Part 3: How Much Will My Extension Cost

Early-stage cost input can be a really useful way to start getting a rough idea of what the build cost will be.

Feedback From Builders

The main downside with attempting to price too soon is that you won’t have finalised everything at this stage so there will be assumptions made. However, if you can encourage a handful of builders to give you some feedback that’s still a useful starting point, just ensure you understand what is excluded.

They will likely be giving you an indication for the shell of the building, not necessarily the glazing, finishes, landscaping etc. And remember, material and labour prices change, treat this as a rough estimate. 

Understand Your Specification Choices

With your ballpark figure in mind, it’s important to understand that your specification choices later on down the line will impact the overall project cost. Do you choose the £10,000 windows or do you prefer the look of the £20,000 windows? You get my drift.

Square meter rates have their place but only as a VERY broad guide. Other alternatives for early-stage cost planning, and for cost control throughout the whole project, include appointing a quantity surveyor. And whilst this isn’t commonplace on smaller projects, it’s certainly something to consider if your project is particularly complex. 

Click here to read Part 4: Saving costs on an extension