Project – Assessment of Sustainable Design Strategies for Affordable Housing: A Case Study of Selected Low-Income Housing Estates in Lagos State.

CHAPTER ONE

INTRODUCTION

1.1 Background to the Study

Housing is one of the basic necessities of human life because it provides shelter, privacy, security, and an environment in which individuals and families can maintain their health and wellbeing. Beyond providing a roof over people’s heads, adequate housing should offer structural safety, access to essential services, reasonable comfort, and a suitable living environment. However, the provision of housing that is both affordable and adequate remains a significant challenge in rapidly urbanising cities, particularly for households with limited incomes. In Nigeria, the difficulty is intensified by rising land prices, increasing construction costs, limited access to housing finance, and the uneven distribution of formal housing opportunities. Ajayi, Faremi, Roger, and Uwaje (2020), in their study of affordable housing for low-income groups in Lagos, identified factors that constrain the provision and accessibility of housing for financially disadvantaged residents. These challenges demonstrate that affordable housing should not be assessed only by the number of housing units constructed, but also by whether the intended beneficiaries can obtain, occupy, and maintain the houses without excessive financial hardship.

Sustainable housing design has emerged as an important approach to addressing the relationship between housing affordability, environmental responsibility, building performance, and residents’ quality of life. Sustainable design involves planning and constructing buildings in ways that use resources efficiently, minimise adverse environmental effects, provide healthy indoor conditions, and remain functional throughout their useful life. In residential development, this may include efficient building layouts, appropriate orientation, natural lighting, cross-ventilation, durable materials, water conservation, energy efficiency, waste reduction, and accessible infrastructure. The United Nations Environment Programme (2023) identifies the built environment as a critical area for climate action because buildings influence energy consumption, resource use, and greenhouse gas emissions throughout their life cycles. Similarly, the World Green Building Council (2019) emphasises that building design can contribute to improved environmental performance and healthier indoor environments. These perspectives suggest that sustainable design is not merely about introducing expensive technologies; it also involves practical design decisions that improve housing performance while controlling construction and operating costs.

Affordable housing refers to housing that households can obtain and maintain without sacrificing other essential needs, including food, healthcare, education, transportation, and clothing. For low-income households, affordability is influenced by the initial purchase price or rent, access to finance, transportation expenses, utility bills, maintenance costs, and the durability of building components. A housing unit that appears inexpensive at the point of construction may become costly if it requires frequent repairs, consumes excessive energy, or is located far from employment and essential services. Conversely, a well-designed dwelling may reduce long-term expenses through passive cooling, natural lighting, water-efficient fixtures, durable materials, and reduced dependence on mechanical systems. Ajayi et al. (2020) showed that the provision of affordable housing for low-income residents in Lagos is affected by several economic and delivery-related constraints. Usman and Bawa (2025) likewise examined the relationship between sustainable design and affordability in Nigerian mass housing development, highlighting the need to integrate environmental and economic considerations into housing delivery. Therefore, sustainable design strategies should be evaluated in terms of both their environmental benefits and their practical affordability to intended residents.

One important sustainable design strategy is climate-responsive architecture, which adapts building form, orientation, materials, openings, shading, and ventilation to local climatic conditions. In warm and humid environments, poor building orientation, inadequate shading, limited cross-ventilation, and inappropriate roof or wall materials can increase indoor temperatures and create uncomfortable living conditions. Residents may then depend on fans, air conditioners, and other mechanical equipment, increasing electricity consumption and household expenses. Natural ventilation, appropriately positioned windows, shaded openings, roof insulation, reflective roofing materials, and well-designed building envelopes can help reduce heat gain and improve indoor comfort. A study by International Journal of Building Pathology and Adaptation researchers on low-cost retrofit packages for residential buildings in hot-humid Lagos found that passive design interventions could improve thermal comfort and reduce annual energy consumption under the modelled conditions (2019). Although that study focused on retrofitting existing buildings, its findings are relevant to the design of new affordable housing because many climate-responsive measures can be incorporated at the planning stage. This makes climate-responsive design an important area for assessing the sustainability of low-income housing estates in Lagos State.

The selection of building materials and construction methods is another important dimension of sustainable affordable housing. Conventional construction may become expensive when materials require substantial transportation, specialised installation, high energy inputs, or frequent replacement. Sustainable alternatives may include locally available materials, appropriately engineered earth-based products, recycled materials where safe and suitable, efficient block systems, and construction methods that reduce waste. However, the use of local or alternative materials must not compromise structural integrity, durability, fire safety, moisture resistance, or compliance with relevant building standards. Atamewan and Olagunju (2017), in their study of sustainable low-income housing and practicable minimum design standards in Bayelsa State, argued that housing standards need to reflect the socioeconomic realities of low-income urban residents. Their work also highlighted the importance of realistic minimum standards and housing approaches that allow improvement over time. Usman and Bawa (2025) similarly discussed the need to integrate sustainability with affordability in Nigerian mass housing. These studies indicate that material selection and construction methods should be evaluated according to initial cost, availability, durability, maintenance requirements, environmental impact, and suitability for the local context.

Sustainable housing design also involves the quality of the residential environment beyond the individual building. Housing estates require functional drainage, reliable water supply, sanitation, waste management, safe access routes, public spaces, and reasonable connections to transport, schools, health facilities, and employment opportunities. Where these services are absent or poorly maintained, residents may face additional expenses, health risks, flooding, long journeys, and reduced quality of life, even if the buildings themselves are affordable. Akinwande and Hui (2024), in their analysis of informal housing strategies in Lagos, examined the wider challenges of providing suitable affordable housing for urban poor households and the importance of understanding how housing is produced and accessed in practice. Afolayan and Ajibowu (2024), examining sustainable public low-income housing delivery through the case of Surulere Rehousing Estate in Lagos, also addressed the relationship between public housing provision and the long-term outcomes experienced by low-income residents. In addition, research on housing and neighbourhood quality in Lagos by Ibem (2012) identified deficiencies in building conditions and neighbourhood infrastructure in several public housing estates. These findings show that the sustainability of low-income housing should be assessed through both building design and the supporting physical and social infrastructure of the estate.

Lagos State provides a relevant setting for assessing sustainable design strategies because urban growth, high land values, pressure on infrastructure, and demand for affordable accommodation create complex housing challenges. Low-income households may depend on public housing estates, private low-cost developments, rental accommodation, and informal housing arrangements, each with different levels of building quality and access to services. The effectiveness of sustainable design strategies in this context depends on whether they can be incorporated without making housing financially inaccessible to the people they are intended to serve. Ogundipe, Owolabi, Ogunbayo, and Aigbavboa (2024) investigated factors inhibiting affordable housing provision in metropolitan Lagos and identified constraints relating to land and tenure security, socioeconomic conditions, construction materials and technologies, supply chains, community collaboration, and urbanisation. These findings demonstrate that sustainable housing outcomes are shaped not only by architectural decisions but also by financial, institutional, and implementation conditions. An assessment of selected low-income housing estates can therefore provide useful evidence on the sustainable strategies already adopted, their perceived effectiveness, their affordability implications, and the barriers limiting their wider application. Such evidence is important for developing housing solutions that balance cost, environmental performance, durability, comfort, and residents’ needs.

1.2 Statement of the Problem

The provision of affordable and adequate housing remains a major challenge for low-income households in Lagos State. Rising land prices, high building-material costs, limited access to housing finance, and increasing construction expenses make it difficult for many households to obtain suitable accommodation. Although public and private housing initiatives have sought to address this problem, the availability of housing units does not necessarily mean that such units are affordable, environmentally sustainable, or suitable for long-term occupation. Ajayi et al. (2020) identified several constraints affecting affordable housing provision and accessibility for low-income groups in Lagos. Similarly, Ogundipe et al. (2024) identified land-related, socioeconomic, technological, and institutional barriers to affordable housing provision in metropolitan Lagos. The problem, therefore, extends beyond the shortage of housing units to include the need for housing designs that meet the financial and practical needs of low-income residents while maintaining acceptable standards of safety, comfort, and environmental performance.

Another problem concerns the limited integration of sustainable design strategies into housing solutions that must remain affordable to low-income households. Strategies such as natural ventilation, daylighting, solar shading, energy-efficient building envelopes, water conservation, and appropriate material selection can improve building performance. However, their adoption may be constrained by inadequate technical knowledge, limited initial investment, construction practices, and concerns that sustainable features will increase the cost of housing. Usman and Bawa (2025) examined the relationship between sustainability and affordability in Nigerian mass housing and highlighted the need to reconcile environmental objectives with the economic realities of housing delivery. Atamewan and Olagunju (2017) also emphasised the need for practical housing standards that reflect the circumstances of low-income residents. Without careful evaluation, developers may either omit beneficial sustainable features to reduce initial costs or introduce expensive technologies that make completed housing units inaccessible to the intended beneficiaries.

A further problem relates to the actual performance and long-term liveability of low-income housing estates. Housing may be described as affordable at the point of purchase or allocation but may impose substantial costs on residents through poor ventilation, excessive indoor heat, high electricity consumption, inadequate drainage, water shortages, defective building components, and frequent maintenance requirements. Research on housing and neighbourhood quality in Lagos by Ibem (2012) identified deficiencies in building conditions and neighbourhood infrastructure within selected public housing estates. In addition, the study of low-cost retrofit packages for residential buildings in hot-humid Lagos, published in the International Journal of Building Pathology and Adaptation in 2019, demonstrated the potential benefits of passive design interventions for thermal comfort and energy consumption. These findings indicate that the long-term performance of housing depends on the interaction between building design, material quality, infrastructure, and maintenance. However, the extent to which sustainable design strategies are implemented and perform effectively in selected low-income housing estates requires further assessment.

Finally, although existing studies have examined affordable housing constraints, minimum design standards, housing quality, and sustainability in Nigeria, there remains a need to assess these issues together within selected low-income housing estates in Lagos State. Ajayi et al. (2020) focused on barriers to affordable housing for low-income groups, while Ogundipe et al. (2024) investigated factors inhibiting affordable housing provision in metropolitan Lagos. Atamewan and Olagunju (2017) examined practicable minimum design standards, and Usman and Bawa (2025) considered the relationship between sustainable design and affordability in mass housing development. These studies provide important foundations, but an estate-level assessment can further investigate the sustainable design strategies actually adopted, their perceived contribution to affordability and environmental performance, and the barriers to their implementation and maintenance. Without such evidence, it may be difficult for housing developers, policymakers, and estate managers to determine which strategies are both practical and beneficial for low-income residents. This study therefore assesses sustainable design strategies for affordable housing in selected low-income housing estates in Lagos State.

1.3 Aim and Objectives of the Study

The aim of this study is to assess sustainable design strategies for affordable housing in selected low-income housing estates in Lagos State.

The specific objectives are to:

1. Identify the sustainable design strategies adopted in selected low-income housing estates in Lagos State.

2. Examine the contribution of sustainable design strategies to housing affordability, energy efficiency, and residents’ comfort.

3. Assess the challenges affecting the implementation of sustainable design strategies in selected low-income housing estates.

4. Determine measures for improving the adoption of sustainable design strategies in affordable housing development in Lagos State.

1.4 Research Questions

The following research questions will guide the study:

1. What sustainable design strategies have been adopted in selected low-income housing estates in Lagos State?

2. How do sustainable design strategies contribute to housing affordability, energy efficiency, and residents’ comfort?

3. What challenges affect the implementation of sustainable design strategies in selected low-income housing estates?

4. What measures can improve the adoption of sustainable design strategies in affordable housing development in Lagos State?

1.5 Research Hypothesis

The following null hypothesis will be tested at the 0.05 level of significance:

H₀: There is no statistically significant relationship between the adoption of sustainable design strategies and perceived housing affordability in selected low-income housing estates in Lagos State.

1.6 Significance of the Study

The findings of this study are expected to be useful to housing developers, architects, urban planners, government agencies, estate managers, low-income residents, and future researchers.

Housing developers: The study may help developers understand which sustainable design strategies can improve building performance without unnecessarily increasing construction costs. It may encourage the incorporation of passive design, efficient material use, durable components, and practical water and energy conservation measures into affordable housing projects.

Architects and building professionals: The study may provide information on the practical application of sustainable design principles in low-income housing. Architects, quantity surveyors, builders, and other professionals may benefit from a clearer understanding of the relationship between design choices, construction costs, building performance, and residents’ needs.

Government and policymakers: The findings may support the development and review of housing policies, minimum design standards, and affordable housing programmes. They may also assist policymakers in identifying financial, technical, and institutional barriers that need to be addressed to encourage sustainable housing delivery.

Low-income residents: The study may raise awareness of the long-term benefits of sustainable housing features, including improved ventilation, better indoor comfort, reduced energy consumption, and lower maintenance expenses. It may also help residents identify practical improvements that can make their homes more comfortable and economical to maintain.

Estate managers: The findings may assist estate managers in identifying design and maintenance issues that affect the durability, environmental performance, and liveability of residential estates. This may encourage better maintenance planning and more efficient management of shared infrastructure.

Researchers and students: The study may contribute to academic literature on sustainable architecture, affordable housing, environmental design, and urban development in Nigeria. It may also provide a basis for further research comparing different housing estates, design approaches, and resident experiences.

1.7 Scope of the Study

The study focuses on the assessment of sustainable design strategies for affordable housing in selected low-income housing estates in Lagos State, Nigeria. Its geographical scope is limited to the housing estates selected by the researcher within the state.

The content scope covers the identification of sustainable design strategies, their contribution to housing affordability and building performance, the challenges affecting their implementation, and measures for improving their adoption. The design strategies considered may include natural ventilation, daylighting, solar shading, energy-efficient building features, appropriate material selection, water conservation, waste management, durable construction, and the provision of functional neighbourhood infrastructure.

The study will also consider residents’ experiences and perceptions of the affordability, comfort, maintenance requirements, and general suitability of their housing. It will not assume that all sustainable strategies are present in every estate; rather, their adoption and effectiveness will be examined based on the evidence collected.

1.8 Limitations of the Study

The study may encounter limitations relating to access to selected housing estates, availability of building design documents, and willingness of residents or estate managers to provide information. Some respondents may not possess technical knowledge of the sustainable design features incorporated into their homes. Their responses may therefore reflect personal experiences rather than professional assessments.

Differences in the age, design, construction quality, occupancy, and maintenance of the selected housing estates may also affect comparisons. In addition, the researcher may have limited time and financial resources for conducting detailed energy audits, material testing, or long-term environmental monitoring.

To address these limitations, the study will use appropriate data collection instruments, explain questions clearly to respondents, and examine available physical evidence where access permits. The findings will be interpreted in relation to the selected estates and the methods used, rather than automatically generalised to every low-income housing estate in Lagos State.

1.9 Operational Definition of Terms

Sustainable design strategies: Planning and building approaches intended to reduce environmental impact, improve resource efficiency, enhance indoor comfort, and support the long-term performance of housing.

Affordable housing: Housing that households can obtain and maintain without undue sacrifice of other essential household needs.

Low-income housing estate: A planned residential development intended primarily to provide accommodation for households within lower-income groups.

Sustainable housing: Housing designed, constructed, operated, and maintained to balance economic affordability, environmental responsibility, durability, and residents’ wellbeing.

Passive design: Design approaches that use building orientation, natural ventilation, daylighting, shading, and building materials to improve comfort and reduce dependence on mechanical systems.

Energy efficiency: The ability to provide a required level of comfort or building service while using less energy.

Housing affordability: The extent to which the cost of obtaining and maintaining a dwelling is manageable in relation to a household’s income and other essential expenses.

Project – Assessment of Sustainable Design Strategies for Affordable Housing: A Case Study of Selected Low-Income Housing Estates in Lagos State.