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Project – The Effect of Building Material Costs on Housing Project Completion in Nigeria: A Case Study of Selected Construction Projects in Lagos State

CHAPTER ONE

INTRODUCTION

1.1 Background to the Study

The construction industry plays an important role in national economic development through the provision of residential buildings, commercial facilities, transportation infrastructure and other essential structures. Housing construction, in particular, contributes to economic growth by creating employment opportunities, stimulating investment in building materials and supporting activities across the manufacturing, transportation and professional services sectors. However, the successful delivery of housing projects depends on several factors, including adequate financing, effective project management, availability of skilled labour, appropriate construction technology and the affordability of building materials. Among these factors, the cost of building materials is particularly important because materials constitute a substantial component of total construction expenditure. Fluctuations in the prices of cement, reinforcement bars, sand, granite, roofing sheets, timber, blocks and finishing materials can significantly affect project budgets and implementation schedules. Ofori (2000) explains that the performance of the construction industry is closely connected to the wider economic environment and the availability of resources required for project execution. Similarly, the World Bank (2020) identifies construction costs, access to finance and institutional conditions as important considerations in the provision of adequate and affordable housing. Therefore, understanding how building material costs influence housing project completion is necessary for improving construction performance and addressing housing delivery challenges in Nigeria.

Building materials are essential inputs in the construction process, and their prices directly influence the financial requirements of housing projects. The cost of materials is determined by several factors, including production expenses, transportation charges, importation costs, exchange-rate movements, energy prices, government policies, market demand and the availability of raw materials. In Nigeria, the production and distribution of construction materials are affected by the cost of electricity, fuel, transportation and industrial operations. Materials such as cement, steel, aluminium products, tiles and electrical fittings may also experience price changes due to fluctuations in production and supply conditions. These changes can create difficulties for contractors who prepare project estimates based on prevailing market prices but later encounter higher costs during construction. The International Labour Organization (ILO, 2015) identifies economic and institutional conditions as important influences on productivity and employment in the construction sector. Likewise, the National Bureau of Statistics (NBS, 2023) provides evidence of the importance of monitoring changes in prices across different sectors of the Nigerian economy. When the prices of essential construction materials increase beyond the amounts provided in project budgets, contractors and developers may face financial pressure, which can affect procurement decisions, construction activities and completion timelines.

The relationship between building material costs and project completion is also reflected in the financial planning and cost-control processes adopted by construction firms. Before a housing project begins, developers and contractors usually prepare estimates covering materials, labour, equipment, transportation, professional services and other project expenses. These estimates guide financial commitments, procurement arrangements and construction schedules. However, where material prices increase unexpectedly, the original project budget may become inadequate. Contractors may respond by requesting additional funds, reducing the quantity or quality of materials, negotiating new contract terms, slowing down construction activities or temporarily suspending work. In some situations, clients may be unable to provide additional funds, resulting in delays or abandonment of projects. Aibinu and Jagboro (2002) identify time overruns as a significant problem in Nigerian construction projects and explain that delays can arise from factors associated with project execution and management. Assaf and Al-Hejji (2006) similarly identify financial and contractual issues among the factors contributing to construction delays. These findings suggest that the financial implications of material price increases can affect the ability of contractors to complete housing projects within the agreed period and budget.

In Nigeria, the challenge of rising building material costs has become an important issue in housing development because of the country’s dependence on a combination of locally produced and imported construction inputs. Although materials such as sand, laterite, granite, blocks and some cement products are available locally, their prices are still influenced by production costs, transportation, energy supply and market conditions. Other materials and components may be affected by foreign exchange fluctuations and international supply-chain disruptions. These conditions can create uncertainty for contractors and property developers, especially when projects require materials to be purchased over several months or years. The National Bureau of Statistics (NBS, 2023) provides economic data that can be used to understand movements in prices and broader inflationary pressures in Nigeria. The Central Bank of Nigeria (CBN, 2023) also identifies exchange-rate conditions and inflation as important macroeconomic factors affecting business operations and investment decisions. Consequently, the rising or unstable cost of construction materials may increase the financial burden of housing development and make it more difficult for contractors to maintain the original project budget and completion schedule.

The problem is particularly relevant to Lagos State because of its high demand for residential accommodation, continuous urban expansion and substantial construction activities. Lagos is one of Nigeria’s major commercial and population centres, attracting individuals, businesses and investors from different parts of the country. This demand has encouraged the development of private residential estates, apartment buildings, mass housing schemes and other forms of housing projects. However, the high cost of land, construction materials, labour and infrastructure can make residential development financially demanding. The Lagos State Government (2014), through its development planning framework, recognises the importance of infrastructure, urban development and housing provision in the state’s growth. Nevertheless, the availability of suitable land and adequate funding does not automatically guarantee successful project delivery, particularly where construction costs continue to change during implementation. The World Bank (2020) also emphasises that housing affordability and delivery are influenced by the cost of land, construction inputs, financing and the wider regulatory environment. These conditions make Lagos State an appropriate setting for investigating the influence of building material costs on housing project completion.

Housing project completion involves delivering a building according to its approved design, specifications, budget and agreed construction period. It requires the coordination of materials, labour, equipment, finance, contractors, consultants and clients throughout the different stages of construction. When building material costs rise significantly, the financial arrangements made at the beginning of a project may no longer be sufficient to sustain construction activities. This can result in delayed procurement, interruptions in work, variations in project specifications and disagreements between contractors and clients. Doloi et al. (2012) identify poor planning, financial difficulties, contractor-related problems and other project management issues as important contributors to construction delays. Aibinu and Jagboro (2002) also demonstrate that delays have financial and operational consequences for construction projects in Nigeria. Although delays may arise from several causes, material cost increases can intensify existing financial and management difficulties. Therefore, examining the effect of building material costs on project completion requires attention to how price fluctuations affect construction budgets, procurement arrangements, project schedules and the financial capacity of project stakeholders.

Despite the importance of housing development to social welfare and economic growth, the increasing cost of construction materials presents a challenge to the timely and successful completion of residential projects. Some developers may experience difficulties in maintaining project budgets when material prices rise after construction has commenced, while contractors may struggle to meet contractual obligations where the original contract sum becomes inadequate. Smaller construction firms and individual property developers may be particularly exposed because they may have limited access to additional finance or alternative procurement arrangements. Furthermore, inadequate cost forecasting, weak procurement planning and limited contingency provisions may increase the effects of material price changes. The Royal Institution of Chartered Surveyors (RICS, 2021) highlights the importance of cost management, risk assessment and informed decision-making in construction project delivery. Similarly, the Project Management Institute (PMI, 2021) identifies planning, budgeting, risk management and stakeholder coordination as essential elements of successful project performance. It is against this background that this study examines the effect of building material costs on housing project completion in Nigeria, using selected construction projects in Lagos State as a case study.

1.2 Statement of the Problem

The cost of building materials is one of the major financial considerations in housing construction, as materials such as cement, reinforcement bars, sand, granite, blocks, roofing sheets, timber and finishing products are required at different stages of project implementation. In Nigeria, fluctuations in the prices of these materials can make it difficult for contractors and developers to maintain the budgets prepared before construction begins. When material prices increase during project execution, the original contract sum may become inadequate to cover the remaining construction activities. This situation can lead to additional financial demands, delays in procurement, interruptions in construction work and difficulties in meeting agreed completion dates. Aibinu and Jagboro (2002) identify construction delays as a significant problem in Nigeria, while Assaf and Al-Hejji (2006) establish that financial and contractual factors can contribute to delays in construction projects. The central problem, therefore, is that unstable or increasing building material costs may undermine the financial capacity of project stakeholders and make the completion of housing projects within approved budgets and schedules increasingly difficult.

Another problem is the difficulty contractors and developers face in preparing accurate construction estimates in an environment where material prices can change during project implementation. Construction estimates are generally based on prevailing market prices, expected quantities and anticipated project duration. However, where prices increase unexpectedly, contractors may have to revise their budgets, negotiate additional payments or seek alternative sources of finance. In situations where clients cannot provide additional funds, construction activities may slow down or stop completely. This challenge can be more serious for small and medium-sized construction firms that have limited financial reserves and may find it difficult to absorb unexpected increases in project expenditure. Doloi et al. (2012) identify inadequate planning, financial constraints and project management weaknesses as important causes of construction delays. The problem is therefore not limited to the increase in material prices alone but also concerns the ability of contractors and developers to anticipate, manage and respond to cost variations throughout the construction process.

In Lagos State, the challenge is particularly important because of the continuous demand for residential accommodation and the high level of construction activities across the state. Developers undertaking residential projects may encounter rising costs associated with cement, steel, roofing materials, electrical fittings, plumbing materials and other construction inputs. Where these increases are not adequately anticipated, they may affect procurement schedules, construction quality, project scope and the ability to complete buildings within the expected period. In some cases, developers may reduce the quality of specified materials, postpone certain stages of construction or suspend projects while searching for additional funds. The World Bank (2020) identifies construction costs and access to housing finance as important factors influencing housing provision and affordability. Aibinu and Jagboro (2002) also demonstrate the consequences of construction delays in the Nigerian environment. However, there is a need to examine how these material cost challenges affect the completion of selected housing projects specifically within Lagos State.

Furthermore, although construction cost management and project delivery have received attention in previous studies, there remains a need for project-based evidence on the relationship between building material costs and housing project completion in Lagos State. The effect of material price increases may differ according to project size, procurement arrangements, contract type, duration, availability of finance and the financial capacity of contractors and clients. Without examining these factors, it may be difficult to identify the extent to which building material costs contribute to project delays, budget overruns, changes in construction specifications and incomplete housing projects. The Project Management Institute (PMI, 2021) emphasises the importance of cost planning, risk management and monitoring in achieving project objectives. Accordingly, this study seeks to investigate the effect of building material costs on housing project completion in Nigeria, with particular attention to selected construction projects in Lagos State.

1.3 Aim and Objectives of the Study

The aim of this study is to examine the effect of building material costs on housing project completion in Nigeria, using selected construction projects in Lagos State as a case study.

The specific objectives are to:

Examine the major factors responsible for changes in building material costs in selected housing construction projects in Lagos State.
Assess the effect of building material cost increases on the construction budgets of selected housing projects in Lagos State.
Investigate the influence of building material costs on the timely completion of selected housing projects in Lagos State.
Examine the strategies adopted by contractors and developers to manage building material cost variations and improve housing project completion in Lagos State.

1.4 Research Questions

The following research questions will guide the study:

What are the major factors responsible for changes in building material costs in selected housing construction projects in Lagos State?
What is the effect of building material cost increases on the construction budgets of selected housing projects in Lagos State?
How do building material costs influence the timely completion of selected housing projects in Lagos State?
What strategies are adopted by contractors and developers to manage building material cost variations and improve housing project completion in Lagos State?

1.5 Research Hypothesis

The following null hypothesis will be tested in the study:

H₀: Building material costs have no significant effect on the completion of selected housing construction projects in Lagos State.

1.6 Significance of the Study

This study will be significant to construction companies, contractors, property developers, quantity surveyors, project managers, building material suppliers, government agencies, homeowners, students and future researchers. It will provide information on how changes in building material costs affect housing project budgets, construction schedules and successful project delivery.

Construction Companies and Contractors: The study will help construction companies and contractors understand how fluctuations in building material prices affect project execution. It will provide information that may assist them in improving cost estimation, procurement planning, budgeting and financial management. The findings may also encourage the adoption of appropriate strategies for managing unexpected increases in material prices.

Property Developers and Investors: The study will help property developers and investors understand the financial risks associated with rising construction material costs. It may assist them in making better investment decisions, preparing realistic project budgets and providing adequate financial provisions for possible cost variations during construction.

Quantity Surveyors and Cost Consultants: The findings will be useful to quantity surveyors and cost consultants in improving construction cost estimation, cost forecasting, budgeting and cost-control practices. It may also help them advise clients on appropriate contingency allowances and procurement arrangements.

Project Managers: The study will provide useful information for project managers on the relationship between material cost variations, construction schedules and project completion. It may assist them in identifying potential cost risks early and developing strategies to minimise disruptions to construction activities.

Government and Regulatory Agencies: The study may assist relevant government agencies in understanding the challenges affecting housing project delivery. Its findings may provide useful information for developing policies that encourage local production of building materials, improve construction-sector stability and promote affordable housing development.

Building Material Suppliers: The study will help suppliers understand the implications of material price changes for contractors and developers. It may encourage better supply arrangements, improved distribution systems and more predictable pricing practices.

Homeowners and Prospective Property Owners: The study will provide information on how building material costs influence the financial requirements and completion periods of residential construction projects. This may help individuals planning to build houses prepare more realistic budgets and make informed decisions about construction arrangements.

Students and Future Researchers: The study will serve as a reference for students and researchers in building technology, quantity surveying, construction management, estate management and related disciplines. It may also provide a foundation for further studies on construction cost fluctuations, housing affordability and project performance in Nigeria.

1.7 Scope of the Study

The study focuses on the effect of building material costs on housing project completion in Nigeria, using selected construction projects in Lagos State as a case study.

Geographically, the research will be restricted to selected housing construction projects within Lagos State. The study will examine the costs of major construction materials, including cement, reinforcement bars, sand, granite, blocks, roofing materials, timber, tiles, electrical fittings and plumbing materials.

In terms of content, the study will investigate the factors responsible for changes in building material costs, the effect of material cost increases on construction budgets, the influence of material costs on project completion periods and the strategies adopted by contractors and developers to manage cost variations.

The study will focus on residential construction projects and will not extend its investigation to road construction, bridges, industrial facilities or other non-residential infrastructure projects.

1.8 Limitations of the Study

The study may encounter certain limitations during the collection and analysis of data. One possible limitation is the difficulty of obtaining accurate financial records from construction companies and property developers. Some organisations may consider information relating to project budgets, material costs and financial transactions confidential and may therefore be unwilling to disclose such information.

Another limitation may be the difficulty of obtaining complete records of material prices throughout the different stages of construction. Since building material prices may change frequently, respondents may not have detailed historical records showing the exact prices paid at different periods of project implementation.

The study may also face challenges in accessing selected construction sites and obtaining information from contractors, project managers, quantity surveyors and other relevant professionals. Their availability and willingness to participate may affect the speed of data collection.

Financial and time constraints may further limit the number of construction projects that can be covered. However, the researcher will make efforts to select appropriate projects and obtain relevant information from respondents to ensure that the study achieves its objectives.

1.9 Operational Definition of Terms

Building Materials: The physical materials and components used in constructing residential buildings, including cement, sand, granite, reinforcement bars, blocks, roofing sheets, timber, tiles and finishing products.

Building Material Costs: The amount of money required to purchase and transport construction materials needed for a housing project.

Cost Fluctuation: Changes in the prices of building materials over a particular period, which may result in increases or decreases in construction expenditure.

Housing Project: A construction project undertaken for the development of residential accommodation, including houses, apartments, duplexes and residential estates.

Housing Project Completion: The successful finishing and delivery of a residential construction project in accordance with its approved specifications and agreed completion requirements.

Project Delay: A situation in which construction activities take longer than the period originally planned or agreed upon for project completion.

Cost Overrun: The situation in which the actual expenditure on a construction project exceeds the original approved or estimated budget.

Cost Estimation: The process of predicting the financial resources required to complete a construction project, including materials, labour, equipment and other expenses.

Procurement: The process of identifying, sourcing, purchasing and obtaining the materials and services required for construction activities.

Contractor: An individual or organisation engaged to undertake and complete construction work according to agreed contractual conditions.

Property Developer: An individual or organisation responsible for initiating, financing, managing or undertaking property development projects.

Construction Project Management: The process of planning, organising, coordinating, monitoring and controlling resources and activities to achieve construction project objectives.

1.10 Organisation of the Study

1.1 Background to the Study

The construction industry plays a significant role in national economic development through the provision of residential buildings, commercial facilities, public infrastructure and other essential structures. Housing construction, in particular, contributes to economic growth by creating employment opportunities, stimulating investment and supporting related industries such as cement manufacturing, steel production, transportation, furniture production and building services. However, the successful delivery of housing projects depends on several interconnected factors, including adequate financing, effective project management, availability of skilled labour, construction technology and the affordability of building materials. Building materials are particularly important because they constitute a substantial proportion of construction expenditure. Materials such as cement, reinforcement bars, sand, granite, timber, roofing sheets, blocks, tiles and electrical fittings are required at different stages of housing development. An increase in the prices of these materials can affect the financial resources required to complete a project and may create difficulties for contractors and property developers. Ofori (1990) explains that construction industry performance is closely connected to economic conditions, resource availability and the capacity of construction organisations. Similarly, Akanni, Oke and Omotilewa (2014), in their study of rising building material costs in Lagos State, identify increasing material prices as a significant concern for construction industry stakeholders. This makes the examination of building material costs important to understanding the financial and operational challenges affecting housing project completion in Nigeria.

Building materials are essential inputs in the construction process, and their prices directly influence the financial requirements of housing projects. The prices of construction materials are affected by several factors, including production costs, transportation charges, fuel prices, electricity supply, importation expenses, exchange-rate fluctuations, taxation, market demand and the availability of raw materials. In Nigeria, the production and distribution of materials such as cement, steel, aluminium products, roofing sheets and finishing materials can be affected by rising industrial operating costs and supply-chain difficulties. Even materials obtained locally may experience price increases because of transportation expenses, energy costs and market conditions. These factors create uncertainty for contractors who prepare project estimates based on prevailing market prices but may encounter substantially different prices during construction. Akanni et al. (2014) identify several economic and market-related factors influencing the rising cost of building materials in Lagos State and explain the implications for construction stakeholders. Similarly, Babalola, Aderogba and Adetunji (2022) establish that inflation affects construction costs and contributes to cost overruns in public building projects in Lagos State. Therefore, fluctuations in the prices of construction materials can increase project expenditure and make it difficult for developers and contractors to maintain their original financial plans.

The relationship between building material costs and housing project completion is closely connected to construction budgeting, cost estimation and financial management. Before construction begins, contractors and developers normally prepare estimates covering materials, labour, equipment, transportation, professional services and other project expenses. These estimates provide the financial basis for procurement, resource allocation and the scheduling of construction activities. However, when the prices of essential materials increase after the preparation of the initial estimate, the approved budget may become inadequate to meet the remaining project requirements. Contractors may consequently request additional funds, renegotiate contractual arrangements, reduce the quantity of materials purchased or postpone certain construction activities. Where additional funds are unavailable, construction work may slow down or stop temporarily. Aibinu and Jagboro (2002) investigated construction delays in Nigeria and found that delays frequently result in time and cost overruns, with significant effects on the completion cost and duration of building projects. Their findings demonstrate the importance of effective financial planning and adequate contingency provisions in construction projects. Thus, changes in building material costs can create financial pressure that affects the ability of contractors and developers to complete housing projects according to their original budgets and schedules.

In Nigeria, the challenge of rising building material costs is particularly important because the construction industry operates within an economic environment affected by inflation, exchange-rate movements, energy costs and fluctuations in the prices of locally produced and imported materials. Although materials such as sand, granite, laterite and blocks are available locally, their prices are influenced by production, extraction, processing and transportation expenses. Other construction inputs, including certain steel products, aluminium components, finishing materials and building services equipment, may be affected by importation costs and foreign exchange conditions. These circumstances can make it difficult for construction firms to predict the total cost of a project over an extended construction period. Babalola et al. (2022), in their investigation of inflation and cost overruns in Nigerian public sector construction projects, found that inflation contributed to project cost increases and other difficulties affecting building project implementation in Lagos State. Akanni et al. (2014) also examined the implications of rising building material costs in Lagos and highlighted the consequences for construction industry performance. These studies indicate that the problem of material cost increases is not simply a matter of higher purchasing prices; it also concerns the financial stability, planning capacity and implementation performance of construction projects.

The situation is particularly relevant to Lagos State because of its high demand for residential accommodation, population growth, urban expansion and continuous construction activities. Lagos is one of Nigeria’s major commercial centres and attracts individuals, businesses and investors from different parts of the country. This has encouraged the development of private residential estates, apartment buildings, duplexes, mass housing schemes and other forms of residential accommodation. However, housing development in the state involves considerable expenditure on land, construction materials, labour, transportation and infrastructure. The cost of materials can become a major challenge when developers undertake projects that require large quantities of cement, reinforcement bars, blocks, roofing materials and finishing products. Akanni et al. (2014) specifically investigated the implications of rising building material costs in Lagos State, drawing information from contractors, builders’ merchants and construction consultants. Their research establishes the relevance of material price increases to the state’s construction industry. In addition, Kadiri, Akintoye and Onabanjo (2019), in their comparative assessment of delays in public and private building projects in Lagos State, identified increases in material prices among the major causes of construction delays. This evidence makes Lagos State an appropriate setting for examining how building material costs affect the completion of selected housing construction projects.

Housing project completion involves the successful execution and delivery of a residential building in accordance with its approved design, specifications, financial provisions and agreed construction period. It requires the coordination of materials, labour, equipment, finance, contractors, consultants and clients throughout the various stages of construction. When material prices increase unexpectedly, the financial arrangements made at the beginning of a project may become insufficient to sustain construction activities. This can lead to delays in purchasing materials, interruptions in work, changes in project specifications, disagreements between contractors and clients and extensions of the original completion period. Aibinu and Odeyinka (2006) explain that construction delays in Nigeria arise from several factors associated with project participants and external conditions, with significant consequences for project delivery. Similarly, Assaf and Al-Hejji (2006), in their study of large construction projects, identify financial, contractual and project-related factors among the causes of construction delays. These studies show that project completion is influenced by the ability of stakeholders to manage financial and operational risks throughout the construction process. Consequently, building material cost increases may intensify existing project management challenges and affect the timely delivery of residential buildings.

Despite the importance of housing development to social welfare and economic growth, the rising cost of building materials remains a challenge to the timely and successful completion of residential construction projects. Contractors and property developers may experience difficulties maintaining project budgets when material prices increase after construction has commenced. Smaller construction firms and individual developers may be particularly affected because they may have limited financial reserves or difficulty obtaining additional funds. Furthermore, inadequate cost forecasting, weak procurement planning and insufficient contingency allowances can increase the consequences of material price changes. The Project Management Institute (PMI, 2021) emphasises the importance of cost planning, risk management, monitoring and stakeholder coordination in achieving project objectives. Aibinu and Jagboro (2002) also recommend appropriate contingency provisions and improved project management procedures to reduce the adverse effects of construction delays. These considerations demonstrate the need for construction stakeholders to adopt effective approaches to anticipating and managing material cost variations. It is against this background that this study examines the effect of building material costs on housing project completion in Nigeria, using selected construction projects in Lagos State as a case study.

1.2 Statement of the Problem

The cost of building materials is one of the major financial considerations in housing construction because materials such as cement, reinforcement bars, sand, granite, blocks, roofing sheets, timber and finishing products are required at different stages of project implementation. In Nigeria, fluctuations in the prices of these materials can make it difficult for contractors and developers to maintain the budgets prepared before construction begins. When material prices increase during project execution, the original contract sum may become inadequate to cover the remaining construction activities. This situation can result in additional financial demands, delays in procurement, interruptions in construction work and difficulties in meeting agreed completion dates. Aibinu and Jagboro (2002) identify construction delays as a significant problem in Nigeria and establish that delays frequently result in cost and time overruns. Similarly, Akanni et al. (2014) specifically identify rising building material costs as a challenge affecting construction industry performance in Lagos State. The central problem, therefore, is that increasing or unstable building material costs may undermine the financial capacity of project stakeholders and make the completion of housing projects within approved budgets and schedules increasingly difficult.

Another problem concerns the difficulty contractors and developers face in preparing accurate construction estimates in an environment where material prices can change during project implementation. Construction estimates are usually prepared using prevailing market prices, estimated material quantities and anticipated project duration. However, where prices increase unexpectedly, contractors may have to revise their budgets, negotiate additional payments or seek alternative sources of finance. In situations where clients cannot provide additional funds, construction activities may slow down or stop completely. This challenge can be particularly serious for smaller construction firms and individual property developers with limited financial reserves. Babalola et al. (2022) found that inflation contributes to cost overruns in public sector building projects in Lagos State, demonstrating the financial consequences of unstable economic conditions for construction activities. Aibinu and Odeyinka (2006) also identify external and project-related factors as important contributors to construction delays in Nigeria. The problem is therefore not limited to the increase in material prices alone but also concerns the ability of contractors and developers to anticipate, manage and respond to cost variations throughout the construction process.

In Lagos State, the challenge is particularly important because of the continuous demand for residential accommodation and the high level of construction activities across the state. Developers undertaking residential projects may encounter rising costs associated with cement, steel, roofing materials, electrical fittings, plumbing materials and other construction inputs. Where these increases are not adequately anticipated, they may affect procurement schedules, construction quality, project scope and the ability to complete buildings within the expected period. In some cases, developers may reduce the quality or quantity of specified materials, postpone certain stages of construction or suspend projects while searching for additional funds. Kadiri et al. (2019) found that increases in material prices were among the major causes of delays in both public and private building projects in Lagos State. Akanni et al. (2014) similarly examined the implications of rising material costs for contractors, builders’ merchants and construction consultants in Lagos. However, there is a need to examine how these cost challenges affect the completion of selected housing construction projects, particularly in relation to project budgets, construction schedules and the measures adopted by stakeholders to manage material price variations.

Furthermore, although construction cost management and project delivery have received attention in previous studies, there remains a need for project-based evidence on the relationship between building material costs and housing project completion in Lagos State. The effect of material price increases may differ according to project size, procurement arrangements, contract type, construction duration, availability of finance and the financial capacity of contractors and clients. Without examining these factors, it may be difficult to establish the extent to which material costs contribute to project delays, budget overruns, changes in construction specifications and incomplete housing projects. Aibinu and Jagboro (2002) emphasise the importance of contingency allowances and improved project management in reducing the adverse effects of construction delays. Babalola et al. (2022) also demonstrate the influence of inflation on construction cost overruns in Lagos State. Accordingly, this study seeks to investigate the effect of building material costs on housing project completion in Nigeria, with particular attention to selected construction projects in Lagos State.

1.3 Aim and Objectives of the Study

The aim of this study is to examine the effect of building material costs on housing project completion in Nigeria, using selected construction projects in Lagos State as a case study.

The specific objectives are to:

Examine the major factors responsible for changes in building material costs in selected housing construction projects in Lagos State.
Assess the effect of building material cost increases on the construction budgets of selected housing projects in Lagos State.
Investigate the influence of building material costs on the timely completion of selected housing projects in Lagos State.
Examine the strategies adopted by contractors and developers to manage building material cost variations and improve housing project completion in Lagos State.

1.4 Research Questions

The following research questions will guide the study:

What are the major factors responsible for changes in building material costs in selected housing construction projects in Lagos State?
What is the effect of building material cost increases on the construction budgets of selected housing projects in Lagos State?
How do building material costs influence the timely completion of selected housing projects in Lagos State?
What strategies are adopted by contractors and developers to manage building material cost variations and improve housing project completion in Lagos State?