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Planning Timelines and Deadlines

Planning Application Timescales

Starting a planning application can be a daunting process for many applicants and developers. Although timescales should be clear, the uncertainty of when you can expect to receive a response or decision does not help this trepidation early in the development process.

Generally, most planning applications should be determined within 8 weeks or 13 weeks, depending on their scale. Viable Placemaking have included a high-level breakdown of the types of applications and their timescales within which a decision should be made below:

Application Type


Major Application

​13 weeks​

Technical Details Consent

10 weeks

Development subject to an Environmental Impact Assessment

16 weeks

All other types of application

8 weeks

While the timescales are clear, more and more are applicants and agents seeing delays in the planning application determination process.

The Planning Guarantee

The 'Planning Guarantee' is the government's policy that no application should spend more than a year with decision-makers, including at appeal. The national Planning Practice Guidance states that this means that planning applications should be decided in no more than 26 weeks, allowing a similar period for an appeal.

Moreover, the Government's new Fee Regulations, which come into force on 6 December 2023, include a reduction in the planning guarantee period for non-major applications from 26 weeks to 16 weeks (unless exceptional circumstances apply).

Delays, Extensions, and Appeals

An article published in May 2023 by The Planner, the official magazine of the Royal Town Planning Institute, investigated how planning application delays held up developments, causing some to be abandoned. The article explained that research by the Royal Institute of British Architects found 47% of firms report projects were being delays by six months or more.

Of course, some extensions of time can be agreed as part of a planning application; however, this does not solve the issue of delays for many applicants and developers.

Moreover, delays are exacerbated when a scheme goes to appeal which are notoriously lengthy time periods.

In November 2023, the Planning Inspectorate, who determine planning appeals, updated their case timings, which are included below:

Appeal Type

Average Timescales


20 weeks

Written Reps

36 weeks


41 weeks


35 weeks

(N.b. - please note appeal timings are regularly updated and shall be subject to change. Additionally, enforcement appeal timescales may be different to planning appeals. For more information on these timeframes and to stay updated with how long appeals take, click the link here).

Viable Placemaking have extensive experience preparing and managing planning applications and appeals so understand the impact delays can have on applicants and their developments.

Recently, in liaison with Viable Placemaking, the Planning Inspectorate indicated that it was taking approximately 15 weeks to validate an appeal. This be before the consideration and determination process even begins!


Increasing build costs and general costs of development have the potential to greatly impact the viability and deliverability of a development. Any delay in a planning application can increase its costs and should be avoided if possible.

In November 2023, the ONS updated the construction output price indices. This data indicates that the cost of construction for all work has increased by approximately 5.2% in the last 12 months. Moreover, for new build housing, costs have increased by 6.3%. This is not an insignificant amount and it's extremely important that this be considered as part of the development process to ensure we can get spades in the ground.

Due to Viable Placemaking's specialism in development economics and viability, we have conducted a lot of work, including Viability Assessments and Economic Optimization Appraisals, to assist applicants and developers with the economic and viability matters surrounding their planning submissions. Delays in the planning process are one such component which can impact a scheme's deliverability.

How can Viable Placemaking help?

The main point to remember, whoever your planning team may be, is that it's important to be prepared. You should review the council's validation checklist to make sure you provide everything that's required as part of your submission to avoid prospective delays and or additional fees.

As a town planning consultancy, Viable Placemaking are acutely aware of the processes and issues which arise with many planning applications and appeals.

Viable Placemaking's staff hold professional memberships with the Royal Town Planning Institute, the Royal Institution of Chartered Surveyors, and the Institute of Economic Development. As such, we are confident that we will be able to assist with any of your queries relating to planning, development economics, and viability.

For more information or if you have any queries regarding a specific development, please don't hesitate to get in touch.


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