Combined Residents' Associations of South Hampstead



Basements have become increasingly popular in areas such as ours where rising property prices have made the cost of moving home so expensive.  Many residents prefer not to lose garden space to extensions and as the technology for basement excavation advances, and the cost of a home in South Hampstead reaches a reported £1,100 per square foot, it seems inevitable that we will have to brace ourselves for more in the future. There is no doubt that basement developments cause great distress, as any resident unfortunate enough to have had to live through neighbouring building works will tell you. CRASH's recent Neighbourhood Basement Survey disclosed numerous reports of damage as a direct result of neighbouring excavations and almost all respondants stated that they would like to see them halted.


We have at least 41 basements in the 15 streets which make up the CRASH area and there are at least three more another applications being considered in Camden.  One of the latest, in Canfield Gardens will be the sixth in a row of nine adjacent houses which now have basements and the10th among the street's 51 semi-detached houses.


The Neighbourhood Survey invited 100 residents living close to recent or ongoing basement excavations to respond to questions on their attitude to, and experience of, nearby developments.  We received 37 responses.  Of those, 34 stated that they would be "very likely" to oppose an application to excavate a basement in a house nearby.  21 people said that, on average, such building works lasted 18 months or longer.  20 people said they thought that, where work had been carried out, the impact on the appearance of the property or garden had been for the worse and 30 respondents told of changes to their property during neighbouring construction work ranging from minor cracking to serious flooding.  There were 29 reports of similar further destabilisation and damage following completion of construction, as well as numerous stated problems with noise, vibration, dust and traffic chaos while those works were in progress.  In August 2013, CRASH wrote to Francis Wheat, Camden's Head of Development Management, to draw attention to some of the consequences of current policy on basement development which we believe had not, up until that point, been considered by Council.  Not the least of these is the fact that insurance premiums for houses within a radius of as much as 400 metres of a basement excavation are now being penalised with increased insurance premiums and, in some cases, being refused insurance cover altogether. Stride Insurance Goup now insist on a Property Subsidence Questionnaire being filled out by everyone applying for household insureance. Despite this, Camden, like every other Borough Council, accepts no responsibility for the insurance difficulties caused by their continuing to approve neighbhourhood basements


These difficulties affect not only the people living near houses which have been excavated but the very home-owners who are doing the digging out.  A recent survey by the brokers Insurance Tailors revealed that only 5% of people who carried out structural work, including digging out basements, had informed their insurance company of those works.  This meant that, for most, their home insurance cover would have become invalidated the minute they started work, so that neither they nor their neighbours would have been protected against any structural damage caused.  Residents are advised to check that the neighbours digging the basement have obtained adequate and appropriate insurance cover - from taking out specialist insurance policies to setting up special contingency funds in case of damage.  It is vital that a party wall award - a legal agreement between neighbours - is in place before any work begins.  This aims, among other things, to mitigate the levels of disturbance and includes a legal assurance that any damage caused to the neighbouring property will be recitified within a specified period. Despite this, however, CRASH has heard of too many cases where a developer or their insurers disputes that damage has been caused by the basement works.  And If you are trying to sell your home while basement works are going on nearby, be prepared for a fall in the value!  


Camden's existing Planning Guidance CPG4 (Camden Planning & Guidance 4 - Basements and Lightwells), based on Arup’s recommendations, goes some way towards ensuring protection for neighbours and the environment, requiring developers to prove by a professionally prepared Basement Impact Assessment (BIA) that neither will be harmed during building works.(See Camden Planning and Guidance 4 on Related Links on the Home page of this website)  Nonetheless planning applications which pay insufficient attention to this area’s underground water conditions or which give insufficient consideration to the possible destabilisation of neighbouring properties have continued to be submitted and, frustratingly, have often been approved by Councillors and Planning Officers who were insufficiently briefed in the challenging detail of the policies of CPG4, as well as the necessary technical and hydrological expertise required to evaluate the risks of such developments. Camden carried out a consultation and review of the planning requirements of CPG4 and, since September 2013, an amendment to the regulations requires independent verification, funded by the applicant, of any BIA where, 1)  A scheme requires applicants to proceed beyond the Screening stage (i.e. where a matter of concern has been identified.  2)  Where the proposed basement development is located within an area of concern regarding slope stability, surface water or groundwater flow.  3) For any other basement applications where the Council feels that independent verification would be appropriate (e.g. where conflicting evidence is provided in response to a proposal.  The Council is currently in the process of appointing a single organisation to independently assess BIA's and they state that this approach will ensure that the appointed organisation benefits from a thorough knowledge of the Councils policies and approach to arguments and will develop an understanding of the history of basement applications and their potential cumulative impact.


Our continuing concerns over the proliferation of basement development in South Hampstead persuaded CRASH to help initiate the setting up of CRAAC (Camden Residents Associations Action Committee) an organisation of 25 borough-wide associations committed to persuading Council to amend current basement planning policy in order to mitigate many of the issues of concern about such developments across Camden. Sadly the planning system in the UK is generally a reactive system weighed disproportionately in favour of the developer.  Even on occasions when an independent review of an application is called for (and CRASH has been pressing Camden to insist on such a review for every basement proposal) it invariably results only in an inventory of any outstanding issues of concern being presented by the reviewer, no matter how critical those concerns might be. Nowadays Camden seems routinely to recommend approval with an attached Section 106. This, in effect, allows building works to commence before contentious issues have been resolved to all parties’ satisfaction, with Council happy to rely only on an assurance from the developer that causes of concern will be addressed as the work progresses. Residents have little or no means of consultation and few of their worries are properly addressed or taken into account. Too often this results in a neighbour having to spend large sums of money acquiring specialist advice from lawyers and/or structural engineers to safeguard themselves against developers’ inadequate planning detail, deficient basement impact assessment or the decision of a planning officer who is frequently insufficiently briefed in the challenging detail of Camden’s policies DP27 and CPG4. CRAAC wants to see developers ensure some financial guarantee is in place before work begins so as to safeguard neighbours against damage to their properties.


So far we have had two meetings with the Council to discuss these matters and there is are more due. Nonetheless progress is slow. Camden continues to believe that a sound Party Wall Agreement is all that is required to sort out any problems caused by basement excavation although it is clear that a Party Wall Agreement, of itself, is no longer fit for purpose when it comes to dealing with the structural and ecological problems that are often  involved.  Originally designed to settle claims for damage done to neighbours’ properties above ground, where there was less doubt as to the nature of, and who was responsible for, any damage, the Party Wall Agreement is now being interpreted in a way that was never intended, allowing many less scrupulous developers to do any amount of damage to a neighbouring property so long as it is repairable.  And all too often, if the cases which have been brought to CRASH’s attention are anything to go by, the Party Wall Agreement has even then not prevented expensive court-room battles to get compensation for any repairs, even when they are clearly a direct result of the developer’s works. CRAAC, under the excellent chairmanship of Oliver Froment, continues to press its case.  That campaign is not helped, however, when, as happened recently in Aberdare Gardens, an application for a 5-metre deep basement and swimming pool, refused by Camden, was overturned by the Planning Inspectorate when the developer went to appeal.  After a decision, such as this, goes against them, Camden has to pick up the bill for the entire appeal procedure, as well as, in this particular case, the army of legal and structural experts drafted in by the developer to support his case. Understandably, Council is often reluctant to turn down subsequent basement applications if a refusal is likely to involve them in yet another such appeal and further such expense.


There is still much Camden could do to obviate such outcomes. By simply enforcing their own stated legal limit to the depth and expanse of any basement development in Camden, as is now being enforced by some other London Councils, the Planning Inspectorate would have no option but to assess an appeal in light of these stated limits and uphold Council’s refusal  against appellants whose proposed developments exceed them. As there is presently no stated legal limit within Camden, the Planning Inspectorate had no justifiable reason not to allow the basement development in Aberdare Gardens. The Basement debacle is causing problems across London and looks set to rumble on for a while yet.  Do keep us up to date with any issues of concern in your immediate vicinity.  We would also be interested to hear any case histories of problems you might have experienced as a result of a neighbour’s excavations. We will be sure to keep the information you provide confidential but details would provide us with further evidence for our ongoing conversations with Council and, hopefully, add strength to our argument.  It is vital that residents keep abreast of all planning applications - most especially if they involve basement excavations - and join with other neighbours to object whenever there are valid concerns over the consequences and effects of the planned building works. And, most important of all, report your concerns to CRASH.   More than three objections from neighbours affected by the intended works will ensure that the case is reported to Camden's Members Briefing Panel, even when an assigned planning officer is minded to recommend approval. That panel can then request that the application be reported to the Development Control Committee, (something CRASH would like to see as standard for every basement application) at which residents can voice their objections and hear Planning Officers and Councillors debate and consider the merits or otherwise of the application.  


If you have doubts or concerns of any kind about a neighbourhood plan for a basement contact CRASH immediately.