Changes in Permitted Development you don't want to overlook.
Not many of us are aware that the Permitted Development rules have been extended over the last two years.
Although the general rules for domestic extensions and loft conversions remained unchanged, a couple of new Permitted Development classes have been introduced which is good news for all of you thinking about going up rather than extending out into the garden.
Only very limited information is given on the Planning Portal and sometimes even professionals are unfamiliar with the recent updates, therefore this guide aims to clarify and demystify common misconceptions on the subject. We hope it will come handy to all interested potential developers and promise to write in a plain language with no industry jargon or unnecessary information. Who knows maybe it will inspire you to explore new options that the legislation provides and improve your current house in the near future in a way that has not been possible before.
General rules for construction of additional storeys over existing house:
The new class AA (Part 1) of General Permitted Development Order (GPDO) 2022 allows to extend a dwelling house by up to two storeys for a 2 storey house and by 1 storey for a bungalow. The general rules are as below:
the most important information to remember is that you cannot start works without prior approval, therefore a permission has to be granted beforehand.
up to two additional storeys allowed where the existing house is a two or more storey building.
only one additional storey is allowed where the existing house is a bungalow.
Restrictions on the new Class AA (Part 1) of permitted development rules:
The following restrictions apply:
the existing house cannot be located in the conservation area
the existing house has to be purpose built as a dwelling and not converted before
only houses built between 1t July 1948 and 28th October 2018 would be illegible to benefit from this part of Permitted Development Order
if the property has been already extended upwards the additional storey will not be considered a permitted development
total height cannot exceed 18m
the highest part of the extension cannot exceed 7m for two storey existing house and 3.5m in case of a single storey existing house.
In case of a terraced building the height of the extension cannot exceed 3.5m over every other building in the row in which it is situated
the floor to ceiling in the proposed enlarged part cannot be higher than 3.5m or than any existing floor to ceiling height.
it has to be constructed on the principal part of a dwellinghouse
Design criteria for Class AA(Part1) Permitted Development:
The proposals also have to meet certain criteria which are as follows:
materials used to be similar to existing
no windows are allowed on flank elevations
existing roof pitch has to be replicated over the proposed additional storey
Things to consider:
-drawing from experience, the existing foundations are very often not able to sustain additional load from extra extension on top. We would recommend appointing a structural engineer to carry out a structural survey to confirm it and if so, the underpinning might be required.
- if the existing house has a flat roof only flat roof can be proposed for your extension and similarly for an existing house with pitched roof only a pitched roof can be proposed
- if your property is a terraced house in a row of houses of similar height, it is very likely the application might be refused based on being out of character and affecting neighbouring amenities.
Conclusions
Although all the above conditions may seem easy to comply with, the planning departments can and will still assess the impact on neighbouring amenity, overlooking, privacy and loss of light, which in our opinion is the major catch in the legislation. In this respect it would mean that the application is no different than a planning application in many cases.
But do not discourage as with a specialist’s advice it can be overcome. On one of our noteworthy projects, we even used this sort of application as a fallback to obtain a full planning permission for a bigger, and much more attractive two storey extension.
Atelier 41 Architects have submitted multiple successful applications using the above Class AA permitted development rules (also in Gren Belt area) which has allowed us to gain substantial knowledge and experience in this field.
Should you require any further or customised advise please do not hesitate to ask our team of experts on our web chat or over the telephone conversation. We are always happy to help.