Blog: How much will my building project cost? Five things to consider

Mark Kemp – Director

At the start of any building project, all clients want to know what it is likely to cost. Architects understand the building process from the very beginning of a project right through to the end. In order for your architect to be able to tell you how much your project is likely to cost, there are a number of considerations. Cost is driven by a well-established trinity of “Time—Cost—Quality”, but here are five other very important matters you should take into account.

The amount you want to spend is different from how much can you afford. Nobody wants to spend more than they need to, but everybody assesses value differently. The amount is called the Project Budget.

As well as considering how much the project will add to the value of the house, think also how much value it will add to you. This means carefully considering how you use the property and how long you intend to stay there.

The Project Budget is made up of a number of different elements such as:

You also have to consider what constraints or limitations there are to the project. These may be encountered early on at the planning stage, or later during the construction phase itself. 

Things that make the difference to the cost may not at first be obvious. These include whether or not there is enough space on the site for the builder to store the materials that will need to be delivered. Is that area a long way from the road? All these factors can affect the frequency of deliveries and how many times the materials need to be handled, which will increase the cost.

You may also impose additional constraints on the project. These include the time of year you want the work done and the value of the penalty charge if it is not completed within that time. Issues like this can have a big impact on the willingness of builders to price the works.

This is especially important in terms of wall and floor finishes, light fittings, number of switches and sockets and types of bathroom fittings or towel rails. Together these items can make up a sizeable proportion of the overall building cost. 

For instance, if you ask a builder how much it will cost to add an en-suite bathroom to a bedroom, the builder will want to give you a low price in order to get the work. Their cost might include all of the basics with some tiling in the shower and behind the basin. 

When you say you want it to include a self-flushing loo, floor to ceiling wall tiling all round, marble floor tiles, dimmable mood lighting, underfloor heating, a built-in drying room for towels and concealed cupboards behind flush, back-lit mirrors … the cost will go up!

Procurement is the term used to describe how you intend to select the firm who will do the work and how they will provide you with a quote. This can often depend on the scale of the project or the nature of the works involved. Your architect can advise you on alternative forms of building contracts – even the smallest works should be carried out under a simple, written agreement.

Smaller, more straightforward projects might be undertaken by someone you know or partly by yourselves. Larger or more complex projects, or ones requiring specialist skills such as underpinning or retaining walls, are more likely to involve a special procurement process known as tendering. If the works are to be tendered, your architect will need to provide much more information than if the builder had already been selected.

These are some of the things your architect will discuss with you in trying to establish a Project Budget for your building works. You are unlikely to know the answers to all of these questions but starting to consider them early on in the process is crucial. Remember, it is important for your architect to know your Project Budget as early as possible. Only then can they prepare a scheme to stay within your resources.

The list above is not exhaustive, but when considering what is included in the Project Budget, the questions above will help to frame it. Your architect will have experience of the costs of other projects they have worked on and these can be helpful as comparisons. Every project is different however and each brings its own set of constraints and demands.

If it becomes apparent your project demands more specialist cost advice, your architect will suggest you appoint a Quantity Surveyor to join the Design Team early on. Quantity Surveyors are experts in project costing and can be involved from the beginning of a project to provide initial budgeting advice, right through to the end of the project.

Ultimately, the cost of your project will be what someone is prepared to build it for. It sometimes helps to think of this the other way around. Imagine a builder is looking to “buy” a project. If they can assess the work required with the potential risks involved (by examining the project information contained in the drawings and details) and match it to their available resources, the project is worth their while. The process is then steered by the client and the architect to ensure the work is finished on time and on budget.

Find out about some of our recent projects.