The tiny houses are arranged around a little U-shaped boardwalk. They're lovely, brightly painted, and each have different features (e.g. one tiny house has a pretty large fridge, some have interior doors instead of curtains, etc.) Mine had no fridge (at the time), and curtains for the bedroom and bathroom doors, and a hot plate to cook on. There is no wifi (when I stayed here). The water is unheated, but you don't need hot water.
By Belize standards, it felt a little strange to stay someplace that didn't have dogs, chickens, or some form of domesticated animal roaming around. :)
The only downside I experienced was the extremely muddy road to the houses - it consistently challenged my 4wd to get back out of the rich slippery mud. But Carren's planning to put in the road as soon as it dries out from the recent (prolonged) rainy season, so it may be fine by the time you stay there! There's an outside tap on each tiny house, so you can probably use that to hose off shoes if desired.
Carren was extremely responsive in helping me get to the tiny houses and get checked in, and gave me plenty of tips about finding stuff in the city and lore about Belize and local plants and animals.
While Belmopan isn't particularly interesting unless you're going to museums or people-watching, I'd definitely stay here again once the road is less muddy.