Garden office

[ban-all-sheds]

Exemption class 6,1 (>30sqm) only applies when the building is 1m from the boundary,
if you're within 1m the applicable exemption is Class 6,3 which is >15sqm,
the OP described his intention to build across the entire width (less than 1m clear of boundaries), therefore he is working under exemption 6,3 not 6,1.

Admittedly I could have phrased it better initially.

So could I

Sorry

6.1 makes the limit 30m² if no point of it is less than one metre from the boundary of its curtilage OR it's constructed substantially of non-combustible material, which the OP's will be.

 

[masona]

The way I did my summer house/workshop/shed was to use nuts/bolts 2nd hand pre-cast slabs, it's fireproof and maintenance free and easier to put up with limited room, I've left a 150mm gap between the fence panels for airflow

 

[masona]

Forgot to add, doesn't look like a pre-cast shed, I've covered it with log cladding!