1.1 Introduction
Local materials are those materials that can be readily available in quantity at a particular location or area at a certain time. These materials could be abundant in quantities depending on the geographical location of the area. These materials have some advantages over most imported materials and since they are readily available, makes them cheaper and quite available thus reducing the cost of construction.

1.2 Background to the study
The issue of the cost of construction work is one that is barely far from the minds of the construction clients, design teams, contractors and the quantity surveyors.
Previous studies in the building sector have indicated that building materials account for between 50 to 60% of the total construction input (Adedeji, 2012; Ogunsemi, 2010:2)
Nega (2008), opined that increase in cost of construction is caused by increase in the cost of building materials, an increase which has a significant impact on overall budgeted cost of construction. Construction cost has been the most significant consideration for the execution of any construction project. We can observe that the cost of building materials is dependent on the quality, quantity, time, place, buyer and seller. The ability to attract labour and to source materials in the locality is a key factor in ensuring that irrelevant and unnecessary travelling, importation and transport cost are not incurred in carrying out of construction work.
The more frequent use and patronizing of local producers and manufacturers, which leads to the reduction of importations can also promote the exportation of these local materials, hence, improving the economic development of the nation. The use of these local materials does not only involve in the structural frame work of construction of buildings but also involves in the interior décor and furnishing of these building spaces.
All these will result in more employment, good construction, affordable housing and better economy.

1.3 Problem statement
Cost is undoubtedly the most important concern in any business endeavor, not least in the building construction industry. Poor cost performance in construction projects has become a major concern for both contractors and clients (Xiao & Proverbs, 2002)
The increase in the price of building materials has multiple effects on housing development (Jagboro & Owoeye, 2004).
The cost of construction in Nigeria does not seem to be cheap as housing is not easily affordable and this can be traced down to the cost of these building materials. This has become a problem for construction in Nigeria because of the over reliance on imported construction materials and an abandonment of our local materials. It is high time to look into our local readily available materials which will help in the reduction of general cost in construction.

1.4 Research questions
What are the factors responsible for the increase in cost of building materials?
What are the effects of the use of local materials?
What are the criteria for the selection of local materials in construction of buildings?

1.5 Aims and objectives of the study
The aim of the study is to reduce the general cost of construction in Nigeria.
To examine the factors responsible for the increase in the cost of building materials
To examine the use of local materials in the construction of buildings
To examine the criteria for the selection of local materials in the construction of buildings

1.6 Significance of the study
This research study will enable Clients and Building Professionals to indulge in an economic approach as to construction of buildings. This will also make housing cheap and affordable for users and will reduce homelessness and improve economy.
This research will also help to improve Client confidence in Building professionals and Consultants, reduce investment risk and boost housing affordability.

1.7 Scope and limitation of the study
This study is to be carried out in Benin city, Edo state. Information will be gathered from construction stakeholders and materials suppliers in Egor and Ovia North East Local Government Area.