How do you determine the cost of your proposed building?


First-time house owners are often worried about how much they need to have in their bank accounts before they could complete a proposed building. In several discussions I have had with clients, one of the recurring questions is: “How much do you think I need to complete this building?” They often want instant and accurate answers which may not be readily available or easy to give due to many factors that are involved.

There are steps you can take to have an idea of what your new building would cost; even though, it is may not be precise, the differences would always be  minimal. Even if you have to spend a little above your estimate as a result of inflation and other contingencies, at least, you are being guided from the onset. King Solomon, in his thoughtful thinking queried: “What man will want to build a house but will not first sit down to calculate the cost if he has enough to complete it?” It is good to imbibe this admonition in order to avoid prolonged or abandoned project.

First, you have to know the cost of the land, in case, you have not bought one. This is important because the cost of land varies depending on location. A plot of land in Lekki Phase 1, for instance, is in the range of 45 million and 60 million; this amount alone is enough to build an exquisite 4-bedroom bungalow in Mowe or Ikorodu. So, if what you have in mind is about N50 million, you have to get a plot of land at an affordable price, say N5 million.

You also have to know the cost of procuring various documents necessary for your proposed building. The cost of Deed of Assignment, Survey Plan, Approved Building Plan, Regularisation (if required), and Certificate of Occupancy will add-up to the cumulative sum required for your project. Although, the state government has recently reviewed various charges on land transactions downwards, nonetheless, you have to know what to spend on them and factor them into your budget.

Next, give the picture of your dream home to an architect and let him come up with a suitable design. He will ask for details like the type of house you want; the number of floor, bedroom, living-room, kitchen, dining and veranda. You can add what you want the size of the rooms to be or perhaps, the part of the land you want the master’s bedroom to be located. Leave the rest to him and wait for your drawings.  His professional charges depend on the information you have provided and your negotiation ability. Whatever both of you agree on will also form part of your expenditure on the new building.

To get comprehensive cost details of your proposed building, take the drawings prepared by your architect to a Quantity Surveyor (QS) to prepare a Bill of Quantities (BOQ) for you. You are sure of getting accurate cost of the minutest aspect of the project. As I am writing this piece, I have a BOQ before me and it includes small elements like the number and unit costs of doors, frames, locks and hinges needed for the project. The total amount for the project is indicated towards the end of the last page. This is the best and the easiest way to know the cost of your project. Remember that you also have to pay the QS; unless he is your son-in-law ‼‼‼

You can calculate the cost of the building yourself. Although, this could be a cumbersome and tedious exercise, especially for those who are not at home with figures, but it is not impossible.  You can start by identifying the number of items like doors, frames and windows in the house before you go to complex ones like blocks, cement, sand, planks, granite, iron rods, ceiling boards and roof materials. You can then go to the market to get their current prices. Add about 25% of the total cost of the materials to make for what you will pay as labour charges to workers and transportation of materials to site.

Even if you are going to engage the services of a building contractor, who would have to bring his own quotation, it is advisable to have your findings handy, at least for comparison purposes. Although, there could be variances in costs, but the margin must not be too wide. Where you are not satisfied, ask the contractor to explain how he arrives at his figures and let him convince you that he has calculated accurately. I have a client, who would always take his calculator to cross-check any figure given to him. Anytime I am able to convince him, he would stylishly ask for certain percentage as discount. He is fond of saying: “Elo lo fe din mi ninu e bayi?” (How much can you reduce from this amount?)

Another way to have an idea of the cost of you proposed building is to ask experienced artisans to submit individual estimates. Show the drawings prepared by your architect to the bricklayer, carpenter, iron bender, electrician, plumber, painter and others you intend to use for the construction. Their presentation will not only include the quantity and cost of materials, but also their labour cost. Go ahead to negotiate with them and get a better bargain before you put the figures together as the likely cost of your building.

On a final note, cost of construction is time-bound. This means that whatever amount you have is tenable only for a specified time, due to fluctuation in the market price of building materials. An estimate you made in January would have shot-upwards by August of the same year. So, allow a life-span for your estimate, say a maximum of 90 days.