Agenda item

Paul Smith, Head of Development Management, presented the report on the interim draft guidance for applicants in dealing with the submission of planning applications including basement development. Mr Smith advised the Committee that paragraph 1 of the report should be amended to read “For Planning Sub-Committee to consider and note…”. Mr Smith advised that the list of appendices on page 7 of the agenda pack should be amended to include appendix 9 “CPG4 Basements and Lightwells” and appendix 10 “Barnet – Design Guidance No.5”. Mr Smith advised that the report had been amended in respect of the mandatory conditions, such that the Hydrological and Hydro-Geological Condition as set out at paragraph 20, on page 27 of the agenda pack, would apply to applications of Type 2, as well as Types 3 and 4. Mr Smith advised that in relation to cumulative development, on page 29, the definition should read “where two or more basements adjacent to one another, or in close proximity, are proposed or already exist (including a nearby neighbouring street if the construction is close to a corner junction where more than one site in any one street is under construction at any one point in time)”.

The committee asked whether there was any difference in the guidance relating to Basement Impact Assessment (BIA) between Haringey and Camden, when the special condition in relation to monitoring by engineer would be applied, and whether there was any guidance on whether a local authority could be sued in the event that someone’s land was damaged as a result of permission being granted for a neighbouring basement development. Allan Ledden, Legal Officer, advised that the relevant case was that of Murphy v Brentwood District Council 1991, where the House of Lords determined that there was no liability on the grounds that the loss caused was pure economic loss. Mr Ledden advised that the circumstances posited by the Committee were very similar, and that any such claim would be unlikely to succeed on the same basis. There was a range of other legislation in place to protect homeowners. Officers advised that the Haringey guidance was largely based on the Camden guidance, but that Haringey guidance did differ from Camden in respect of the information required at validation stage, as the Haringey guidance only proposed that a BIA was required at this stage for type 4 applications. This was on the risk-based assessment that all attached conditions needed to be satisfied before a development could proceed, and that requiring further information from applicants at an early stage for other types of application would be an additional financial burden on the applicants. Monitoring by Engineer was a condition which could be added where the Committee felt that this was required, and it was noted that this condition had been applied in respect of the Channing School application.

In response to a further question from the Committee, it was confirmed that hydrological and hydro-geological surveys would be based on trial holes on site as a minimum, and would not be purely desk-based. Marc Dorfman, Assistant Director, Planning, Regeneration and Economy, reported that for applications of type 4, a BIA would be required at validation stage. The Committee asked where information on existing basements in the area might be found, and Mr Dorfman advised that the planning and building control records were available for inspection, and that planning officers would be able to assist with any such enquiries.

The Chair permitted Gail Waldman from the Highgate Society and Professor Tony Wright, a local resident, to address the Committee on this item. Ms Waldman stated that the Highgate Society had raised issues regarding the impact of such development on neighbouring properties, and welcomed the suggestion that type 2 applications should now also be subject to hydrological and hydro-geological survey as a condition. Ms Waldman advised that the Party Wall Act was not intended to address issues of groundwater flow and soil erosion and should not be relied on for that purpose. Boroughs such as Kensington and Chelsea, Westminster and Camden had experience of the issues around basement developments and their impacts, and some boroughs were now considering the use of Article 4 direction in order to limit permitted development in respect of basement excavation. Ms Waldman urged Haringey to consider the adoption of such an Article 4 direction. With regard to safeguarding measures, Ms Waldman expressed concern as to how the Council would ensure such measures were maintained and certified. The Committee was reminded that, once planning permission was granted, it could not be rescinded and so it was essential to get this right. Ms Waldman suggested that, where conditions were applied to a planning permission, neighbouring properties should be provided with a copy of the BIA and any relevant technical documents for their information.

In response to questions from the Committee, Ms Waldman reported that the Article 4 direction she proposed was to limit permitted development in respect of basement excavations, which currently allowed excavation below the footprint of an existing property and up to 3-4m beyond the footprint without the need for any hydrological assessment. Mr Dorfman advised that the position of officers was that this was nationally-agreed permitted development and there was insufficient evidence to warrant the introduction of an Article 4 direction, although if evidence were to emerge officers would look into this further. With regards to sustainable drainage, Mr Dorfman advised that Government were looking into strengthening the regulatory regime and making SuDS compulsory. It was reported that other boroughs were considering the possibility of an Article 4 direction in relation to basements, but none had implemented this as yet.

The Committee asked about flood risk in Haringey, and it was reported that the highest risk was in the upper lee valley, in the east of the borough; analysis of flood risk in the borough was currently taking place, and Mr Dorfman confirmed that if any increased risk was identified as a result of this work, the guidance would be adjusted accordingly and there may also be a change in policy. It was reported that, as a result of the concerns raised, the consultants working on the flood risk and Water Management Plan had been asked to look specifically at the issue of basements as part of their research. The Committee asked whether it would be beneficial to ask for BIAs at the validation stage for type 3 applications, in response to which Mr Dorfman advised that the approach needed to be appropriate and risk-based; currently there was no evidence of significant risk associated with permitted development in respect of basements and concerns could be addressed by means of planning conditions, but if such evidence were to emerge, policy would be altered accordingly. It was noted that there had to be an appropriate balance between the need to support developments coming forward and the valid concerns regarding the impact of development.

Professor Wright addressed the Committee on the impact that basement development at a neighbouring property had had on his home; this had led to subsidence and soil erosion, and had caused significant damage to his property as a result. The changes to the ground water had led to water bubbling up in front of his house. Professor Wright advised that basement developments were not a problem in and of themselves, but that the impact on neighbours needed to be fully understood. Photographs of the damage caused to Professor Wright’s property were circulated to the Committee.

In response to questions from the Committee, Professor Wright reported that the basement development in question had been 1-storey, but with a swimming pool then dug into the basement. It was confirmed that such a development, under this proposed guidance, would be classified as type 4 and would therefore require a BIA at validation stage, as well as relevant conditions. Professor Wright hoped that the proposed guidance note would help to ensure that such problems did not happen in the future.

The Committee noted that the guidance was intended as interim and would be reviewed and amended if circumstances were to change. Mr Dorfman confirmed that, as more information on this topic was gathered, this would be reported back to the Regulatory Committee and Planning Sub Committee as appropriate.

RESOLVED

That the draft guidance be noted as an interim measure for use by applicants and planning officers in determining planning applications for basement development in the borough.