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PERMITTED DEVELOPMENT RIGHTS

DOMESTIC
 

EXTENDING YOUR HOUSE (Link for Flats & Maisonettes)

You will need to apply for planning permission if you can say YES to any of the following:- 

  1. Your extension will be nearer to a highway than the nearest part of the "original house", unless there would still be 20m clear space between the house (as extended) and the "highway".

"ORIGINAL HOUSE" means the house as originally built, or as it was on the 1st July 1948. Previous owners may have already altered the house.

"HIGHWAY" includes all public roads, footpaths, bridleways and byways.

  1. More than half the area of land around the 'original house' (50%) would be covered by additions or other buildings.
  2. The extension will be higher than the highest part of the roof to the 'original house'.
  3. The extension will be more than 4 metres in height (measured from the highest ground level position beside the extension) AND within 2 metres of the property boundary. [ See Note below]
  4. The volume of the 'original house' will be increased by :-
  • More than 10% or 50 cubic metres (whichever is greater) for :-

- ANY TERRACED HOUSE (including end terrace), or

- ANY HOUSE within a National Park, Conservation Area, Area of Outstanding Natural Beauty (AONB), or the Broads (in Norfolk & Suffolk).

  • More than 15% or 70 cubic metres (whichever is greater) for any other kind of house located outside those particular areas.
  • More than 115 cubic metres in any circumstances.

6. The property is a Listed Building or in a Conservation Area.

CHECKLIST

 Required distance from the public highway.

 Still less than 50% of the land around the house is built upon.

 No higher than the original house.

 Within the 10%/50m³ or 15%/ 70m³ volume calculations.

 Not a Listed Building or in a Conservation Area.

BUILDING REGULATION CONSENT MAY BE NECESSARY EVEN IF PLANNING PERMISSION IS NOT.

 

 

 VOLUME is calculated by using external measurements for the proposed extension.

Volume calculations may also include the volume of other buildings (such as garages or sheds) if they are within 5 metres of the proposed extension and belong to the house. They may have been built at the same time as the house. So for example a detached garage near the house may be included, but one built at the end of the garden may not. [But see also below]

Similarly, the volume calculations must take account of any building which has been added to the property, that is more than 10 cubic metres in volume and which is within 5 metres of the house.

In any National Park, Conservation Area, AONB or the Broads, any building however far from the house which is of more than 10 cubic metres counts against the allowance.

Loft conversions and roof conversions which add additional volume will also count against the total volume of the house.

NOTE 1: I am indebted to Ms Angela Heeley of Heeleys Architects in Telford for correspondence on the matter of what may and may not be included in the PD Allowance for a dwellinghouse according to the ODPM, which I hope clarifies this matter a little more.

The following extract is contained in a letter from the Planning Policy Advisor to the Office of the Deputy Prime Minister, is provided for guidance only and is not a definitive interpretation of the law:

15th October 2002

Dear Ms Healey,
Thank you for your telephone enquiry yesterday about whether a detached garage should be deducted from the overall permitted development allowance for a dwellinghouse. This is an area where some differences of interpretation have arisen in the past. This Office cannot comment or rule on the facts of individual planning cases, because of the role of our Secretary of State in the planning system; nor can we provide a definitive interpretation of the law, as this is ultimately a matter for the Courts. However, I hope the following general remarks are helpful.

This Office considers that if a detached garage were built at the same time as, and within 5 metres of, the house, it would not be taken into account when calculating cubic content for future permitted development of the house involving enlargement, improvements or other alterations. However if, as a result of the development permitted under the "Town and Country Planning (General Permitted Development) Order 1995" (the GPDO), a detached garage - even one which was put up when the house was built or was there on 1st July 1948 - were to come within five metres of another building or proposed building in the curtilage, it probably would be regarded as if it were an earlier extension, so its volume would have to be deducted from the entitlement to expand the house taken into account when calculating cubic capacity limits. The GPDO is available to purchase from the Stationary Office Tel: 0870-600 5522.

Note 2: A case recently reported in “Planning” Magazine 5th November 2004 is also relevant:-

An Inspector has refused to issue a lawful development certificate for a loft conversion in north-west London on the basis that the volume of a former garage built within 5m of the house at the same time as the original house should not be counted in assessing permitted development rights.

The appellants argued that the cubic capacity of the garage should be included in calculating the total volume of the original dwellinghouse. On that basis the combined volume of the dormer and other previous extensions to the property would fall within the 15% limit set by Class B, Part 1, schedule 2 of the General Permitted Development Order 1995.

But the Inspector ruled that it would be inappropriate to include the garage in assessing permitted development limits. The capacity of the original dwellinghouse without the garage was 620 m³, giving permitted development rights of 93m³, he calculated. Since the volume of the existing extensions already breached this figure, he reasoned, the 10m³ dormer could not be permitted development.

Note 3: The following was noted in "Planning" magazine dated 11th February 2005. 


"The interpretation given is not the only one that can be made of this ambiguously worded part of the order.  Condition A. 3(b), which requires that existing buildings in the curtilage be included within a calculation of the resulting building where are they would be brought within 5m of a proposed development under class A, is not repeated under class B.  The PM's advice is directly contradicted by the commentary on the order in the Encyclopaedia of Planning Law and previous advice in Planning magazine 2 July 2004. Such inconsistencies in interpreting the legislation are all too frequent and can only serve to undermine the reputation of planners, since they create the unfortunate impression that they do not understand their own area of purported expertise.  I would be interested to know whether this particular anomaly is to be removed as a result of the review of the order.

 

My advice reflected more recent appeal decisions where condition A 3(b) has been discussed in the context of a lawful development certificates for dormer extensions.  In these cases it has been held that the limitations on class A become relevant in assessing whether the cubic content of the "resulting building" would be exceeded by the tolerances set out in class B.1(d).

 

Paragraph 1of part 1 defines "resulting building" as meaning "the dwellinghouse as any large, improved or altered, taking into account any enlargement, improvement or alterations of the dwelling house, whether permitted by this part or not".  The view has been taken that have the effect of paragraph 1 is to set a single, cumulative limit under any class in part 1 that results in an enlargement. 

 

While class A has no direct bearing on a dormer extension, the definition of the resulting building in paragraph 1 means that any enlargement under class A must be taken into account in assessing whether the tolerances under class B.1(d) would be exceeded by a proposal.  The difficulties in applying condition A.3(b) were highlighted in the review of permitted development rights commissioned by the ODPM in 2003.  However the report's recommendations were not mentioned in the recently announced review of householder development consents.

All credit to the Planning magazine experts for trying to shed more light on this tricky issue but even so the matter remains open to interpretation and a definitive answer may remain illusive for some time to come. IPB

 

 

 

 

NOTE: This part of the permitted development rights has caused confusion. Development is usually allowed up to the property boundary. The 2m limit only applies if that development will exceed 4m in height. This restriction does not apply to roof extensions.

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