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Planning a home extension usually starts with an idea. Maybe you want a bigger kitchen, another bedroom or simply more space for the family. Then the practical questions start to appear. How much will it actually cost? Can you afford the design you have in mind? And when is the right time to find out?
The good news is that you do not have to wait until your Building Regulations drawings are finished to start thinking about costs. Getting the right level of cost advice at different points in the project can help you make sensible decisions before things go too far.
Stage 1: Get a Budget Estimate Before Planning
The first stage is about getting a general idea of what your project could cost.
An initial budget estimate is useful before you submit a planning application. At this point, your plans may still be fairly early, but you probably have a good idea of what you want to achieve.
Having a headline cost range gives you a chance to stop and think, like:
- Does the project fit your budget?
- Are your plans realistic?
- Would it be worth changing the size or specification before moving ahead?
Finding this out early can save a lot of frustration later. There is little point in getting attached to a design only to discover that the likely build cost is well beyond what you wanted to spend.
Stage 2: Understand Where Your Money Is Going
As your design develops, the numbers can become more useful too.
A Budget Cost Plan gives you a clearer breakdown of the likely costs across the project. Rather than looking at one overall figure, you can start to see where the money is going.
This can be helpful when making design choices. Perhaps you want to spend more on the kitchen but are happy to keep other finishes simpler. Seeing the costs in more detail gives you something practical to work with.
It also means you can make these decisions while there is still room to change the design.
Stage 3: Get Detailed Before You Build
Once your Building Regulations drawings are complete, you are in a much better position to understand the likely final cost.
A Detailed Cost Plan can provide a more accurate picture of where a builder’s pricing is likely to land. It can also highlight opportunities for value engineering.
That does not simply mean cutting costs. It is about looking carefully at the project and deciding where it makes sense to save, where spending a little more could be worthwhile and what changes could give you better value overall.
