Frequently asked questions

Please find below the answers to some commonly asked questions. If you require further information about any aspect of our service, then please don't hesitate to contact us.

About Sevenoaks Plans

We have the experience to see your project successfully through to completion. We can oversee the design, assist with the approvals process, manage the build and keep track of your budget.

Consulting us at the earliest state will alllow us to gain a real feel for your needs so that together we can establish a clear brief and a realistic budget. This will help reduce the overall design costs and help minimise any potential problems early on.

Our initial consultation is free...
Generally we charge approximately: 
  • £1400 for a ground floor extension
  • £2400 for a 2 storey extension
  • £800 for a porch
  • £950 for a house design refurbishment
  • £1300 for a loft conversion
 These are all subsequent to surveys. These charges all include planning services, building control services, design liaison and construction drawings.

During the initial visit your architect will spend time asking you questions and finding out what you want to achieve. They will discuss the options that you have available along with the feasibility and implications of these options.

They will then take measurements of your property and sketch out a plan of your property as it currently exists. Once this is completed we are now in a position to draw up initial design sketches to help you visualise your design and provide input.These drawings will be yours to keep so that you can refer back to them at a later date.

The initial visit is designed to be an interactive session so you will be heavily involved in the process providing information about your lifestyle, your ideas and your feedback on proposed solutions.

By the end of the initial visit you should be fully informed and in a position to move forward with your project. 

Planning / Building control

Planning permission is required for building work so that the local Council can keep control over development in the area. 
If you are a householder, you may be able to extend your home under Permitted Development rights without gaining planning permission. This varies by the type of house you have, your proximity to neighbours and the effect it may have on them. Using Permitted Development rights to extend your property does however limit the type of extension you can have.
Building Regulations plans approval is required to administer the Building standards - this covers the functional requirements of buildings to safeguard the health and safety of the people using them, energy conservation, access and convenience for people with disabilities
Planning approval and Building regulation approval is usually valid for three years – both of which can be extended. We recommended that all approvals are obtained prior to work commencing at your property. 
You will find more detailed information on the above on your local Council’s website. 
We can help with the approvals required before your project can go ahead, including preparation of applications to the Local Authority for planning consent (where needed) and for Building Regulations plans approval (which covers the functional requirements of buildings to safeguard the health and safety of the people using them, energy conservation, access and convenience for people with disabilities).

For domestic properties, planning consent or permission relates to changes in the appearance or use of buildings such as an extension to a house, or a conversion of a house into flats.

Planning should not be confused with the Building Regulations that are entirely separate  and are covered by other FAQs.

Planning can be one of the main hurdles to clear when thinking about making changes to your home and needs to be given consideration from the start. It may be possible that your project can be done within Permitted Development – we will be able to advise you of this during your initial visit.

A common misconception is that because other houses in the street have, for instance, roof extensions, this will automatically mean that yours will be allowed. This is not always the case as planning policy does change over time. Your architect will be able to give you advice relating to current planning policy that will help develop the design solution.

Building regulations

Not to be confused with Planning, Building Regulations are there to ensure that buildings are made to a minimum quality standard for such things as structure, fire escape, drainage, ventilation, insulation and so on.

The regulations can often seem unreasonable, but they are all there for good reasons.

Building Regulation matters are usually handled by Building Control Officers in the Building Control Department of your Local Authority but increasingly private licenced inspectors are an alternative.

Unlike planning, there is no committee and you should not have a long wait for approval.




There are two ways of applying for Building Regulations approval: the Full Plans method or the Building notice method.


The Full Plans method of application is more involved as it requires the submission up-front of detailed drawings that show a great deal of information, such as the fire escape routes, ventilation capacities, for instance. Many people find this somewhat 'over the top' for a domestic project. However we can produce the full plans for you if you, in consultation with your architect or your builder, feel that this is the preferred route.

Most people find that a Building Notice is the simplest and most appropriate for alterations or extensions to domestic properties.

You should not need specific drawings for this and your builder can look after the process on your behalf while undertaking the works. To do this the builder simply completes a Building Notice form and submits it to the Building Control Department - this has to be done at least 48 hours before work starts on site.

There is a fee to pay - your Local Authority can provide the information.

Once the work starts, the Building Control Officer will visit the site and make arrangements with the builder to visit at specific points through the progress of the works to check that the works are up to the minimum standard that the regulations require. He/She may also request supplementary drawings and information. When the works are complete, you can ask the Building Control Officer to give you a certificate to confirm that everything has been done to the required level. 

It's a good idea to obtain this certificate as proof that the work has been done well, particularly if you're likely to want to sell your property eventually.

Permitted Development

For small extensions and alterations, your proposals may fall within your Permitted Development Rights which means that planning permission will not be necessary.

There are a number of limits on height, volume (in cubic metres) etc. that your proposals need to be within for Permitted Development to apply.

If your project is eligible for Permitted Development we would recommend that you apply for a Certificate of Lawful Development to confirm this. The application needs to be supported by suitable drawings and calculations and Sevenoaks Plans can help you with this.

Party Wall agreements

If you're planning to do work to a domestic propert with an adjoining wall to another property then your project may well fall under the Party Wall Act.

Works that affect a wall, fence or any part of your neighbour's structure, within certain specified distances will require notification to adjoining owners in accordance with the Party Wall Act 1996.

This notification can be a complicated procedure and can take a good deal of time. We recommend that if you might have an issue with Party Wall legislation, you approach a Party Wall Surveyor who will be able to advise you and guide you through the process.



Conservation plannning

Buildings of particular architectural interest are often officially Listed and thereby protected. Many residential buildings are listed Grade 2 which means that all alterations (not just those to the outside or original parts) have to be approved under Listed Building Consent. Making a Listed Building Consent application is similar to making a planning application - but with a few differences. The process may be handled by a conservation officer within your local planning department or might be referred to English Heritage and there is no application fee. As with standard planning permissions we can help you with this. 

Living in a Conservation area usually means that changes to the external appearance of your building will be a particularly sensitive issue. You will probably need to complete an application for Conservation Area Consent. Again, it is advisable to check with your local planning department or ask us to do this for you.

Selecting and working with a builder

The scheme-level drawings will form the backbone of the information your builder will need. However you will need to go through the drawings with your builder and architect before works start to agree the appropriate level of detail. Many builders do not need full detail drawings in order to build standard building elements. If the design contains elements that are particularly complex or unusual, it is sensible to get us prepare detail drawings of these elements. If you want more things added to the drawings or any additional help we are here to help you through the process.

We work with local builders that we know and trust. We're more than happy to arrange a meeting between a builder and prospective client even before you've decided to work with us. 
When selecting a builder, always ask for recommendations - either from friends or relatives or from reliable sources such as the Which? Trusted Trader scheme.
Once you've made a short-list then contact them for references and always follow these up, even if the builder has come highly recommended. We are happy to assist you in this process if you wish.

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