Hello fellow members,

I’m designing a garden room but struggling to get the height under 2.5m to avoid planning permission. I submitted a pre-planning application and the council suggested it might be difficult to gain planning for a garden room over 2.5m because of the proximity of my neighbour’s house.

I’m currently looking into options for making it within 2.5m high. The size is 3.5m deep by 4m wide.

My current measurements look something like this:

180mm Roof
100mm lintel
2000mm door
18mm OSB subfloor
150mm joist with 100mm of insulation in
50mm Ground screw
0 ground level

Working from the ground up I’m left with 180mm for the roofing. That includes joists and a 70mm Firring strip to give the roof a 1:60 gradient. I originally wanted to construct a warm roof but think I would struggle with getting a well-insulated cold roof in under 2.5m.

From my research, it seems impossible to get roofing, joists and firring strips into 180mm while maintaining 90mm for insulation.

Does anyone have any suggestions of how I might be able to achieve the design coming at 2.5m?

I am currently researching using insulated roof panels that span 3.5m without using joists. There does seem to be a minimum gradient of 4d for a lot of these, and currently, the garden room is just over 1degrres.

Any suggestions or insights would be greatly appreciated.


Thanks,

2.5m is if the building is within 2m of the boundary, for it to be Permitted Development and not need planning permission.

Or apply for householder planning permission for the building in the position that you want and at the height that you can achieve.
If it ends up being e.g. 2.6m at the highest point then the Council has to assess whether that additional 100mm (over what you can do without planning permission) has such a negative impact on the neighbour that it justifies a refusal, and whether that refusal will stand up to appeal.

My experience is that a nearly-flat roof causes more problems than it solves, especially with a cold roof (they are no longer allowed in Scotland).

The planning exemptions mentioned, are really aimed at garden tool sheds and the like. For the substantial outbuilding you have in mind, it would be a pity to compromise on the headroom and durability over the whole lifetime of the building, just to avoid planning permission? Especially if that means using expensive thin insulation panels.

How about designing the building you really want, with decent headroom and a well insulated (deep) floor and roof, taking it through the planning process, and adjust to any objections that come up? Are your neighbours ok with the idea in principle?

Householder PP is £206 now, if you apply via the Planning Portal you also have to pay their admin fee of £28
although you can just email it to the Planning department of your Local Council.

Thank you for your replies,

Posted By: Dominic CooneyYou could move it more than 2m from the boundary but I'm guessing you don't have the space?

your correct, i don't have space. It's a narrow garden of 5 metres, the issue is with the property at the rear of the garden, the neighbours to the sides will be fine. the house to the rear sits about 4 feet lower than my garden.

Posted By: WillInAberdeenHow about designing the building you really want, with decent headroom and a well insulated (deep) floor and roof, taking it through the planning process, and adjusting to any objections that come up? Are your neighbours ok with the idea in principle?

Thanks for this. I will apply with my original design of a warm roof and the original height. I have attached a working design of what I have. I will keep it to 3m in height, this allows for a warm roof and a decent amount of head room.

Posted By: Dominic CooneyIt could cost that much with current material prices and inflation!

i know, probably not the ideal time to be planning such a build. But is there ever the right time.

Posted By: fostertom

Posted By: Dominic Cooneyif you apply via the Planning Portal you also have to pay their admin fee of £28
although you can just email it to the Planning department of your Local Council.

I've just found that possibility's been shut off - no email address now provided on website for Planning Dept, and no phone access to check! The only possibility is an automated phone line to book a session with the Duty Officer within a week, for non returnable payment of £25.

Which council is that? Putting a paper copy through their letterbox is still a possibility I suppose, if all else fails. Although I'd have thought you had their phone and email on file.

Hmm, it seems they've gone further than my local council. They still publish email and phone numbers but they do say to submit applications via the portal, or alternatively to fill out paper forms.

Posted By: jamesingramdig out and build with with floor level with ground , leave a gap around and retain and strut with sleepers or gravel board

Pretty much what I was thinking. Why not go down half a meter and solve the problem that way?

I would like to think that South Hams are obliged to accept planning applications by email. That’s got to be easier for them than paper applications with all that scanning in.
Plus there are some types of applications that you can’t submit on the planning portal.
Perhaps they are due a formal complaint asking why their planning email isn’t on the website.

Posted By: Dominic CooneyI would like to think that South Hams are obliged to accept planning applications by email. That’s got to be easier for them than paper applications with all that scanning in.

I don't think you're correct. Perhaps you could point to the relevant legislation if you think you are? I think it's more likely they are required to accept paper submissions. I doubt there's any legislation requiring them to accept anything by email.

Posted By: Dominic CooneyPlus there are some types of applications that you can’t submit on the planning portal.

So this would result in multiple paper copies being required to submit, which is a waste of paper, that then have to be scanned in and added to the electronic file. I even remember one LPA printing out applications submitted electronically, so that they could then scan them in and add them to the electronic file. Nuts.