How can I build a glass roof,a solarium or a greenhouse. Is it possible to built a 45 degree stairs :?:

SimPE is kind of a back end utility to enhance or hack Sims2, you cant really "build" anything with SimPE.

You would have better luck trying to find what you are looking for at modthesims2.com. There you can find all kinds of useful tutorials from building, decorating and even using SimPE not to mention lots of helpful people to answer questions on just about any topic. Be sure to utilize the search function as there is a ton of information that may be what you are looking for already asked and answered. hope this helps :)