The Checks to Make Before You Start Your Project

It’s only natural that a homeowner's primary focus when planning an extension is on the aesthetics and the additional space their project will create – but checking the planning route should be the first priority. 

Indeed, that initial assessment shapes the entire project – from its physical dimensions to its overall design direction.

Not every extension needs full planning permission; many fall under permitted development. 

But, because the right answer depends on your specific property and site, making assumptions is risky – it can lead to expensive revisions if your drawings don't align with local regulations.

We treat this stage as the project's foundation, ensuring every design choice is grounded in reality. By identifying constraints early, we create a more efficient process – leaving your project better prepared for the next stages of development.

Check whether permitted development applies

The importance of a detailed proposal 

Permitted development rights allow certain types of work to go ahead without a full planning application. Many rear extensions and loft conversions can fall within this category, but the limits are specific. Height, depth, materials, proximity to boundaries and previous alterations can all affect the outcome.

It’s also important to know that not every property benefits from the same rights. Flats and maisonettes are treated differently from houses; and some homes have had permitted development rights restricted or removed through planning conditions. 

That is why online searches or a quick comparison with neighbouring properties rarely gives enough certainty.

If a project is intended to follow the permitted development route, the design should be shaped around those conditions from the outset. If the proposal falls outside those limits, it is better to know at the earliest possible stage and prepare for a full application, with the project designed accordingly.

Local constraints around the property

The wider planning context can change what is likely to be approved

The property's location can have a major effect on the planning position. Conservation areas, listed buildings, green belt locations and flood zones all bring additional planning considerations. Constraints such as these can influence the form of the extension, the materials used and the level of supporting information needed with an application.

A house in a conservation area may need a more sensitive design response; a listed building will usually involve a much more detailed heritage-governed approach. Green belt sites often bring policy considerations around scale and openness. Flood risk can also affect what is suitable on the plot.

Local knowledge, then, is especially useful. Maidenhead Planning works across Maidenhead and the surrounding area, helping homeowners understand the planning conditions that may apply before they invest in detailed design work.

Be clear about the problem you want the extension to solve

A successful project begins with a clear brief

Before moving into the drawing stage, it’s worthwhile to step back and ask what the project needs to achieve. More room is a common goal, but the real issue may be poor layout, lack of storage, weak connection to the garden, or an underused loft or garage. A strong, detailed brief leads to better design decisions and more purposeful planning advice.

Some households benefit from an extension, others may get better results from reconfiguring the existing footprint or converting part of the house already there – which is exactly why early conversations are so valuable. They help define the problem clearly and shape the response around the home, the budget and the planning position.

Think beyond planning permission

Approval is only one step in the wider project

Even when planning permission is not required, or once approval has been secured, there is still more to prepare before building can begin. 

Technical drawings, building regulations, structural input, and contractor pricing all need to be properly coordinated. Early expert advice helps link the key stages, so the project moves forward in a more organised way.

For homeowners, a joined-up approach typically makes the process far easier to manage; you gain a clearer view of what is involved, the order in which things should happen, and where specialist input is needed.

A project with more clarity and direction

Before paying for extension drawings, it is worth checking whether permitted development applies, reviewing any site constraints and making sure the project brief is clearly defined. Those steps can save time, reduce unnecessary revisions and help the design move forward on a sound footing.

Every property brings its own considerations, so location and project-specific advice from an expert is always of benefit. If you are planning an extension in Maidenhead or the surrounding area, Maidenhead Planning can help you understand the planning route and the key checks to make before design work begins.

If you are considering a house extension and want clear advice before committing to drawings, book a free consultation with Maidenhead Planning to discuss your project.

Talk to Us About Your Planning Permission Needs