When Milton Keynes homeowners first start thinking seriously about a home extension one question comes up almost every time. Do I need planning permission? It is a completely natural thing to wonder and the answer depends on a handful of specific factors that are worth understanding before you start approaching builders.
At Crownhill Building Services we have been delivering home extensions across Milton Keynes for over twenty years. In that time we have guided hundreds of clients through the approval process — from straightforward Permitted Development cases through to full planning applications in conservation areas. Here is what you need to know.
What Is Permitted Development?
Permitted Development is a set of rights defined by the UK government that allow you to extend or alter your home without submitting a planning application to Milton Keynes City Council. The majority of single storey rear extensions fall within these rights and require no additional consent whatsoever.
For home extensions in Milton Keynes the key Permitted Development rules are as follows.
A single storey rear extension can project a maximum of 3 metres beyond the rear wall of a terraced or semi-detached house and 4 metres for a detached property. If you want to go further than those limits — up to 6 metres for a terraced or semi and 8 metres for a detached — this is achievable through a Prior Approval scheme which is a considerably lighter process than a full planning application.
The height of a single storey rear extension must not exceed 4 metres. Where the extension falls within 2 metres of a boundary the maximum permitted height reduces to 3 metres.
The combined footprint of all extensions must not cover more than 50 percent of the land surrounding the original house.
When Is Full Planning Permission Required?
There are specific situations where Permitted Development does not apply and a full application to Milton Keynes City Council becomes necessary.
If your property sits within a Listed Building or a designated Conservation Area the rules are considerably stricter. Milton Keynes has a number of such areas. Parts of Newport Pagnell old Bletchley and Woughton on the Green are designated zones where external alterations require formal consent regardless of the size of the proposed extension.
If your Permitted Development rights were removed by the original developer at the point of sale — something that happens on certain new-build estates across MK — you will need to check your title deeds or contact the planning department directly to establish your position.
If you are planning a two storey side or front extension a full planning application is almost always required.
If the proposed extension would cover more than half of your plot planning permission is needed regardless of height or position.
What Is Prior Approval and When Does It Apply?
Prior Approval sits between Permitted Development and a full planning application. It comes into play when you want to build a larger single storey rear extension — between 3 and 6 metres for a terraced or semi-detached house or between 4 and 8 metres for a detached property.
Milton Keynes City Council notifies neighbouring properties and allows 21 days for objections to be raised. Where no material objections come forward Prior Approval is granted automatically. The process typically takes six to eight weeks from submission through to decision.
How Crownhill Building Services Manages This For You
We handle all documentation and approvals from the very start. Our team checks your Permitted Development position submits Prior Approval or a full planning application where required and carries the project through Building Control right through to completion. None of our clients go through this process alone.
With over twenty years of experience delivering home extensions across MK we understand the local requirements and the typical concerns that arise in each area — from Wolverton and Newport Pagnell through to Bletchley and Westcroft. That knowledge saves time and removes uncertainty from the process.
If you would like to find out whether your proposed extension falls within Permitted Development get in touch for a free consultation. We will give you a straight answer without the jargon. You can also find out more about how we work or take a look at our portfolio of completed projects across Milton Keynes.