Accounting policies - Comparative amounts (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Accounting policies
Revenue	$ 35,118,706	$ 33,390,557	$ 102,425,170	$ 105,559,105
Services
Accounting policies
Revenue	$ 14,289,315	12,677,837	$ 35,815,785	42,017,917
Services | Design and consulting revenue | Previously issued
Accounting policies
Revenue		614,199		1,467,461
Services | Construction revenue | Reclassified
Accounting policies
Revenue		$ 614,199		$ 1,467,461