*A selection of buildings that could be converted to homes using permitted development.*

Permitted development is “a national grant of planning permission which allow certain building works and changes of use to be carried out without having to make a planning application.” In a previous article, we discussed Part 1 of the general permitted development order, which sets out how households can use permitted development for home alterations. Here we discuss Part 3 of the order, which details permitted changes of use. Specifically, we will discuss how permitted development can be used to create new homes through change of use.

The Town and Country Planning (Use Classes) Order 1987 (as amended) categorises different types of property and land into classes. Change between use classes requires planning permission unless the change is included in the The Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended). I’ll refer to this as GPDO 2015. The following buildings can be changed into dwellings without the need for planning permission[1]:

Class MA commercial, business and service uses to dwellinghouses
Class N specified Sui generics uses to dwellinghouses
Class Q agricultural buildings to dwellinghouses

Creating new homes using permitted development has had a lot of bad press. When GPDO 2015 first came into force, it was the first time at that any conversions to a residential use were permitted. What resulted was a swathe of inappropriately converted buildings offering substandard living accommodation as unscrupulous developers capitalised on new opportunities to maximise profit.

Reports circulated of flats built with no windows, issues with noise and air pollution where flats were co-located with industrial units, and flats as small as 10 square meters - smaller than the recommended size for a double bedroom.

Terminus house is a particularly notorious example, having been the focus of a BBC Panorama investigation back in February 2020. They found families living in one room flats, with children’s beds located only a few feet away from the oven and kitchen sink. Despite being highly surveilled, by over 100 high-definition security cameras, crime in and around the building soared with 500 incidents reported within the first 10 months of the building opening. In 2023, a fire in the bin store beneath the building left corridors and stairs filled with smoke and residents struggling to find suitable escape routes.

Thankfully, the government accepted change was needed and now all dwelling houses created using permitted development rights must comply with the nationally described space standards and there must be a window in every habitable room. Converting storage or distribution centres and light industrial buildings to dwelling houses is no longer permitted, staving off some of the most inappropriately located developments.

What’s Permitted?

There are now three classes that allow for the conversion of non-residential buildings into dwellinghouses:

· Class MA commercial, business and service uses to dwellinghouses

· Class N specified Sui generics uses to dwellinghouses

· Class Q agricultural buildings to dwellinghouses

Each class has specific exclusions and conditions. In all instances, development is not permitted if:

The land is within an area of outstanding natural beauty
The land is within an area specified by the Secretary of State for the purposes of section 41(3) of the Wildlife and Countryside Act 1981 (enhancement and protection of the natural beauty and amenity of the countryside)(1);
The land is within a national park
The land is within a world heritage site
The building is in a site of specific scientific interest
The building is in a safety hazard area
The building is in a military explosive storage area
The building is a listed building
The building is a scheduled monument

Other exclusions only apply to some of the classes. These are summarised in the table below.

In all cases you will need apply for prior approval before beginning your project, but again the precise matters requiring prior approval differ for each class. Matters requiring prior approval and some additional conditions are set out in the table below.

There are precise procedures that must be followed when applying to the local planning authority for prior approval. These are set out in Schedule 3, Paragraph W of the GPDO 2015.

Achieving Quality

So, now you know what is permitted and you have heard about some of the worst examples, how do you go about creating quality homes using permitted development? As with any refurbishment project, to a certain extent the existing building will constrain your design. In the case of conversions, this is exacerbated as you will be using the building in a way it was never designed to be used.

Before embarking on a permitted development conversion, assess whether any of the constraints associated with the property are insurmountable. Things to look out for include:

Where the building is located.
A property that sits in an existing residential or mixed use area is likely to provide a better opportunity to create a decent home. Conversely, a building located in an out-of-town business park may prove a less than ideal environment in which to create a home.
The buildings’s form
Buildings with particularly deep plans will be more difficult to adapt in a way that achieves sufficient daylight to the interior spaces.

Assuming you are creating a single family dwelling, once you are satisfied that the property is suitable to be converted there are three primary factors to consider to ensure you are creating a home that facilitates well-being: space, daylight and air quality.

As discussed previously all new homes created using permitted development must now comply with nationally described space standards (NDSS). Compare the size of your building with the sizes given to determine approximately how many people could be suitably accommodated within your building. The diagrams below show how typical rooms might be configured in order to comply with the standards.

While calculating internal daylight levels is complex, there are some rules of thumb you can apply to get started. Consider placing non-habitable rooms such as bathrooms, storage and corridors, in the areas of the building that receive the least daylight. The depth of rooms is important. Rooms that have higher ceilings and/or windows on more than one side can be deeper and still achieve adequate daylight. Rooms towards the bottom of the building will generally need larger windows than rooms at the top in order to achieve the same levels of daylight. And finally, be mindful of orientations. Excessive glazing on the north face of the building can lead to cold interiors, while excessive glazing elsewhere can lead to overheating.

*Diagram illustrating some rules of thumb to consider when designing for daylight.*

The location of the property you are converting may mean that opening windows would lead to issues with the internal air quality, for example if the building is located on a particularly busy road or next to restaurants with kitchen extraction. In such instances you may need to consider mechanical ventilation systems to ensure a healthy internal environment can be maintained.

Take Away

Using permitted development to create new homes has received a substantial amount of bad press and in many instances, this was justified. Thankfully, the worst examples of homes created using permitted development can no longer be replicated due to changes to the GPDO 2015. While I am not advocating the use of permitted development to create the slums of tomorrow, done well it may provide you with a more affordable opportunity to create a home for yourself than purchasing property already in residential use. In this economic climate, who can argue with that?

[1] Class P (storage or distribution centre to dwellinghouses) and Class PA (premises in light industrial use to dwellinghouses) only apply to schemes that received prior approval before 10/06/19 and 01/10/20 respectively and so are not covered in this article.