Most of the students don't seem to need much help; it's as much an artistic effort as it is a practical one. Sticking charms are quite basic, and these are older students, so most of them are able to get their parts to stick, but more than half the houses are ugly as sin. And that's fine, it's not as if the flitterbys care, and Sirius gets a good laugh out of the lopsided monstrosities that some of them are putting together.

The heat source is, of course, the real challenge, trying to find the balance between too much heat and not enough, and not placing it against or near any flammable surfaces - half the tables have scorch marks on them by the time he's drawing up to Adrian's side, once he's tugged over.

"Oh, pretty," he remarks with raised eyebrows, lifting the little glass house and turning it over in his hands, little spots of refracted light dancing on the tabletop. He's listening, though, and once the boy is finished, Sirius is frowning thoughtfully.

"Like a battery." Like as not, Sirius is quite possibly the most well-versed of any of the pureblood professors in muggle items and how they work. "A warming charm would be easy, sure, cast it on something and place it inside. But you'd need to think of some method to keep it from wearing off." And he can't go giving out easy answers, of course. "Using the sun would be quite easy, since you've made it out of glass. Smart. Might not need a warming charm at all if you can trap it well enough."