Extending your home is a great way to add much-needed space and increase its value. Jon from Hylands Homes shares his top tips for gaining planning permission for your home extension.

Rather than moving to a new house, obtaining planning permission for extensions can be an effective way to get the living arrangement you are after. In addition to the benefit of avoiding the upheaval of moving you may find your money goes further. When you add up the cost of stamp duty, removals costs, solicitors and estate agent fees you would be smart to put that towards making your current property perfect for you.

If extending your current home really isn’t viable due to space restrictions, then buying a property that has potential to extend might be another alternative that offers cost and time savings over trying to find a suitable home that comes to the market.

Whether you need to make a formal planning application for an extension or not will vary from case-to-case depending on a variety of factors. Let’s look at what does and doesn’t need planning permission and the main considerations you need to think about to ensure your project is a success.

Planning Basics

Technically, every extension to a home whether it is a single or 2 storey extension, loft conversion or conservatory requires planning permission. However, due to the Permitted Development (PD) rules some extensions are pre-approved as long as they meet a whole host of criteria. For instance, permitted developments rights to allow you to extend the rear of your home with a single storey extension by 3m if attached to a neighbour or 4m if detached. As of 30th May 2019, these dimensions can be doubled if you also consult your neighbours through the Neighbour Consultation Scheme. More on that can be found on the Planning Portal.

Permitted Development rights are complex to start with and to make them more complicated, are not applicable in all circumstances. Some properties or even whole areas can have Permitted Development rights removed with an Article 4 Direction imposed by the Council. You will find flats and listed buildings are also outside of the scope of PD. They also only apply to the property as it stood in 1948 or the original property if built since then. Basically, this prevents extensions from extending previous extensions. Once the PD rights on a property have been used then you will need to revert back to applying for full planning consent.

To tidy up the Permitted Development minefield a bit you can apply for a Certificate of Lawfulness to prove that your extension does come under Permitted Development. This is similar to a planning application in that the process is the same, but you will receive a notice stating that the extension does fall within Permitted Development or it doesn’t. You might think this is a pointless exercise but when you come to sell your home, solicitors will look for these documents to help expedite the selling process and a lack of this paperwork can cause delays, especially if the extension is not as clear cut as you think. With this in mind, it is Hylands Homes recommendation that you always get a certificate of lawfulness for any Permitted Development.

To find out more about whether you need an architect to do your designs read here.

Planning in designated areas
Planning Policies

For any designs that don’t fit within Permitted development then you will need to apply for a full Planning Application. In addition to the national planning policy, your Council will have a number of local policies outlining specific arrangements for your particular area that they will use to make a decision on your extension proposals.

These policies are called Local Plans and are available from the Council website. Other documents such as Neighbourhood Plan might go into more detail for your specific area within the council governed area. A good planning Consultant or Architect will likely know these policies and can advise whether your plans conflict with any of these policies.

Policies are usually more restrictive in the countryside than in urban settlements, and councils might have specific policies that apply to extensions in greenbelt land, conservation areas and areas of outstanding natural beauty (AONB). It’s likely that in these areas you won’t be able to extend as big as you can in more built up environments. The use of vague language can sometimes be utilized to allow the Council Planners scope to refuse the application. Words like “disproportionate” to the existing building are very subjective and don’t give you much of a definitive answer to what can be allowed or not. You can ask the planners what their rule of thumb is for your area during a Pre-Application Advice meeting to avoid some of the guesswork.

If your property is a terraced home or in a particularly built up area where you have close neighbours, there will usually be some extra guidance on minimum distances between boundaries, heights, sight lines and angles of view from windows that your extension should be designed within.

Listed buildings have extremely restricted policies imposed on them to preserve the property and setting as much as possible. Even if your property isn’t listed but your neighbours is, you may find that you inherit some restricted policies to preserve the overall setting.

Particularly large extensions over 100m² may be liable for a Community Infrastructure Levy (CIL) payment. Not all Councils exercise this Levy. However, if you live in your property for 3 years after completing the extension then you can claim for an exemption which is also the case for self-build projects.

Key Considerations

Planning policies tend to require that the extension blends with the existing character of the house, not dominate the street scene or overwhelm your neighbours with the proposed size. Having said that, side extensions tend to have lower ridge heights and are set back slightly from the front wall of the existing house. This makes it obvious that it is an extension rather than pretending it has always been there.

Rear extensions generally have greater flexibility because their impact is much less on the street scene and neighbouring properties. Typically, materials and design will blend in with existing finishes but in some cases, you might find that the planners are happy for you to build something modern to showcase the difference between contrasting construction methods.

While your neighbours aren’t entitled to a view they are entitled to light and no reduction in their privacy. We have found the best approach is to show them your plans before you submit them to the Council and get some feedback. You might not implement any of their suggestions, but it is good practice to try and get them on side, so it isn’t a surprise when they receive a planning notice through their door outlining your proposals. Neighbours tend to object when they haven’t been consulted first as they see the application as a faceless problem they can shout about. On the other hand, even if you don’t receive any objections doesn’t necessarily mean the Council will pass the plans.

Another consideration is the impact of your extension or on the environment around it. Trees on your land or on neighbouring land can pose a problem. An arboricultural survey is usually needed to outline the impact that the trees and extension will have on each other. Tree Preservation Orders (TPOs) are particularly difficult to navigate around with planners wanting to implement root protection zones that foundations cannot enter. Also, trees that have a TPO on them will need Planning permission to be removed or even trimmed so bear that in mind if you have any TPOs surrounding your property. Green areas that form part of the street scene can be a particularly sensitive issue that may need addressing in your design and access statement.

Wildlife and protected species found on your land may have an impact on the level of extension you are able to do, or you may need to propose ways to mitigate the damage caused to these habitats. Animals such as bats, great crested newts or badgers may be present, and an ecological survey will be needed to identify possible solutions.

While the presence of sewers and drains isn’t a planning issue, they could influence house layout and/or the cost. A build over or diversion agreement may be needed if drains are impacted by your proposals.

Planning permission strategies
Planning Tactics

If your plans are pushing the limits of what Planning Permission will allow then there are various strategies to increase the probability of getting the planning permission you want. They might seem a bit long winded but sometimes you just have to play the long game to win.

Door in the face 
Applying for something oversized to start with fully expecting to be refused and subsequently reducing it down to your original idea can help set the expectations of the planner higher than normal.

Thin end of the wedge 
On the contrary, getting approval for something smaller and then applying to enlarge it can work. Adding on another 300mm or 600mm to the depth of an approved plan is difficult to prove as a harmful addition that should be refused.

Lesser of 2 evils
You could apply for a certificate of lawfulness for the biggest ugliest scheme under your Permitted Development rights and then submit your full planning proposals for your beautifully designed extension and point out that if planning is refused then you’ll revert to your PD plans. Of course, this is a bluff, but it’ll help focus your planning officer to avoid refusing your plans.