Plannning Application for property  sub divisio of an ar galery into anew restaurant and twobedroom flat in King's Lynn, Norfolk. En-Plan: Property sub division planning cosultants.



Planning Consultancy:


Property sub-division and the Planning System

This interesting field of planning and development will allow you to create new planning units within existing buildings and thereby increase either rental yield or overall value of the building by producing more units. It might take different forms such as:

• Conversion of existing non-residential buildings and vacant properties into
• Subdivision of existing houses into maisonette and/or flats;
• Conversion of accommodation above shops into flats.

“Adequate space is a pre-requisite for basic living. There should be enough room for residents to cook, eat, relax and socialise. There should be sufficient space for furniture and the storage of personal possessions. If homes are to have a long life, they must offer functional and adaptable spaces that meet the needs of families, children, older people and disabled residents.” (CABE – Space in New Homes: What Residents Think - 2009)."

Conversion and sub-division of existing buildings can be a sustainable form of development as it gives a new lease of life to the existing buildings which might be redundant or economically unviable in their current use. It would reduce the waste and carbon emissions arising from the demolition of the old buildings, the embodied energy in the materials of a demolished building and the construction of new buildings.

With sympathetic alterations to the exterior of the existing buildings, conversion is likely to have a lower visual impact on the street scene by preserving the existing building frontage and respecting the character of the

However, unsatisfactory conversion work can result in accommodation which is of an inadequate size and poor quality. The occupants could be exposed to a number of potential problems, such as overlooking, poor outlook,
overcrowding and lack of amenity space, inadequate light, noise and disturbance from neighbouring premises, and inconvenient and unsafe access.


National Space Standards are in effect whereby the new dwellings formed by sub-division and conversion of existing buildings are required to provide satisfactory accommodation in terms of size and are broadly in line with the requirements of the English Partnerships Minimum
Space Standards,  the following minimum internal space standards should be
applied to new subdivided dwellings:
Number of bedrooms / persons Minimum internal space (m2)
1 bedroom homes 51sqm
2 bedroom homes 72sqm
3 bedroom homes 93sqm
4 bedroom homes 106sqm

Property sub-division and Building Regulations can be a complex area and if you are carrying out building work personally, it is very important that you understand how the building regulatory system and material applies to your situation as you are responsible for making sure that the work complies with the building regulations.


If you are employing a builder, the responsibility will usually be theirs - but you should confirm this at the very beginning. You should also bear in mind that if you are the owner of the building, it is ultimately you who may be served with an enforcement notice if the work does not comply with the regulations.

Some kinds of building projects are exempt from the regulations, however generally if you are planning to carry out 'building work' as defined in regulation 3 of the building regulations, then it must comply with the building regulations. This means that the regulations will probably apply if you want to:

  • Put up a new building

  • Extend or alter an existing one

  • Provide services and/or fittings in a building such as washing and sanitary facilities, hot water cylinders, foul water and rainwater drainage, replacement windows, and fuel burning appliances of any type.

The works themselves must meet the relevant technical requirements in the building regulations and they must not make other fabric, services and fittings less compliant than they were before - or dangerous. For example, the provision of replacement double-glazing must not make compliance worse in relation to means of escape, air supply for combustion appliances and their flues and ventilation for health.

They may also apply to certain changes of use of an existing building. This is because the change of use may result in the building as a whole no longer complying with the requirements which will apply to its new type of use, and so having to be up-graded to meet additional requirements specified in the regulations for which building work may also be required.

In summary, the following types of project amount to 'building work':

  • The erection or extension of a building

  • The installation or extension of a service or fitting which is controlled under the regulations

  • An alteration project involving work which will temporarily or permanently affect the ongoing compliance of the building, service or fitting with the requirements relating to structure, fire, or access to and use of buildings

  • The insertion of insulation into a cavity wall

  • The underpinning of the foundations of a building

  • Work affecting the thermal elements, energy status or energy performance of a building.


Before commencing work you should refer to Regulation 3 of the Building Regulations for the full meaning of 'building work' or, if you are unsure, seek advice.


Once you have decieded that you do need building regulations approval you have a choice of where this can be obtained. Learn about different types of building regulations approval and where to get approval in our how to get approval section.

You will need to submit a full plans application showing in particular:

Means of escape and fire protection
Fire alarms and emergency lighting
Sound Proofing details and eventual testing
Structural calculations
SAP calculations

En-Plan have extensive experience in this field and can provide you with full working drawings for any property sub-division project and thereby allow you to get accurate quotations from Builders and give you the knowledge that you are working to an approved specification.  Please refer to our dedicated Building Regulations page for more information.

Contact us

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Shropshire Office


Back Lane

Bomere Heath



Norfolk Office

34 Queen Elizabeth Avenue

Kings Lynn


PE30 4BX

En-Plan: Planning & Architectue Chartered Planning Consultants Chartered Town Planning Consultants


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