A significant proportion of the budget for your renovation project will be on professional fees and application costs. The great news is some of the fees may not apply to you depending on the work you are carrying out.

We have covered the most common fees that you are likely to pay, however remember that the costs will vary depending on your location in the country and size of the project – so this is only a guide!

Professional Fees

Planning Permission Drawings Cost

For an average extension or conversion with a build cost of around £30,000 – £40,000 you should budget around £1,000 – £2,500 for planning permission drawings. The price varies depending on the design requirement, the scale and complexity of the project. You may spend even more than the upper limit if you need inspiration on your project or want a real design makeover and engage with a high-end designer.

See our guide on who is best to complete your drawings and where you can make savings.

Building Regulations Drawings Cost

Some architect firms will include building regulations drawings and structural calculations in the planning permission cost above, so be very clear at the outset what has been included.

For a small extension, fees for stand alone building regulations drawings and calculations will start from £500 and be as much as £1,400.

If you have a good idea of your layout then you can save a significant amount by working directly with a structural engineer rather than both an architect and structural engineer.

Party Wall Application Fees

The Party Wall (etc.) Act 1996¹ applies to a large proportion of extensions and renovation projects. If you plan to do work to a party wall, excavate near another building, or build on the boundary line then it may apply to your project. Your architect or surveyor can serve notice for you with the fee to be likely under £100, but you can serve notice yourself and save on these costs.

If your neighbour does dissent the notice, then you must appoint a surveyor. Ideally your neighbour agrees to the same surveyor for both properties which will keep costs down, typically costing around £800-900 per surveyor.

Try and avoid the costs of the surveyor by keeping your neighbour informed from the outset so they are less likely to dissent.

Make sure you have considered all of the fees to achieving your dream kitchen

Application Fees

In addition to any professional costs, you will need to budget accordingly for some of the following application costs:

Planning Permission Application Fees

The cost for the planning application for an extension will be £172² for a Full Planning Application, or £86 for a Lawful Development Certificate, which is appropriate where you think you may not need planning permission but want to be certain.

Before you embark on preparing the planning permission drawings and submitting the fees, do check whether you actually need planning permission for your project – a surprising number of extensions and conversions don’t require planning!

Building Regulation Application Fees

Building Control fees are around £300 – £900 depending on the size of the project, your local authority and number of dwellings in the property.

You can make some savings hiring a tradesperson who is registered under the competent person scheme – they will self certify their work complies with the Building Regulations instead of having to submit a building notice. Many kinds of work can be self certified such as replacing windows or replacing the boiler however an extension or renovation will require a submission.

An example of building regulations drawings

Are there any other costs?

There are some other areas you may wish to budget for depending on your project, which might include:

  • If you are carrying a large renovation on a run down property it is worthwhile appointing a surveyor at the outset to identify any structural issues that you may otherwise overlook.
  • You may like a contract drawn up with your builder if you are taking on a large project. You can either use a standard template (around £20) or appoint a solicitor to create a bespoke contract for you, although this will be costly.
  • You can hire a professional such as your architect or designer to project manage the renovation end to end, including ordering the materials. This is often charged at a percentage of the overall project. Many good builders will project manage the build for you though so chat to them to confirm what they will do and what you can do together.
  • Flood risk assessments or anything specialist for your property.
  • If you are converting to flats, or changing the use of the building then you will need to apply for a Change of Use Application.

A final word….

Before you agree to any professional fees, confirm what the quote includes. Many architects or structural engineers will submit your plans for you as part of their fee, but do check as this may be an additional cost!
¹The Party Wall Act only applies in England & Wales. In Scotland and Northern Ireland, boundary rules apply.

²Note these are the cost in England and they vary slightly throughout the rest of the UK.