17).

Sear, F. (1982b). Roman Building Types. In Roman Architecture

Semes, S. W. (2007). Part One: “‘Differientated’ and ‘Compatiable’: Four Strategies for Additions to Historic Settings.” Sense of Place: Design Guidelines for New Construction in Historic Districts.

Semes, S. W. (2009). Differentiated and Compatible. Traditional Building, February.

Sikka, S. (2007). Base Recording: Gathering Information. In R. Eppich (Ed.), Recording, Documentation, and Information Management for the Conservation of Heritage Places (pp. 13–44). The Getty Conservation Institute.

Swenson, A., & Chang, P.-C. (2020). Construction. In Encyclopedia Britannica.

The Constructions Specification Institute. (2010). CSI UniFormat (TM) 2010 classification

The Secretary of the Interior’s Standards for the Treatment of Historic Properties. (1995).

Tommasi, C., Achille, C., & Fassi, F. (2016). From point cloud to BIM: A modelling challenge in the Cultural Heritage field. Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci., 429–436.

Torres, Z. N. G. (2009). Historic Buildings and Contemporary Additions: The Elements of a Cohesive Design Relationship

Van Tilburg, J. A., Pakarati, C. A., & Hom, A. (2007). Base Recording: Gathering Information. In R. Eppich (Ed.), Recording, Documentation, and Information Management for the Conservation of Heritage Places (pp. 13–44). The Getty Conservation Institute.

Viollet-le-Duc, E. E. (1854). Dictionnaire Raisonné de l’Architecture Française du Xie Au Xvie Siècle

Wandera, N. W. (2019). Adaptive Reuse of Buildings for Heritage Conservation: A Case of Kisumu City. University of