If space is tight in your property and the current economic situation makes a move inadvisable, then converting an existing outbuilding into self-contained accommodation can be a good way to get the extra space you need.
It can be used as an annexe for an elderly relative, a teenage bolt-hole, guest accommodation or even rented out to provide supplementary income. You can build something in the garden if you don’t have any existing outbuildings.
Planning permission will almost certainly be required when extending your accommodation in this way as well as building regulatory approval. In England and Wales new rules were introduced in October 2008 to relax planning laws and structures built in the garden are now considered 'permitted development' and therefore do not need planning permission.
However, accommodation is expressly excluded from this rule. So rather than looking for ways to get around this it's easier to bite the bullet and start by discussing your plans with the local planning office.
Serious Plumbing For Accommodation In Outbuildings
The major functional difference between self contained accommodation and something like a home office or studio is that you will need to put a proper bathroom or shower room in with a toilet. This means connecting to a water supply, having a way of heating water, and connecting to the sewer system. It makes the job more complex as you would be unlikely to put all that into a separate extension that would only be used occasionally.
Unless you have done a lot of other plumbing jobs this is best left to an expert. Connecting to a sewage system is not something that you want to have problems with. Nor do you want anything to go wrong with the water supply to your main property if you get that connection wrong too.
As far as hot water goes you could install a gas fired instant boiler if the gas main is near enough to the property, otherwise the cheapest to install would be a hot water cylinder and an electric heating element. It might not be the cheapest to run though.
Insulating And Damp-Proofing A Separate Building
Other areas that might differ with accommodation rather than extending for occasional use are the insulation, damp-proofing and heating. The more you insulate an outbuilding the easier and cheaper it will be to heat, so if it is a single skinned building it would be wise to add a layer of internal insulation then plasterboard cladding.
A damp proof course is advisable although how much and how it is installed depends on the construction of the building. If you are extending by building a standalone timber building then a concrete base with a damp proof membrane incorporated into it is probably the easiest option. Wooden buildings can also be made reasonably damp proof by raising them off the ground slightly on blocks, perhaps with a slate in-between as well.
Heating For Self-Contained Accommodation
As far as heating goes, the better the insulation the less it will have to be heated. With a single room extension such as a home office or studio you can probably get away with a single electric radiator or portable propane gas heater, but self contained accommodation is likely to have more than one room and as such will probably need a network of radiators.
These could be electric but they do tend to be more expensive to run than a gas central hearting system. If gas is available and you're putting a boiler in for hot water anyway then it makes sense to extend the system to cover a few radiators. To be honest it depends how much you want to spend and how warm you need the place to be.
We're travelling campers, staying in Spain, Portugal and Holland throughout the year.
We have a house (currently rented) which we'd like to build an outbuilding at the bottom of the garden, for personal storage and a place to occasional rest from travelling.
I understand I can build without planning permission, but the condition :
6. To be permitted development, any new building must not itself be separate, self-contained, living accommodation and must not have a microwave antenna.
Says I can't occasionally sleep overnight in that building.
Am I correct?
Should I then make planning application for this outbuilding with occasional residential use indicated?
Many friends say, "don't bother with PP" but we are nervous about the outcome should we be discovered.
Stuboy_spain - 26-Sep-20 @ 3:14 PM
I'm wanting to construct a log cabin in my parents garden it under 30m2 in size no more than 2m high.. but needs a bedroom my parents gave permission to use there services gas/electric/water etc but do I still need planning permission for the project.
Dave - 6-Aug-20 @ 10:28 AM
I built a brick built garden office/gym 5 years ago with planning permission. It is just under 30 square metres just under 4 metres high and 2 metres away from the boundary. The footings are 900mm deep and it is double skinned and insulated.There is drainage, water (shower and toilet) and power already connected. I built the footing as there are very established beach and oak trees around 5 to 10metres from the building but there is no signs of any shrinkage/subsidence. Is it possible to change it's use to a self contained dwelling for my son
J m - 13-May-20 @ 7:26 PM
Need a self contained outbuilding back of garden
Ibby - 24-Dec-19 @ 2:37 AM
I am planning on building an outbuilding 9.6 x 5.5m where I have already been granted 9.6 x 4m with planning application.i now realised I need a bigger place as I’m putting in cavity walls. I have on the plans a bathroom, used for storage and gym and office. Because of the size issue I don’t want to go down the planning application route again since I’ve already wasted a lot of money just designing this. With the new size it’s still less than 50% of the garden space. Will I still be allowed to have a bathroom as I was going to have one anyway and my planning was granted. Rather than submit a new plans for new size I was thinking of going via the route of PD. Will there be any issues I should know of? It’s basically increasing the size by 1.5m bigger as I didn’t account for the cavity wall sizes and it just feels smallish.
Faz - 8-Apr-19 @ 4:53 PM
Please see previous message to contact myself reference conversion of existing outside building to office / studio space
Regards Edwin Herrnicht
Area - Banstead Surrey
Ed - 13-Jun-18 @ 8:41 PM
Eva - Your Question:
Hi,i wanted to build a bedroom ensuite in the rear of my semi detached property.however in the reading council website - Outbuildings section it stated that "To be permitted development, any new building must not itself be separate, self-contained, living accommodation and must not have a microwave antenna."Does this mean I cannot have bedroom with bathroom in outbuilding?RegardsEva
Yes. You may be able to do this but you would need to apply for planning permission (i.e it doesn't fall into "permitted development")
ExtensionBuild - 5-Jul-17 @ 11:26 AM
i wanted to build a bedroom ensuite in the rear of my semi detached property.
however in the reading council website - Outbuildings section it stated that "To be permitted development, any new building must not itself be separate, self-contained, living accommodation and must not have a microwave antenna."
Does this mean i cannot have bedroom with bathroom in outbuilding?
Eva - 4-Jul-17 @ 12:05 PM
Marie Edgar - Your Question:
I have an outbuilding currently used as a store room and want to convert it to a shower room and mini kitchen. It needs a new roof so something has to be done to it to prevent deterioration.It has a flat roof and single layer of brick walls. It joins with a playroom which is brick built and could be used as a bed sitting room with a door to the new shower room and kitchen.I would like to use it for Air BnBHow do I start?
You don't usually need planning permission to convert an out building but you may do if you intend to rent it out for more than a set number of days per year. In London, additional planning rules apply in relation to airbnb. You will also need to comply with building regulations. The simplest way to find out how to go about it is to contact your planning & building control office.
ExtensionBuild - 27-Jun-17 @ 12:51 PM
I have an outbuilding currently used as a store room and want to convert it to a shower room and mini kitchen. It needs a new roof so something has to be done to it to prevent deterioration.
It has a flat roof and single layer of brick walls. It joins with a playroom which is brick built and could be used as a bed sitting room with a door to the new shower room and kitchen.
I would like to use it for Air BnB
How do I start?
Marie Edgar - 25-Jun-17 @ 3:05 PM
I am hoping to convert a coal shed into a living space and was wondering if this is likely to be expensive?
It has a flat roof - would this need to be changed?