B1 Office to C3 Residential Use Prior Approval Determination
Case study

B1 Office to C3 Residential Use Prior Approval Determination

In February 2016 we were appointed to prepare a report assessing the transport & highways and flooding impacts of a prior approval determination application to convert an office building in Swindon to residential use.

Transport Planning
Infrastructure Design
Environmental Assessment

Details

Project

Following recent changes to 'permitted development' categories introduced by the Town and Country Planning (General Permitted Development) (England) Order 2015, the development proposals involved a "Class O" development where conversion is proposed from an existing Class B1(a) (office) to Class C3 (dwelling houses).

The proposals comprised the conversion of approximately 6,222sqm of existing B1 office use to provide 100 residential apartments.

Challenge

Where consideration of any transport and highway impacts or flooding risks are requested by a Local Planning Authority, further clarification of these requirements are provided within Paragraph W 'Procedure for applications for prior approval under Part 3' of the General Permitted Development Order 2015, which states:

"Where the application relates to prior approval as to transport and highways impacts of the development, on receipt of the application, where in the opinion of the local planning authority the development is likely to result in a material increase or a material change in the character of traffic in the vicinity of the site, the local planning authority must consult -

  • (a) where the increase or change relates to traffic entering or leaving a trunk road, the highway authority for the trunk road;
  • (b) the local highway authority, where the increase or change relates to traffic entering or leaving a classified road or proposed highway, except where the local planning authority is the local highway authority; and
  • (c) the operator of the network which includes or consists of the railway in question, and the Secretary of State for Transport, where the increase or change relates to traffic using a level crossing over a railway."

(General Permitted Development Order 2015, Paragraph W(5), Page 47)

"Where the application relates to prior approval as to the flooding risks on the site, on receipt of the application, the local planning authority must consult the Environment Agency(b) where the development is -

  • (a) in an area within Flood Zone 2 or Flood Zone 3; or
  • (b) in an area within Flood Zone 1 which has critical drainage problems and which has been notified to the local planning authority by the Environment Agency for the purpose of paragraph (zc)(ii) in the Table in Schedule 4 to the Procedure Order."

(General Permitted Development Order 2015, Paragraph W(6), Page 48)

Solution

Our report clearly demonstrated that the proposals would have no material impact on trunk roads or on local rail infrastructure and assessed the traffic impact of the proposals. It was found that the conversion of approximately 6,222sqm of existing B1 office use to provide 100 residential apartments would result in a significant reduction of vehicle trip generation during the weekday peak periods and throughout the day. It was concluded that the proposed development would not result in a material increase or a detrimental change in the character of traffic entering or leaving a classified road or the highway network in the vicinity of the site, and was not therefore subject to requirement N(5)(b) of General Permitted Development Order 2015.

Following input from the Design team, our report also concluded that the site would not be at risk of flooding from fluvial sources because it is located in a low risk Flood Zone 1.

In summary, out report established that:

  • The site is accessible by non-car modes of transport
  • The proposed development provides sufficient parking
  • The proposed residential development will have a beneficial impact on the existing operation of the local highway network
  • The site would not be at risk of flooding from fluvial sources because the site is located in a Flood Zone 1 area indicating a low risk of flooding
  • The site would not alter the surface water arrangements of the existing site and will not increase the risk of flooding to itself or surrounding properties

The development proposals were therefore considered to be wholly acceptable in transportation planning and flood risk terms and, if necessary, met the transport, highways and flooding requirements for "Prior Approval" as defined within the General Permitted Development Order 2015.

Following the submission of our findings to Swindon Borough Council (SBC), SBC Highways requested further information be provided regarding the proposed servicing and cycle parking arrangements. These details were provided and were supported by refuse vehicle swept path analysis drawings provided by Mayer Brown.

After reviewing the highways and flood risk information provided, SBC were happy to confirm that Prior Approval from the Council (i.e. a Planning Application) was not required.

For further details please contact pstocker@mayerbrown.co.uk


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