Hot/warm deck alternative

[bolst3r]

I kind of already know the answer to this but i'm after a sanity check if someone wouldn't mind assisting?

I'm looking to build a garden gym, so insulation (particularly in the summer) is key to a useable space. I've been using my DIY garden office for 10 years which has a warm deck and is amazing. Unfortunately there's limited head clearance which is fine for an office but impractical for a gym.

Due to permitted development constraints I'm unable to go above 2.5m tall, usually this would be fine but the hot/warm deck is where problems occur... I've looked online but I can't find a suitable alternative that will deal with:

1. Vapour/condensation
2. Insulation requirements
3. Give the extra height clearance

Am I missing an obvious alternative, or I overthinking this?

 

[Swwils]

Dig down.

 

[freddiemercurystwin]

No you're not missing anything, you can dig down but that's easier said than done, consider getting planning permission, no idea how viable that is from what you've posted though.

 

[bolst3r]

No you're not missing anything, you can dig down but that's easier said than done, consider getting planning permission, no idea how viable that is from what you've posted though.

I think i've decided to dig down a little, maybe only 60-80mm, and i'll change the roof and move the insulation inside, making sure to leave a small gap to allow airflow. It's a small compromise that I don't believe will have a huge impact on usability but it will give me the extra head clearance I required without having to go through the lengthy, and perhaps costly route of planning permission.