Potential garden room/gym - early stage ideas

[Adsibob]

So I haven’t recovered from the stress of the first build, but already I’m getting the bug to build an outbuilding at the back of my garden to house a home gym, perhaps with a large overhanging roof to create a shaded patio area.

 

 Didn’t really get on with the planning system last time around, so toying with the idea of doing it under PD so that we can bypass the f🤬🤬kers . I suspect this won’t be workable. Here are the constraints:

 

 the garden is rectangular and about 8.6m wide. I understand I can build across the full width under PD as long as the maximum height of the building is 2.4m. That is my preference, since if I go higher than this, I need to be 2m from the boundary which cuts my building width from 8.6m to 4.6m.

 

 The depth of the building would need to be about 2.6m internally, so depending on wall thickness, this would equate to an external footprint of about 3.3m deep, by 8.6m wide, with a maximal height of 2.4m. Haven’t thought about roof design, but maybe tiled with a slight pitch. There won’t be any roof lights. 

 

 The other limitation is that at the rear of my garden, we have a row of about 6 Leyland cypress trees. These were about 11m tall when we bought the house 6 years ago, and grew at a rate of about 75cm a year until we lopped the top of them off about 2 years ago. They are now about 8m or 9m tall and we would prefer to keep them, given they provide excellent screening and privacy from the neighbours on the other side of our rear boundary. The row of trees is about a metre from the rear boundary fence. My preference would be to find a solution that enables us to build the outbuilding as close as possible to this row of trees, without damaging them. 
 

A further limitation is that I would like the outbuilding to be insulated so it stays cool in summer and can be used in winter without spending too much heating it. It will only be used a couple of hours a day, but still want it to be comfortable. Therefore, we will lose a chunk of the height in insulation materials, particularly if we are going to achieve a half decent decrement delay. So that we can still have a decent internal head height, I’m thinking of sinking the building into the ground, so that externally it is only 2.4m above ground level but internally, you take two or three steps down to reach a slightly subterranean floor. I appreciate this will add complexity and cost, given it might need to be tanked, but I think it will make the place much more enjoyable.

 

Any thoughts as to whether such a building and the existing leyland cypresses can co-exist or is this madness? The soil type is London clay.

 

 What construction type would you consider?

 

 

 

 

 

 

Edited August 4 by Adsibob

[garrymartin]

Don't forget building regulations...

In brief:

1) Building Regulations do not usually apply unless you want to sleep in it

2) Under 15m2 INTERNAL floor area can be installed close to any rear boundary

3) Over 15m2 and up to 30m2 needs to be a minimum 1m from any boundary

 

If you want to put up small detached buildings such as a garden shed, garden room or summerhouse in your garden, Building Regulations (except Part P for Electrical works) will not normally apply if the floor area of the building is less than 15 square metres INTERNALLY and contains NO sleeping accommodation. If the INTERNAL floor area of the building is between 15 square metres and 30 square metres, you will not normally be required to apply for building regulations approval, providing that the building contains NO sleeping accommodation, and is either at least one metre from any boundary, or it is constructed of substantially non-combustible materials.

 

I kept it to below 15m2 for mine. It's well insulated and works well as a room despite the 2.4m restriction, but as a gym, you'd probably need higher ceilings for anything that involves you putting your hands above your head, so as you note, you may have to dig down if you don't want to apply for planning permission.

[DevilDamo]

50 minutes ago, garrymartin said:

despite the 2.4m restrictio

It’s 2.5m and only when within 2m of a boundary.

 

People would have to be careful if they are start reducing levels in order to provide more height as you start getting into the realms of an engineering operation, which would require Planning.

[Russdl]

@Adsibob is your garden sloping?
 

If so you may be able to take advantage of that. The 2.5m restriction is measured from the highest part of ground adjacent to the proposed building which naturally makes the building higher with relation to the lowest ground if there is any slope. 
 

I hope that makes sense? Reads like gobbledygook to me 🤣

[Adsibob]

2 hours ago, Russdl said:

 

@Adsibob is your garden sloping?

 

Unfortunately not. At least not noticeably. Unlikely to be perfectly flat, but if it has a slope is negligible.

[Adsibob]

5 hours ago, DevilDamo said:

People would have to be careful if they are start reducing levels in order to provide more height as you start getting into the realms of an engineering operation, which would require Planning.

Please could you direct me to the relevant rule (applicable in England)?

[DevilDamo]

https://www.gov.uk/guidance/when-is-permission-required

 

https://www.planningresource.co.uk/article/1209004/operational-development-q---dcp-section-431

[Adsibob]

I think the starting point is really what is physically possible from an engineering point of view given the row of leyland cypress trees which, on my preferred layout, will just be 1 metre from the building. Once I understand what implications those trees have for foundations, and whether suitable foundations (e.g. piling) for a one storey building, perhaps slightly sunk into the ground, can coexist with the trees, or whether one will harm the other, they I can progress my thinking to tackle any planning issues.

 

Perhaps someone like @Gus Potter could chime in on the foundations question.

 

cheers!

Edited August 5 by Adsibob

[Adsibob]

e.g. not sure if ground screws like those mentioned here would work: https://www.gardenspaces.co.uk/detail/foundations/

 

[joe90]

2 hours ago, Adsibob said:

e.g. not sure if ground screws like those mentioned here would work: https://www.gardenspaces.co.uk/detail/foundations/

 

Why not? 

 

22 hours ago, DevilDamo said:

People would have to be careful if they are start reducing levels in order to provide more height as you start getting into the realms of an engineering operation, which would require Planning.

But surely we are only talking about reducing a small amount, a foot maybe 🤷‍♂️

 

yes @Gus Potter input on trees/foundations will be good (he helped me with my garage foundation ).

[DevilDamo]

2 hours ago, joe90 said:

But surely we are only talking about reducing a small amount, a foot maybe 🤷‍♂️

The OP was talking about having 2 or 3 steps down and taking into account the floor make-up, that is already going to be a reduction of at least 600mm. Should the OP decide to submit a LDC, then I’d be quite surprised if the LPA were going to ignore the engineering operations.

[Adsibob]

30 minutes ago, DevilDamo said:

The OP was talking about having 2 or 3 steps down and taking into account the floor make-up, that is already going to be a reduction of at least 600mm. Should the OP decide to submit a LDC, then I’d be quite surprised if the LPA were going to ignore the engineering operations.

Yeah, it would need to be a significant drop down.

[joe90]

1 minute ago, Adsibob said:

Yeah, it would need to be a significant drop down.

However a 600mm drop over a meter is doable with a gradient, rock garden etc without getting into structural stuff surely?

[PNAmble]

6 hours ago, Adsibob said:

e.g. not sure if ground screws like those mentioned here would work: https://www.gardenspaces.co.uk/detail/foundations/

This is what our garden room was built on.  Worked perfectly.  Especially as we were only 3m above sea level.  

[DevilDamo]

57 minutes ago, Adsibob said:

Yeah, it would need to be a significant drop down.

You’d be better going in for Planning.

[Adsibob]

On 05/08/2024 at 21:40, DevilDamo said:

You’d be better going in for Planning.

Yes, I think you are right. That involves waiting another two years so that my existing works are immune from challenge.

[Jilly]

18 minutes ago, Adsibob said:

Yes, I think you are right. That involves waiting another two years so that my existing works are immune from challenge.

It might be wise in that case not to do anything which you assume to be under PD Rights, in case someone challenges it and opens up the other can of worms? I've heard it recommended to apply for a Certificate of lawfulness to confirm you don't need planning. 

If you need a piled solution you would need BC I think.

[DevilDamo]

On 07/08/2024 at 21:12, Jilly said:

If you need a piled solution you would need BC I think.

That would not trigger BR’s. As it’ll be over 15sq.m, it would depend upon how it’s constructed. 

[Adsibob]

2 hours ago, DevilDamo said:

That would not trigger BR’s. As it’ll be over 15sq.m, it would depend upon how it’s constructed. 

I’m happy to build in compliance with the building regs. The BCO on our build was less ridiculous/illogical/unreasonable than our local planning department. And importantly, neighbours don’t get involved in the process.

[SteamyTea]

On 04/08/2024 at 17:19, Adsibob said:

maximum height of the building is 2.4m

Check the height of a multi-gym machine, or at least get some video of your fingers trapped between the handle and the ceiling.

 

You will need a bit of room between the building and the now illegal to plant trees for annual pruning.  I would not worry about damaging them, they are like triffids.