Assessment of Selected English Colonial Heritage Features for Sustainable Conservation in Kaduna Metropolis, Nigeria

Heritage conservation is an avenue for human sociocultural value sustenance. This book chapter establishes the significant heritage values, determines the relative influential index of deterioration as well as assesses the suitable sustainable heritage conservation options within colonial town of Kaduna. Questionnaires were processed based on purposive sampling and administering 80 of them to building industry and allied heritage professionals, having 50 questionnaires that is about 62% dully filled and returned for analysis. The research instrument was validated using face and content analysis, while the Cronbach’s alpha reliability test value for internal consistency of questionnaire instrument was established as being greater than 0.7. The study findings affirmed that historic factors were most significant in value of heritage, while government neglect is the most significant cause of deterioration. Correspondingly, heritage value criteria were considered as more significant than heritage deterioration agents in ascertaining the preferred sustainable conservation options. Conclusively, heritage conservation can be achievable by aptly establishing its significant value and undertaking timely deterioration assessment. This study recommended fashioning of conservation policy model by experts that will guide government agencies on conservation programs for sustainable heritages. The model will encourage local community sociocultural and economic partnership for tourism development. This study examined experts’ judgement of perceptual values of key colonial structures in Kaduna metropolis which include offices, residences and monuments. The study takes into consideration key approaches to sustainable heritage conservation which includes preservation, repairs, maintenance, restoration, treatment, dismantling and relocation as well as reconstruction in consultation with users and local communities Deterioration agents were associated with government neglect; tear and wear; poor level of awareness; vandalism; thermal, biological and condensational activities; mechanical


Introduction
In most parts of the world, colonialism left behind footprints of legacies and heritages with amazing lessons and inspirations to learn and draw from. Although it can be argued that Africa had always had her indigenous knowledge that are mostly anchored on what is considered as 'intangible heritages' [1], colonial heritage features have however had great influence on the social, economic, political and cultural development of most African nations. Ever since then most scholars have tended to model African nations' sociocultural landscapes including the explanation for their causes along the heritages left behind by their colonial masters.
Britain, for example, has a number of bodies and commissions that ensure the preservation of heritage resources and sites. As part of environmental assessment in Britain, developers are mandated to investigate whether or not their development will affect any heritage site, ancient monument or listed buildings [2]. Analysts have often than not based their arguments on the logic that the landscape of a place gives an insight of what has happened there over a given time frame. According to Peter Benton, a principal preservation planner and a member of the American Institute of Architects, he argued that by looking at the geology and landscape of communities and other materials around, you can piece together the history of a place [3]. It is these perceptions that have caused governments across the world to initiate policies and programmes aim at preserving heritage resources and sites.
The heritage of a place, be it material or immaterial and whether indigenous or foreign, is highly valued because it provides invaluable insights into the changing dynamics [4]. In Britain, these bodies and commissions include the English Heritage, National Trust, Historic Buildings and Monuments Commission and English Nature. In many cities of the countries that were colonised, a number of structures were built for administrative and economic convenience by the colonial authorities and are labelled as the memorials of their past [5].
For Nigeria, the heritage landscape is replete with several features both (temporal and in-temporal cum spiritual). In this case the major tangible structures as stated by [6] include Presbyterian Church, Calabar (1846); First storey building, Badagry, Lagos (1845); Egedege N'okaro residence, Benin (1906); and Gobirau minaret in Katsina (Habe dynasty, 250 years ago); others are Tafawa Balewa Square and the National Theatre completed in 1976 for the Festival of Arts and Culture (FESTAC) of 1977. The old secretariat building of Lagos is considered the signature tune for the English colonial/revivalist architectural heritage conservation of the late nineteen and twentieth century and currently one of the listed building in Lagos state [7] (Table 1).
There are several other unique heritage sites, buildings and monuments that abound in Nigeria worthy of careful study. Buildings, monuments and sites features are a major part of our national heritage; therefore, could serve as important tourist attractions that reaffirm the need for this study in Kaduna metropolis.
Said et al. [8] argued that post independent Africa seems to have their colonial features ignored just as the colonialists did to those of Africa's past. For heritage documentation, some activities are critical: identifying heritage values, describing them and incorporating the often conflicting principal stakeholders [9,10]. The identified heritage experts include specialists in social and economic values, tourism experts, environmentalists, historians, planners and developers [11,12]. Kaduna being the main colonial town of the Northern Nigerian Protectorate had several buildings and monuments that left their mark on the townscape [13]. The colonial heritage features left behind in Kaduna needed to be conserved as has been done in most developed countries of the world since doing so is not only important because they provide a sense of identity in a fast-changing world for future generations but also represent the past history of a nation. Between 1999 and 2006, a number of English historic buildings were lost to the several infill activities that destroyed historic sites and buildings together with their value and the information they contained in Kaduna Government Residential Areas [14]. Although not all of these could have been conserved, most of them were products of high levels of sophistications, knowledge, tradition and history that in many instances took hundreds or thousands of years to develop. The destruction of these properties in most cases came with irreversible losses of the critical heritage identity (design, specifications and construction techniques) contained in them; it would be imperative to designate some of them as being historic and thereby could enable the enactment of appropriate preservation ordinances to protect these significant buildings and monuments before a worst fate befalls them. This study examined experts' judgement of perceptual values of key colonial structures in Kaduna metropolis which include offices, residences and symbolic monuments. The study takes into consideration key approaches to sustainable heritage conservation which includes preservation, repairs, maintenance, restoration, treatment, dismantling and relocation as well as reconstruction in consultation with users and local communities [15,16]. Deterioration agents were associated with government neglect; tear and wear; poor level of awareness; vandalism; chemical, thermal, biological and condensational activities; and mechanical and electromagnetic solar effects [9,12]. However, since value is an underlying rationale for heritage conservation, value perception was restricted to experts in arts history, archaeologist, architects and others who have been identified as critical fresh stakeholders or constituents [17].
Apart from the empirical need to conserve heritage buildings and monuments in Kaduna, studies of colonial features have not had their fair share in the post independent African heritage studies. The need to increase the city's building and monument profile in the country's stock of listed buildings has received attention in recent times. Zubairu et al. [18] opined that as historic as Kaduna metropolis is in the community of historic cities in Nigeria and Africa as a whole, only Lord Frederick Lugard Bridge in Kaduna was a listed structure for Nigeria. This leaves much to be desired considering the vast heritage features that abound in Kaduna as the main colonial town of Northern Nigeria [13]. All these realities call for concerted efforts to improve the image of heritage structures in Nigeria and Kaduna in particular including the necessary tools to make it work from the perspective of Nigerian realities.
The lack of listed building and monument heritage particularly colonial features in Kaduna metropolis is of great concern. Therefore, value perception assessment of significant historic buildings and monuments is therefore a rational step towards sustainable conservation of these properties. The study similarly examined and tackled the fundamental issue of methodological challenges associated with value assessment of historic buildings and monuments as well as the need to contextualise the heritage conservation and tourism need of Kaduna metropolis as a colonial city.

Review of relevant literature
A further review of relevant variables for this study is undertaken to aid in contextualising the specific variables of the study.

Conservation of heritage
Heritage and conservation are interrelated in a way, as heritage is considered an expression of the sociocultural value product of a people, its conservation ensures the bequeathal to posterity. The research team [19] stated that conservation serves as a medium for architectural and historical heritage revitalisation. Meanwhile, to revitalise the heritages, it is significant to identify and assess the various relationships involved. In this study the relationships are with respect to heritage value, deterioration and their prospect for sustenance. Similarly, [20] contended that conserving urban heritage is growing with better funding; however, he argued that the partial perception of heritage conservation equally has varied scopes. On the other hand, [15] contended that conservation is categorised based on the various physical buildings and spatial relationship. [15,16] did affirmed that various approaches for sustainable heritage conservation are applicable and include preservation, repairs, maintenance, restoration, treatment, dismantling and relocation as well as reconstruction in consultation with users and local communities. Likewise, [21] maintained that cultural heritage features are made up of buildings, monuments, gardens, cemeteries, landscape and archaeological sites.

Conservation and sustainability issues
Conservation of heritage building or site is a process of catering for a place so that it can retain its significant historical, architectural, aesthetic and cultural value. Similarly, Gro Harlem Brundtland Commission Report 'our Common Future' in 1987 defined sustainable development that is succinctly paraphrased in [22] as '... meeting the needs of present generation without jeopardizing the ability of future generation to meet their needs'; [23] further reinforced the argument that conservation relates directly to sustainability, while [24] also averred that sustainability is centred around economic, social and environmental parameters.
Studies by [25,12] as well as [26] variously argued that heritage conservation should incorporate public interest, sociocultural values, as well as environmental parameters. Often the terms sustainable development, conservation and sustainability emphasise connection amongst social equity, economic production and environmental quality, which should be adaptable to heritage setting. Kaduna as a main Gbagyi settlement was transformed into a major town for all Northerners that housed its colonial-built treasures. Kaduna metropolis was initially settled by mainly colonialist, their dependents, workers from within West Africa and Southern Nigeria Protectorate [5]. Towards entrenching a functional colonial system, structures were built that include private residences, offices, services and symbolic structures as bridges and entrance gates which form the fulcrum of this particular study.

Heritage buildings and monuments
The International Council on Monuments and Sites (ICOMOS) Venice Charter of 1964 adopted during the 2nd International Congress of Architects and Technicians of Historic Monuments made definite decisions on heritage. During the congress it was advocated that heritage should maintain buildings and monuments to ensure social usefulness, within original scale and historical setting [27,28]. Furthermore, ICOMOS Charter of 2003, at Victoria Falls, Zimbabwe, argued that structures of architectural heritage lay confronts for restorative finding in terms of nature and history suitable for the cultural context. During the 14th general assembly at Zimbabwe in 2003, they also establish the principles that cover general criteria, research, diagnosis, remedial measures and controls. Specifically, the principles' general criteria cover conservation, reinforcement and restoration; others are value and authenticity, integrity, functional changes, peculiarity of heritage structure and the underlining concept of no action to be taken until benefits can be ascertained proactively. EngleHardt [25] argued that built heritage provides the physical space for the nonphysical expressions of culture and constitutes one of the most varied, complex and eloquent manifestations of tangible cultural heritage. Here then is the essence of this particular study towards conserving Kaduna colonial heritage features with specific emphasis on its buildings and monuments.

Heritage values and deterioration
For any heritage to be conserved for control or minimised decay or deterioration, there is the need to establish its value to the community or society at large. Morgan et al. [29] opined that value is in general the same as meaning or in valuation, meaning confirmed and enhanced with emphasis. Value is here considered as the result of brain conversion of direct experience (immediate perception) into meaning and actionable truth (a secondary judgement or conception). The Allen Consulting Group [30] contended that historic heritage features in Australia are priceless in terms of their value. It is here believed that there is value creation for architectural designs and literature through heritage conservation. This was further elaborated by [31] as they considered heritage value as mainly based on use state rather than the exchange rate. Heritage value in this context has to do with historical, architectural, political, sociocultural, technological and economic value of the heritage features within Kaduna metropolis.
Building deterioration on the other hand has to do with its material component or finishes that do not meet its initially acceptable performance criterion. Mydin et al. [12] stated that often buildings suffer from defects that range from cracks, water penetration or human activity-based deterioration. Factors considered as responsible for deterioration of heritage buildings are broadly classified as natural (environmental) and man-made (social) [9,12,32]. It is these key issues that underlay the concern of this paper and have been articulated for enhanced perception and applicability.
Urban and Architectural Heritage Conservation within Sustainability 8

Research methodology
The study heritage features are mainly along Ali Akilu way through Ahmadu Bello way to Junction road as well as Independence way linking back to Junction road. The choice of these areas/routes was due to their historical place as the core segment of the town during colonial era. These routes also harbour virtually all the colonial administrative features of the 1900 to 1960 period in Kaduna metropolis. Stratified purposive sampling of building heritage and monuments within Kaduna metropolis was made. With the aid of convenience sampling method, a sample design of selected heritage and allied professionals was made [33]. A total of eighty (80) questionnaires were administered to various respondents in the built environment and experts in heritage and conservation within Kaduna metropolis. Fifty (50) of the questionnaires were duly filled and returned with the help of four research assistants, while three (3) were returned but not duly filled thus were considered invalid. This will aid in ascertaining the respondent perception in respect to value, deterioration and suitable sustainable conservation.
Feedback on the questionnaire was provided on its appropriateness as well as information presented (face and content validity test) to ascertain whether the main issues were effectively communicated [34]. The questionnaire instrument employed used internal consistency reliability to assess the results across the different items [35]. The instrument was shown to have value range of 0.788 for deterioration, 0.876 for sustainable conservation options and 0.903 for heritage value using Cronbach's alpha reliability test. Therefore, since the Cronbach's alpha values are all greater than 0.7, it shows that the instrument is reliable for obtaining information from respondents [24,36].

Results and analysis
The colonial administration core buildings identified and used in this study are Hassan Katsina (State) House, Lugard Hall building, Lord Lugard Residence/Water Tower, Secretariat Complex and Magajin Gari. The monuments on the other hand are the Northern Entrance City Obelisk, Kaduna Railway Junction Steel Bridge and the Lord Lugard Bridge.

Selected heritage buildings and monuments in Kaduna metropolis
Below is the description of these heritage buildings and monuments stating their basic features with pictorial illustrations.
Hassan Katsina State House Complex, along Kawo way, was an administrative office building used since the colonial period and currently serves as the office of His Excellency the Deputy Governor of Kaduna state. The feature within the complex as you enter the main gate is the banquet hall that serves as the state for major occasions (Figure 1). Its design is an integration of the traditional Hausa Architecture and utilisation of colonial-styled materials and skill craftsmanship for its design and construction.
Kaduna Commemorative Entrance Obelisk is mainly made up of well-carved stoneworks at the Northern entrance of the city just by the entrance of the old Nigerian Defence Academy (NDA). It was erected to commemorate the visit of Her Royal Majesty Queen Elizabeth and His Highness the Duke of Edinburgh to Kaduna in February, 1956 (Figure 2). Recently it was demolished and relocated to allow for the expansion of the major road artery to the town from the northern axis from 4 to 6 lanes. The initial concept was maintained, and the old stones were also utilised with additional stoneworks crafted in similar fashion as those of the initial commemorative entrance monument.
Lord Lugard Hall is one of the major symbols of the great history of Kaduna town from colonial times to post independence. It served as the house of chiefs and later translated to the present Kaduna State legislators House of Assembly (Figure 3a  and b). It is strategically located just off Ali Akilu road along the old Coronation road presently Independence way that lings to the State Secretariat Complex.
Lord Lugard Residence/Water Tower is located off Coronation Avenue present day Independence way just adjacent the Lugard Hall; it is currently vandalised and laid bare on the pretence of government rehabilitating the historic residence. The house is a duplex situated on an expand of land that has been subject to several litigation towards being excised (Figure 4a and b). The last administration in the state gave out the contract for the rehabilitation of the Lugard residence; unfortunately it became a pretext for vandalised very antique materials available in the building. This was more serious with respect to doors and windows including ceilings and the roof structure/lining. Recently, the current government has commissioned another set of consultants to produce a proposal towards restoration and adaptation for museum with prospect as a major tourist feature for the town. Just beside the residence is the Water Tower that is used to serve the Lugard complex and often used as a watch tower during the early days of Kaduna city development shown in Figure 4c. State Secretariat Complex along the Independence way is a collection of very interesting and unique colonial heritage buildings that housed the Civil Service Ministries then and now. The ministries currently being housed include Education, Economic Planning and Finance (Figure 5a and b). Figure 6 is showing the ministry of Justice and Ministry of Water Resources. Across the road directly opposite these ministerial complexes are two other ministries. They are the Ministry of Health and Women Affairs in Figure 7a and b. Most of the buildings have undergone some form of renovation, particularly the replacement of roofing structure and linings. The main building structure is still intact and wonderfully preserved in its initially built form.
The Magajin Gari Complex is made up of the Local Government Secretariat and the Sharia courts (Figure 8a and b). It was formally the centre for the Northern Nigeria Native Authority administration. The architecture is distinctively made up   of traditional Hausa form, domes, arches, decorative motifs and varied pinnacles (Zankwaye). These pinnacles were an extension of the parapet walls in a traditional building and are basically symbolic manifestation of aesthetic elegance in traditional architecture. These became so because they have lost their initial function as stake around which master builders dangle rope ladder for climbing roof or plastering of building facades.
Lugard Bridge is a very important steel bridge historical monument that was first constructed in 1904 at Zungeru but brought into Kaduna when the colonial master relocated the Northern protectorate headquarters to Kaduna (Figure 9a and b). It is      the two parts of the city made up of concrete bridge as you journey daily from one end of town to the other (Figure 10a and b). Table 2 displays RII values of Kaduna heritage building and monument value significance; it was suggested that heritage buildings were ranked the first with significant influence on the heritage value, followed by heritage monuments. Similarly, historical factors were ranked the highest variable under heritage building and monument categorisation, being critical variable that influence the heritage value of heritage building and monuments and economic factors as being the least significantly valued by respondents. Table 3 revealed that government neglect being ranked the highest is considered the most significant agent that causes building and monument deterioration, followed by tear and wear of building and monument deterioration; then lack of public awareness; vandalism; chemical, thermal, biological and condensational activities; and mechanical and electromagnetic solar effects. The least agents that significantly influence the deterioration of buildings and monuments are considered as electromagnetic solar action.     considering the paucity of funds, conservation of heritage is not given appropriate consideration based on government scale of preference. On the other hand, the minimal deterioration caused by electromagnetic and solar effect on monuments could be attributed to the nature of most of the feature design and specifications. In the design there was extensive provision of veranda, corridors and recesses on most openings; as well as high-quality and durable materials were specified and used during construction. While the government is considered the most critical culprit in heritage deterioration, the other side of the challenge will be that most other stakeholders may stand aloof without bringing to bear their expertise as well as communal consideration in conserving the features. 4. The option for heritage building conservation has the highest reflective influence index (75.4) since most respondents are more conversant and interact with the buildings more frequently than they do with monuments (72.2). In fact, most monuments within the study area are either abandoned or have no active significance in the daily life of the city dwellers, therefore making them seem less attractive for conserving than the buildings that are currently being used as offices and other administrative accommodation. The building heritage maintenance and treatment (renovation) was most significant at 84.9 option for conservation as most of the buildings materials are dying and rarely in used. Currently some of them are being demolished and redeveloped using less responsive design and specification options, hence the preference of professional for this option. The Monuments most preferred option for conservation was considered as preservation (maintaining of the fabric) at 79.6 since such materials are mostly not available or being used in such construction currently. Thus the significance of preserving the heritage features for posterity is towards serving as major tourist site now and in the future. Reconstruction of buildings was considered the least option for conservation and adaptation (change of function) for monument as such action could easily undermine the significance of the heritage features and their place as historical legacies. The respondents' perception of the building value is core to any conservation work than the features' level of deterioration. This further affirms the place of value in heritage conservation as variously argued (Mydi, Ramli and Awang, 2012).

Conclusion and recommendations
In conclusion, the study was able to ascertain the place of heritage buildings and monuments for colonial Kaduna metropolis. This was done through integrating the key heritage value indicators and deterioration agents to determine most suitably significant heritage sustainable conservation options. By this, the study set in motion an evolving trend of value rating and deterioration assessment model. This model if adopted can enable forecasting suitable conservation options for enhanced tourism activities as well as points direction for prospective architecturally and historically significant developments. Here from further detail, © 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Author details
Marcus Balah Ryal-Net*, Bogda Prucnal-Ogunsote and Erekpitan Omoikhefe Ola-Adisa Department of Architecture, Faculty of Environmental Sciences, University of Jos, Nigeria *Address all correspondence to: ryalnetmarcus@gmail.com studies could be undertaken to ascertain specific heritage building and monument value as well as their status of deterioration for the various stakeholders' appropriate action. More purposeful sustainable heritage buildings and monuments are attainable by careful conservation measures on each heritage structure depending on its requisite need.
Based on study finding, the following recommendations are hereby presented as follows: 1. Heritage experts are to evolve acceptable value significance factors for heritage buildings and monuments in Kaduna metropolis for colonial buildings.
2. Government agencies occupying heritage buildings should be mandated to produce and adhere to professionally developed maintenance manual for all buildings and monuments with the experts' inputs.
3. Historic relevance of each monument should be periodically highlighted to further enlighten people on their significance so that heritage monuments conservation can be brought to the fore.
4. Adopt a comprehensive conservation template for all heritage features as an integral metropolis tourism package for possible generation of financial resources that can be used for conservational activities.
Finally, this submission supposes that a more sustainable heritage conservation can be attained and maintained with periodic value reassessment as well as establishment of actual deterioration status of each feature for the benefit of posterity.