Abstract:
The cost of building materials poses a significant threat to both the construction industry and home owners. Building materials have been established to account for between 35 to 70% of the total construction input depending on type of projects. They constitute the largest single input in building construction, of which educational and residential houses are part. The cost of building materials contribute significantly to the success of building delivery. The study aimed at assessing the individual cost effect of the selected building materials which are cement, sand, granite, concrete, block, block-wall and plaster on the total cost of building projects in Edo State. Archival design method was adopted through document studies. Twenty-Three (23) Bill of Quantities for already executed building projects were collected from both consultant and contracting Quantity Surveying firms in Edo State. Twelve (12) out of the collected executed building projects were used to assess the cost effects of selected building materials on total cost of educational building projects while eleven (11) Bill of Quantities were used to assess the cost effects of selected building materials on total cost of residential building projects. The study revealed and established the individual cost effect of the selected building materials in educational building to be; concrete (17.92%), cement (12.58%), block-wall (8.92%), block (4.92%), granite (4.08%), plaster (3.08%) and sand (2.25%) while in residential building projects, concrete (13.91%), cement (11.36%), block-wall (11.27%), block (7.18%), granite (4.27%), plaster (3.36% and Sand 2.91%. The study further revealed and established cost effects of cement, sand and granite to the total cost of concrete to be cement (39%), sand (3%) and granite (22%). Cement (33%) and sand (12%) of the total cost of block-wall. and 34% and 5% of the cost of plaster is always used to purchase cement and sand respectively in educational building, while in residential building projects, the established cost effects are cement (38%), sand (5%) and granite (15%) of the total cost of concrete, cement (35%) and (14% ) of the total cost of block-wall is expended on cement and sand respectively and lastly, 27% and 6% of the total cost of plaster is used to purchase cement and sand respectively. The research finally revealed that increase in cost of cement and concrete would significantly affects total cost of both educational and residential building projects in Edo State.