Journal of Environmental Design and Management

Adaptability and sustainability of public housing in Lagos, Nigeria

2018-04-26T10:44:16+00:00

This paper examined the concept of adaptability with reference to public housing. The report of a survey research of eight purposively selected public housing schemes in Lagos, Nigeria, provided complimentary empirical basis. Primary data were obtained through questionnaire administration on a sample of 806 household heads, from which 760 questionnaires (94.3%) were returned. The survey revealed that the majority of respondents across house-types rated their housing low in terms of three measures of adaptability: socio-spatial adaptability (73%); socio-economic adaptability (80.1%); and possibility of altering house design (64.3%). The paper discussed issues related to adopting adaptable building systems and concluded on the need for greater consideration of adaptability in public housing provision. This would however require innovative housing delivery systems for the creation of environments that embrace diversity, enhance adaptability, and contribute to sustainability.

Adaptability and sustainability of public housing in Lagos, Nigeria

2018-04-26T10:44:35+00:00

Place attachment in selected urban and semi - urban students' residences in southwestern Nigeria

2018-04-26T10:44:16+00:00

The focus of this study was place attachment in students' residences. The aim was to examine the levels, dimensions and predictors of place attachment in urban and semi-urban halls of residence. A stratified sample of 203 respondents completed a questionnaire and the results confirmed that students were attached to their residences and became so in a very short time. A multi-dimensional conception of place attachment was also supported because a factor analysis yielded five dimensions of place attachment. Place attachment was found to vary with different levels of the residence (t=4.187, df=201, p<0.000) and between the urban and semi-urban halls (U =3886.5, Z= -2.625, p<0.009). The predictors of place attachment were level of study, age, intensity of use and the type of hall (whether urban or semi-urban). Place attachment was not influenced by the decoration behavior, but rather, it was a predictor of decoration behavior. In conclusion, a contextual and multi-dimensional view of place attachment was supported and the implications for planning and further research were highlighted.

Place attachment in selected urban and semi - urban students' residences in southwestern Nigeria

2018-04-26T10:44:35+00:00

An investigation into the pozzolanic properties of volcanic ash sample obtained from Dutsin Dushowa in Jos Plateau

2018-04-26T10:44:16+00:00

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This study investigates the pozzolanic properties of the volcanic ash (VA) obtained from Dutsin Dushowa in Kerang,Plateau State. Chemical analysis of the VA obtained in the study area was carried out to determine the oxide contents.Tests on some physical properties (specific gravity, fineness, soundness, consistency, water requirement and setting times -initial and final) of the VA and VA-blended cement samples were also carried out.The resultshows a Silicon dioxide (SiO2)content of 41.13% and a total Silicon dioxide, Iron oxide, and Aluminium oxide (SiO +Fe O +Al O ) content of 70.99%. The VA sample has a specific gravity of 2.65 kg/m3and the VA-blended cement was noted to be finer than the control cement. The soundness of the VA-blended cement ranged between 1.5 and 4.5 for replacement levels of 0% to 30%. The consistency increased from 30.0% to 31.5% as VA substitution increase from 0% to 30%. The water required for a standard consistency was noted to increase as the VA content increased. The initial and final setting times increased from 50 to 105 minutes and 135 to 180 minutes respectively for this replacement levels. All the VA-blended cements thereby satisfy the various code requirements up to the 30% replacement levels, hence suitable for use in concrete.

An investigation into the pozzolanic properties of volcanic ash sample obtained from Dutsin Dushowa in Jos Plateau

2018-04-26T10:44:35+00:00

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Influence of fly ash and silica fume on the compressive strength development of Portland cement concrete

2018-04-26T10:44:16+00:00

To make concrete more environmentally compatible, this paper investigated the compressive strength development of binary and ternary cement combination concretes containing ordinary Portland cement, fly ash and silica fume at various ages, water/cement ratios and strengths. Due to its higher fineness and improved pozzolanic reactivity, silica fume as binary and ternary cement components resulted in concretes with improved compressive strengths at both early and later ages. While fly ash, at equal water/cement ratios, would reduce compressive strength at early ages, its compressive strength increased progressively with age to contribute to later-age strength development. However, to effectively support long-term strength development, at equal water/cement ratio, a total cement addition content of more than 20% would be required. While the cement combination concretes were generally more environmentally compatible than ordinary Portland cement concrete because of their lower embodied carbon-dioxide contents, 29 (64%) of the 45 cement combination concrete options investigated at equal strengths between 42.5 and 62.5 N/mm2 were cheaper than ordinary Portland cement concrete. At equal strength, fly ash contributed substantially to strength development. Hence, concrete options, majorly fly ash binary cement concretes and some ternary cement concretes at a total replacement level of not more than 35%, are cheaper than ordinary Portland cement concrete.

Influence of fly ash and silica fume on the compressive strength development of Portland cement concrete

2018-04-26T10:44:36+00:00

Strength development and crack pattern of coconut fibre reinforced concrete (CFRC)

2018-04-26T10:44:16+00:00

In tropical regions, natural fibres are abundantly available which when utilized as reinforcement will reduce thecost ofreinforced concrete.Hence, this paper investigated the use of coconut fibres as reinforcement in concrete. Coconut fibres were extracted from coconut pods and chopped into an average length of 40 mm. Concrete of mix ratio 1:2:4 was produced which contained coconut fibre of 1, 2, 3 and 4% by weight of cement. Compressive strength and modulus of rupture of CFRC specimens were determined following standard procedures at curing ages of 7, 21, 28 and 56 days. Crack pattern was also monitored. The results showed that the water-cement ratio for workable mix increased from 0.62 to 0.70 as coconut fibres (CF) increased from 0 to 4%, while the compressive strength only increased up to 2% CF inclusion but dropped afterwards when compared with normal concrete (NC). The 28-dayflexural strength of CFRC increased with increase in the coconut fibre in concrete. There was gradual tensile failure in CFRC with hair-like crack as compared to sudden failure with wide crack from tension zone to compression zone in normal concrete. The study concluded that up to 2% content of CFis recommended for concrete reinforcement in minor structural elements.

Strength development and crack pattern of coconut fibre reinforced concrete (CFRC)

2018-04-26T10:44:36+00:00

Value management awareness and utilization in construction projects in Lagos state, Nigeria

2018-04-26T10:44:16+00:00

The aim of this of study is to investigate the levels of awareness and utilization of value management (VM) in construction projects. The objectives of this study are to analyze the levels of awareness of value management of construction professionals and to examine the extent of utilization of VM in the delivery of construction projects in Lagos State, Nigeria. Structured questionnaire was used to collect information from construction professionals who undertook VM recently. Snowballing sampling technique was used in selecting seventy (70) respondents and only twenty-eight (28) responses were found fit for data analysis. Results show that VM concept is known to respondents but it is not frequently used for projects. Level of awareness of VM is still low. Level of utilization of VM for project delivery is low and some informal VM methods are used in practice. The study findings have an implication for policy such that a public law should be enacted for use of VM for all public construction projects. The study concludes that organizations have not fully embraced VM on construction projects and VM is used only on few projects. The study recommends that curricula of postgraduate courses in construction related fields are to include VM courses; while professional bodies are to spread awareness and enlighten their members on the use of VM for projects.

Value management awareness and utilization in construction projects in Lagos state, Nigeria

2018-04-26T10:44:36+00:00

A comparative analysis of direct and indirect real estate investment performance in Lagos, Nigeria

2018-04-26T10:44:16+00:00

The paper examined comparatively the performance of direct and indirect real estate investments within the period of 2000 and 2012, in Lagos Nigeria. The total return for each of the real estate investment vehicles were analyzed with the use of mean returns, standard deviation, coefficient of variation and sharp index. The results showed that indirect real estate investment performed better than direct real estate investment on a nominal basis with a mean annual return of 34.21% as against 30.29% and 25.69% for direct commercial and residential real estate investments respectively. However, direct real estate investments performed better in terms of risk-adjusted return with Coefficient of Variation of

0.16 and 0.24 for residential property and commercial property as against 3.02 for indirect real estate investment. The study concluded that while investors in real estate may benefit from both direct and indirect real estate investment media, they may stand to benefit more if they consider direct real estate investments.

Keywords: Investment vehicles, Nigeria, Performance analysis, Property company shares, Real estate investment.

A comparative analysis of direct and indirect real estate investment performance in Lagos, Nigeria

2018-04-26T10:44:36+00:00

Keywords: Investment vehicles, Nigeria, Performance analysis, Property company shares, Real estate investment.

A study of Ikorodu vernacular architecture and its decorative motifs

2018-04-26T10:44:16+00:00

Ikorodu, for its nearness to Lagos, increasing developments andgrowing population, is experiencing a lot of transformation which in recent times has led to selling of old houses for the construction of banks, eateries, and shopping complexes, and demolition due to reconstruction of old roads. In the face of this problem, this study was carried out on the existing Ikorodu vernacular architecture and its decorative motifs before some of them will be sold or demolished. Domestic Afro-Brazilian houses with unique decorative motifs across the town were selected randomly and classified into two: a) houses belonging to the rich and noble and b) houses belonging to the middle and low-classes.Decorative motifs found on the faÃ§ade of the houses were analysed against the culture and lifestyles of the people. Five categories of motifs were analysed and discussed, namely: Animal motifs, Plant motifs, Linear motifs, Geometric motifs, Metaphorical motifs and Colonial-influenced motifs.The study found that Ikorodu architecture is highly decorative with meaningful motifs that communicate the beliefs of the people, and some motifs are used on more than one house. The study concluded that Ikorodu vernacular architecture is a means of understanding the lifestyle and beliefs of the owners.It was recommended that effort should be geared towards the preservation of the houses by the government through legal means, so that the owners will not be tempted to sell them for huge money often offered by owners of private commercial enterprises.

A study of Ikorodu vernacular architecture and its decorative motifs

2018-04-26T10:44:36+00:00

Decision support weighted score system (DSWSS) for selection of construction contractor in Nigeria

2018-04-26T10:44:16+00:00

The aim of this study was to develop a computer aided methodology to determine the weights of the different parameters for contractor selection as there is no standard assessment procedure for evaluating contractor selection criteria (CSC) by decision makers in Nigeria. A survey research is adopted for this study via descriptive research design. The populations are public clients and consultant organisation. Stratified sampling technique method is used because they are of the same homogenous group, that is divided into strata. Questionnaires were distributed to clients' organization and construction professional in consulting firms. The lists of practicing construction professionals were obtained from their professional bodies. The sample size was calculated using Cochran formula while Statistical Package for Social Science (SPSS) 17th version was used to analyse the biographical information of the respondents. The computer aided methodology used is a desktop application known as C Sharp (C#). The result gives the weights in percentage that could be assigned to contractor selection criteria a (CSC) at both prequalification and tender evaluation criteria. In conclusion, the weighted percentage can be used by decision makers during selection of contractor for construction projects to ensure objectivity judgment.

Decision support weighted score system (DSWSS) for selection of construction contractor in Nigeria

2018-04-26T10:44:36+00:00

An assessment of current preliminary cost estimating practice in Nigeria

2018-04-26T10:44:16+00:00

The study assessed the preliminary cost estimating practice in Nigeria with a view to determining the methods in use, the level of accuracy of preliminary cost estimates and the factors influencing their accuracy. A structured questionnaire was used to elicit data from 60 randomly selected qualified Quantity Surveyors in the 156 consulting firms in Lagos State. The data collected were analysed using mean scores, percentages and Factor Analysis. The results indicated that the predominant methods of preparing preliminary cost estimates by consulting Quantity Surveyors were approximate quantities and superficial (floor area) methods. The study also showed that while low rise buildings were under estimated by 8.87%, high rise buildings were over estimated by 23.43%. On overall, building projects were overestimated by 14.36% of their actual costs with project team factors, tendering-related factors, contractor organizational factors, competence-related factors, and project information factors mostly responsible for inaccuracy of preliminary cost estimates.

An assessment of current preliminary cost estimating practice in Nigeria

2018-04-26T10:44:36+00:00

Redefining cost control framework for construction budgetary management

2018-04-26T10:44:17+00:00

Construction projects are regarded as successful if they are delivered at the right time, at an appropriate cost and to quality standard. Among these success factors, the issue of cost is very significant. The purpose of this paper is to propose a framework to redefining cost control procedure in construction budget management. This is with a view to addressing the incessant problem of cost overrun of construction projects. A review of the conventional cost control techniques and their appropriateness to the modern construction cost management process was carried out. Findings from the review of major projects around the world, using the conventional cost control methods revealed a significant cost overruns ranging up to 70% of the initial budget estimate. This signals the shortcomings of the existing cost control theories and procedures. A framework which provides an opportunity for taking pro-active measures, at various stages of construction processes, is therefore proposed. The framework could serve as a basis for keeping the cost of construction projects within the estimated budget and checking the hitherto construction budget escalation.

Redefining cost control framework for construction budgetary management

2018-04-26T10:44:36+00:00

Time and cost models for building projects using prequalification and contract award data in Nigeria

2018-04-26T10:44:17+00:00

The purpose of this study was to develop models for predicting the probable completion cost and time of building projectsusing contractors' prequalification assessment, the initial contract sum and the proposed contract duration.Data on Contractors' Prequalification Assessment (CPA), Initial Contract Sum (ICS), Planned Contract Duration (PCD), Project Completion Cost (PCC) and Actual Contract Duration (ACD) for 77 completed building projects were sourced from Bureau of Public Procurement (BPP). Multi-colinearity test was conducted on the variables in order to avoid multiple correlations among the data before subjecting them to Multiple Regression Analysis (MRA). The goodness of fit of the models derived as defined by the value of R2 was found to be 98.2% and 92.80% for cost and time; thus signifying thatabout 2% and 7% of the residual variations in the independent variables were not included in the cost and time models respectively. The result of the research would therefore be a bold step at selecting competent contractors who can deliver projects to time and within budgeted cost in Nigeria.

Time and cost models for building projects using prequalification and contract award data in Nigeria

2018-04-26T10:44:36+00:00

Accessibility as a determinant of social service centres utilization Boripe local government area in Osun State, Nigeria

2018-04-26T10:44:17+00:00

Accessibility to social services is regarded as a major indicator of both human and economic development. However, the developing nations of the world are grossly besieged by poor accessibility especially by road to social service centres (SSC) and lopsidedness in the spatial distribution where they are available. This has greatly hampered the ability to provide services that are responsive to the societal challenges facing this region, within a developmental context. Therefore, the study examined the accessibility to these SSC (basically education, health and recreational) by the patrons in terms of the condition of road, distance travelled and mode of transportation as a determinant to their utilization. A total 338 respondents were selected using systematic random sampling from the six (6) political wards as delineated by INEC in the study area for questionnaire administration. Data collected were analyzed using descriptive statistics, crosstabs and chi-square. A total of 122 SSC were identified in the study area, majority (45.6%) of the SSC are accessible by untarred road, 38.7% by tarred road while 15.7% by footpath. In addition, 50.0% of the patrons travelled by foot against 30.0% who accessed the SSC by taxi, while significant relationship was established between the SSC and mode of transportation with c2= 181.9, df =16 and p = 0.000. Condition of roads, which are basic means of access to the SSC, should be improved upon. Such will not only safe the patrons of the travel time but also the inherent cost which may be applicable to enhance their utilization and derivable benefits.Keywords: Accessibility, Location, Patronize, Social Services, Utilization.

Accessibility as a determinant of social service centres utilization Boripe local government area in Osun State, Nigeria

2018-04-26T10:44:36+00:00

An assessment of the environmental effects of sawmilling activities on residents of Ile-Ife, Nigeria

2018-04-26T10:44:17+00:00

Sawmill industry is one the common industrial establishments located close to or within residential areas in forest belt of Nigeria. Expectedly, it has caused environmental and socio-economic impacts on residents. Along this line, this study assessed the environmental effects of sawmilling activities on residents living at varying distances from sawmills in Ile-Ife, Osun State, Nigeria. Data for the study were collected from selected 325 households and 30 sawmill workers in the study area using systematic sampling method. Information obtained from both residents and sawmill workers focused on their socio-economic characteristics, materials used in sawmilling activities, mode and period of operation, types of waste, and method and treatment of waste disposal. Furthermore, noise level measurement was carried out at every 100m interval within the 900m radius of the two sawmill sites from 8am to 5pm for a period of one week using Kamplex audiometer (model 27). Findings from workers revealed that the most prevalent environmental problems in the sites were noise pollution, smoke and odour, representing 14.4%, 13.4% and 12.9% respectively. Furthermore, the most prevalent human health problems were migraine, hearing loss and catarrh which accounted for 13.5%, 13.5% and 12.6% in the two sites respectively. The study established that there was a significant difference between distance of residences from sawmills and severity of smoke. Noise level measurement was found to vary significantly across the two sawmill sites (F=102.329 and F=98.323=0.000) in the study area. The study also established that there was a significant difference between sawmill distance to residence and severity illness and migraine. The study concluded that significant variation existed in the physical, environmental and human health problems across the different residential zones in the study area.

An assessment of the environmental effects of sawmilling activities on residents of Ile-Ife, Nigeria

2018-04-26T10:44:36+00:00

Comparative study of state and federal governments' site and services schemes in housing delivery in Ilorin, Nigeria

2018-04-26T10:44:17+00:00

The study made a comparative study of state and federal government's site and services schemes in Ilorin, Nigeria. Both primary and secondary data were used for the study. Multi-stage and purposive sampling methods were adopted in administering questionnaire. Obanisunwa (federal) and Transit Camp (state) estates were purposively selected. All fully developed plots were purposively selected together with 40% of uncompleted/undeveloped plots in the estates. In all, 719 plots, comprising 340 (104 completed buildings and 240 uncompleted/undeveloped plots) in Transit Camp, and 379 (15 completed buildings and 364 uncompleted/undeveloped plots) in Obanisunwa schemes respectively, were sampled for questionnaire administration. Only 554 copies of the questionnaire administered were correctly filled, returned and used for analysis. Findings revealed that Obanisunwa estate was better rated than Transit Camp in terms of: plot allocation process (96.0% : 30.1%); allocation of plots to target groups (90.5% : 29.0%);and, land title document process (87.3% :29.6%); while Transit Camp estate was better rated than Obanisunwa in terms of: nature of management style (48.0% : 39.7%); satisfaction with level of maintenance of the estate (49.8% : 19.29%); level of development within the estate (51.7% : 19.2%); and level of plot development in terms of fully developed plots (32.8% : 6.3%). t-tests revealed that there was significant differences between the state and federal site and services schemes in the city ( = 0.177). It was concluded that although the two site and services schemes have failed to bring about significant increase in the housing stock in the city, the state's scheme fared better than the federal government's scheme. Strategies were proposed to enhance performance of site and services schemes in the city.

Comparative study of state and federal governments' site and services schemes in housing delivery in Ilorin, Nigeria

2018-04-26T10:44:37+00:00