Office ext generic

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But the decision by Philip Hammond to allow upwards extensions through permitted development rights (PDR) is significant news. This is set to go ahead via regulations due this autumn and follows an extremely contentious consultation earlier this year.

In the absence of a planning process to scrutinise projects that will add to building heights, the issue of rights of light (ROL) becomes a very serious consideration, and one with significant consequences.

Because daylight and sunlight assessments are usually a component of a planning application, they are needed at an early stage in the process. Until now, local residents with legitimate concerns have also been able to comment.

So while developers might look set to gain from the opportunity to create additional storeys, in reality the situation is precarious. Without the stringent procedures and ultimately the reassurance that the planning system offers, developers could potentially embark on building works and only on completion suffer significant consequences. This could be anything up to a year after development and in extreme cases up to six years.

The likely result of this change in policy is an increase in the number of both investigations and claims. Although we anticipate that the PDR will consider issues including overlooking and overshadowing, it is unclear how this would be implemented.

Strategically minded developers may seek to prevent or extinguish ROL from being acquired by issuing a light obstruction notice for a period of 12 months prior to construction – after which a claim for light is nullified if left unchallenged, thereby resetting the prescriptive 20-year clock.

While PDR offer some freedom, too much freedom can be dangerous. Pushing risk further down the line only increases risk. So developers are advised to seek professional advice at an early stage to avoid the significant expense of having to pull down an extension and begin again.

Daniel Wade, rights of light director, Trident Building Consultancy