Most of the previous studies on causes of valuation variance have concentrated on non-statutory valuation, with little attention to statutory valuation in both developed and developing countries, leaving a gap in the body of knowledge in this regard. Purposive sampling was adopted to select samples from registered estate surveyors and valuers in Kwara State, Nigeria. The data collection was done through a survey questionnaire given to 33 valuers and the Relative Importance Index (RII) was used to analyse the data collected. Findings showed that factors that fell within the range index of significant factors (0.841 to 0.979) are: experience in rating valuation, comprehensiveness of the law, unrealistic valuation assumption and availability of market indices for the input variables. Other significant factors are explicitness of the law, integrity of the valuer, valuer negligence, absence of quality control and training in rating valuation. The findings have practical implications on rating valuation stakeholders.

Contrary to the perception that estate surveyors and valuers are only concerned with the valuation of lands and buildings, their scope of work included art and artifact valuation. The valuation of art and artifacts can pose serious difficulties to a young valuer, as experienced valuers can establish expertise in the arts area. This study examines the possible challenges in the valuation of art and artifacts. Structured questionnaires were administered on 17 estate surveying and valuation firms in Abeokuta, Ogun State. The data was analyzed using the Relative Important Index. The results revealed that the valuation of art and artifacts requires more specialized knowledge and practical skills than what is required for valuing lands and buildings. The results further show that valuers are confronted with the challenges of a lack of information and inadequate access to past transaction records. This study recommends that, beyond the valuation of lands and buildings taught in schools, training on art and artifacts should also be incorporated in a curriculum and as well as professional training from time to time.

Purpose This study aims to review the approaches used in the analysis of rental income of residential property in Abuja, Nigeria, to strengthen the existing investment performance approaches initially relied upon by property investors towards having a better and reliable performance evaluation for property investment decision-making. Design/methodology/approach With the adoption of combined methodological approaches, quantitative data on rental history (2006–2016) were collected on the randomly selected residential investment properties (block of flats) available in the portfolio of estate surveying firms in the different locations/sub-markets of the study area. Data collected were analysed with the frequency mean and growth rate. Findings All the methodological approaches adopted for analysis displayed varying performance results. No particular sub-market maintains the same ranking position in any of the approaches. The developmental phases previously used as an indication of yield in the study area do not correspond with the status of rental income of sub-markets. Yield has been observed to be a mere attraction to property investment; it does not translate to income growth. Mean income (though a good indicator of changes in rental income) is not a reliable indicator of growth in income, and growth in the rate of income omitted the changes in rental income during the holding period. Research limitations/implications The study was restricted to historical rental income data on a block of flat-type residential property, and it does not include capital value analysis or inquire into the factors responsible for variation in rental income during the study period. The outcome of this study is only applicable to a block of 4 number three-bedroom flats residential property type. Practical implications Multiple simple methods of analysing rental income performance should be preferred to the single complex method. This will simplify investors’ rental income characteristics of investment towards a better understanding of rental property investment analysis. That rental value appreciates with time does not translate to an increase in the actual rental income of residential investment property. Social implications Through these performance approaches, ranking of the sampled properties in the study area sub-markets will enhance investors’ traditional diversification planning across the study area for an enhanced combination that can achieve latent profitability. The attention of investors is hereby called to these multiple approaches to enable them to merge their investment objectives with any or a combination of these approaches towards making rational investment decisions. Originality/value This seems to be the first advocacy for methodological paradigm shift applicable to direct residential property investment performance in Nigeria, using transaction rather than appraisal data.