Going Underground

There are few areas of planning law that can enliven the celebrities and moguls of London in the same way as that of basement development. It is a polarising topic and people are passionate in their views. Queen guitarist Brian May has even gone so far as to describe on his blog his basement-digging neighbours as 'selfish and brutish', referring to the piling rig they were using as an instrument of torture.

There is no denying that basement development has significantly increased in recent years. Karen Buck (MP for Westminster North) introduced the Basement Excavation (Restriction of Permitted Development) Bill 2015-16, a Private Member's Bill, towards the end of last year. At the first reading of the Bill on 16 September 2015, Karen Buck MP said: 'The impact of the size and scale of basement excavations on immediate neighbours is hard to overstate'. The Royal Borough of Kensington and Chelsea (RBKC) saw applications rise from 46 in 2001 to 450 in 2013; a 500% increase on 2003 figures. (The Bill has been withdrawn.) Why the recent surge in basement development? Despite popular press suggesting that the increase is due to greedy 'high-net-worth' individuals seeking to enhance their mansion homes with 'private leisure facilities' (swimming pools, tennis courts, garages and/or gymnasiums), in the main, the increase is owing to the rise in house prices.

For those in central London boroughs where space is at a premium and where heritage designations limit the potential for rear or roof extensions, 'subterranean development' (ie new basements and basement conversions) is often seen as a more economical means of increasing space than moving home. Many, particularly those who benefit financially from the construction of basements, suggest it is just a matter of smart maths. In London boroughs where the purchase price is at least £1,000 per sq ft, increasing space through a basement construction at approximately £400-£500 per sq ft is a far more affordable alternative, particularly when you consider the saved costs of not having to move (mortgage, agency and conveyancing fees, stamp duty, etc).

Unfortunately, one person's saving is often achieved at the expense of their neighbours.

Why is there so much resistance to basement development?

Basement development is typically opposed by residents due to the impact this type of development has on quality of life, namely construction noise and disturbance (which may continue for up to three years in extreme cases), but also due to fears over potential physical damage to neighbouring properties. While the majority of planning objections do not relate to the development outcome itself - most completed basements cannot be seen from the outside - there have been some extravagant 'iceberg' proposals that have enraged neighbours and Londoners in general, including:

the application by Tory donor Edmund Lazarus for a 16,000 sq ft mega-basement that proposed a 25m swimming pool, a cinema, a games room, a cigar room, a two-level gym, a catering kitchen and a yoga studio. Permission was refused; the application by John Hunt, the founder of Foxtons estate agents, to carry out work at his Grade II-listed mansion at Kensington Palace Gardens to add five underground levels to the existing three-storey home to create a giant 'museum' for his classic car collection, a swimming pool and full-size tennis court. The sub-fourth and fifth-floor basements were removed from the proposal, but an extension depth of 11m was ultimately approved in 2008 (see Government of the Republic of France v Royal Borough of Kensington and Chelsea [2015] at para 13); and the application by Turner Prize winner Damien Hirst to build a basement at his Grade I-listed home (14 bedrooms over five storeys) to house his...