FAQs

About The Practical Planning Company

Permitted development and planning permission

Building control and technical questions

The build

What do your fixed fees include?

Our fixed-fee contract covers your initial site survey, initial drawings and design, planning permission submission (if applicable), building control submission, up to three revisions at the discretion of the designer and approved drawings, ready to hand to your builder.

Additional costs include building control, your planning permission fee, structural engineer costs and build over agreement fees - all of these are payable to third parties, and not us. A sensible way to budget for this is to assume around 5-10% of your build cost will be spent on your plans and approvals. For example, if your project is going to cost £30,000 you can expect £1,500-£3,000 to be spent before you’ve started building.

Our additional fees would include extra revisions to your plans and site visits, if necessary.

How long does the entire process take?

Hopefully not too long! For a permitted development extension. it would be around three weeks until you’re holding your approved drawings in your hands, ready to give to your builder. For works requiring planning permission, if everything goes smoothly, it would take around 14 weeks until you receive drawings ready to build.

What are permitted development (PD) rights?

According to the Department for Communities and Local Government, “permitted development rights allow householders to improve and extend their homes without the need to apply for planning permission where that would be out of proportion with the impact of works carried out.”

Put simply, everyone in England has the right to add to and improve their property as long as the work meets certain criteria.

A full list of permitted development rights can be found here but if you’re looking for something simpler, take a look at the Planning Portal, which has a number of helpful guides.

Do I need planning permission?

You can extend or improve your home in various ways without having to go through the 8-10 week planning process. To look at your permitted development options, click here. If your extension comes outside of your PD rights then you may need planning permission. Find out more here.

Do I have permitted development rights?

Most likely, yes. But, some homes - primarily new builds (less than two years old), listed properties and buildings located in a conservation area - have their permitted development rights withdrawn and will require full planning permission for any kind of home extension. In some cases, the permitted development rights may just be limited.

Also, keep in mind that PD rights only apply to the original dwelling - if a past owner has already added an extension of some kind, this will count towards your permitted development allocation. And, if you live in a flat or maisonette, you won’t have any PD rights.

I’ve found out I need planning permission - how much is the council’s fee?

The planning fee is currently around £206 (plus administration charges) for standard enlargement, improvement or alteration work. Please note, the fee is significantly more for new builds and flat conversions.

What is the planning process and how long does it take?

The planning process is typically 8-10 weeks, depending on how busy the council is and it can take the planners up to two weeks to validate the application. Once the application is validated, you will be given a decision date. Within the 8-10 week period, there will be a consultation phase where your neighbours’ views will be considered.

During the process, the planner may raise concerns about your planned works and will let you, and us as the agent, know. We can then alter your drawings as per the planner’s recommendation or request, which is included in your fixed fee.

I have planning permission from two years ago - how can I get my build started?

Good news! As long as the planning permission you previously acquired is no older than three years, you don’t need to reapply. But, if your previous architect didn’t produce technical drawings then you essentially have to start from square one - sorry!

We will come out and measure your property, redraw your house and extension to match your previous architect’s work and then produce your technical drawings. Then we will get them registered with building control and send them to you once they are approved.

My planning permission has been rejected - what can I do now?

If the planners refuse your application you will be given another chance to change your drawings and reapply for planning permission. The council will not charge you a planning fee for this application as long as it is done within one year of the first one.

We would charge an hourly rate to redesign the drawings and resubmit them.

Does my new extension have to be constructed in the same material as my existing house?

Most planners prefer your extension to match your existing property materials. It is also a requirement of permitted development. Doing this is fairly simple: take a photo of your bricks or tiles and send them to a builders merchant such as Jewsons or Travis Perkins. They will then tell you the closest brick match they have. Remember the guidelines are materials to match existing or as close as possible.

I want to change the size of the rooms in my new extension - do I need to reapply for planning permission?

No. Any internal changes would not affect the planning permission you’ve already been granted.

What’s the difference between prior notification and planning permission?

Notification for Prior Approval for a Proposed Larger Home Extension - prior notification for short - allows homeowners to build larger extensions (up to six metres on a terraced/semi-detached and up to eight metres on a detached property) under permitted development. The rights were first introduced in 2013, but made permanent in May 2019. Learn more about the scheme here.

Although it comes under PD, it involves notifying the local planning authority prior to development taking place so that neighbours can be consulted. Your neighbours may object, but that doesn’t mean the application’s going to get refused.

In brief, there doesn’t appear to be much difference between prior notification and an application for planning permission. In fact, it can take almost as long as one to be accepted, and the recently introduced fee is not much cheaper!

What is building control and do I need it?

Building control is a set of rules and regulations that ensures your extension is built to the correct specification. An approved inspector will visit your site at key stages during the build and ensure it is being built correctly.

And yes, all homeowners require a building control officer to inspect any building work and issue a completion certificate.

How much does building control cost?

Building control costs vary depending on the size and complexity of your building work. Prices typically start at £450 + VAT for a garage conversion and go up from there. Single storey extensions are around £500+VAT and double storey are around £650+VAT.

What are my options for building control?

There are more and more private building control companies emerging every year. Each one has qualified inspectors that will work with your builder to ensure you get your completion certificate. There is also your local authority’s building control department who will ensure you get your completion certificate as well, though please bear in mind that this can often take longer than using a private company.

Do I need a structural engineer and how much would one cost?

If you are creating an opening that is more than three metres or one that is close to a key structural element (lintels or corners) then yes, you will need an engineer to produce structural calculations.

Structural calculation costs vary from project to project, and from engineer to engineer. From our experience, they typically start at around £150 + VAT for a single steel beam. An average cost for a single storey extension to create one open space room is around £550 + VAT.

I’ve received a build over agreement form from my water authority - what is it?

A build over agreement is simply a form you need to fill in and send back to your water authority for approval. Essentially you’re telling the water authority that you are going to build over a public waste pipe and whilst doing so you’re going to properly protect it.

I’ve got a manhole in my garden where my new extension will go, do I need to move it?

Yes. This is usually a simple job as long as your drains are less than one metre deep. We will note down any manhole locations on your drawings and give you as much information as we can on how to build over them and relocate them.

Do you show pipes and light switches on your drawings?

No. We provide all the detail your electrician and plumber will need to carry out their work but it is up to you to work with them to discuss socket locations etc. Most builders will quote based on a certain number of sockets, radiators and lights.

My builder wants to use their own building control company, where do I stand?

We will not release drawings until they have been plan checked - this is so there can be no mistakes on site due to working from incorrect plans. But, this means you cannot get quotes from builders until you have registered your project with building control. If your builder wants to use another building control company then you will lose the money you have paid for your plan check. We recommend you tell your builder which building control company you are using as the regulations are the same nationwide and the service is always similar. And remember - it’s your choice, not your builder’s!

I’ve got my final plans in the post, now what?

During the design process we will discuss your building options - whether it is a self-build or you’re getting a builder in to complete the work. Your drawings are the best tool you can have to get accurate quotes from builders and we provide digital copies as part of your package, so simply email them out and see what comes back.

Once you’ve got your builder, you’re all set!

My builder wants to go off the plans and make some changes - is this okay?

Your builder might suggest a cheaper option - or an option they prefer - and in most cases, internal changes are fine and won’t affect your structure. These can be completed on site and agreed with your building control officer.

Any changes you require to drawings after completion of our contract would be completed at the discretion of the designer. Minor amends would typically be charged at an hourly rate, but a new contract would be required for larger changes.

My builder has come across a problem on site, can you come out and have a look?

Yes. We are more than happy to come out and see you on site, however we do have a flat rate of £100 for extra site visits. Most issues can be resolved over the phone, though, and we’re more than happy to talk to your builder - just get them to give us a call.

I’ve had quotes back from builders and can’t afford to build my extension - can I have my money back?

Sorry, but no. We have been asked to provide a service and have done the work as you have requested. You will have a copy of the drawings that you have paid for.

We will do our best to guide you on budget during our design meetings and can provide rough estimates based on square footage, but builders can unfortunately charge what they like and we can’t do anything about that.

We’re a family business, and have been at the mercy of builders during our own home extension work - we’d be happy to share our experience with you if it helps. We would advise before embarking on a project with any architectural design company, that you seek guidance from builders, to get ballpark figures, and if additional borrowing is the route you’re going down in terms of funding, we suggest you speak to mortgage advisers as well to double check it is something you can definitely afford.

How can I reduce the cost of my build?

There are many different cost-saving measures to consider including:

1. Use classic French doors (‘patio doors’) instead of folding doors. Modern bifold doors are becoming more popular as they bring a lot more light into the home and provide a more attractive view of your outdoor space, potentially adding value to your property, but French doors are generally more affordable and easy to install.

2. If you’re using steel beams, incorporate nibs (structural concrete columns) into the design rather than making them flush. If you do the latter, you’ll need steel columns instead and these are very expensive to install!

3. Build using block and render, instead of bricks. With the cost of bricks averaging around £1 per brick, concrete blocks at 50p per block and six bricks to a block, it’s easy to see how much of a difference this can make on the overall cost of the build. But, remember, you should ideally match your materials to the existing and rendering may require planning permission, depending on where you live and the type of property you have. It’s a great way to save money, though.

4. Go for a flat roof instead of pitched. While a pitched roof is more traditional and versatile, and offer longevity and durability when compared with flat roofs, the initial cost of construction can be much higher. Plus, you can get better light in through a flat roof with a lantern than a pitched roof with velux.

Obviously, these tips will all affect the aesthetic and it’s important that you' feel pleased with the end result - you’ve got to live in it! So don’t compromise your happiness to save a bit of cash. Always speak to your designer as they will have a few different ideas about how to save money in the design, that you may have missed.

And don’t forget the most obvious one - pick up a shovel and get stuck in yourself!