While adding a clubhouse is not normally a great idea in a mobile home park, we are currently remodeling one in a park we own in Austin, and I understand the need to feel that you are giving back to the community to justify a rent increase. Most of the clubhouse additions that I see to parks today are double-wides that are adapted for that use. Clayton makes some fine models that are not too expensive (figure maybe $40,000 if you're a good shopper). That way the clubhouse arrives ready to go, matches your product, and you can have the whole project done in 90 days or so. But be sure to check with your city and make sure that a mobile home can be used for the clubhouse (since that's not a mobile home lot and will be used for commercial activity).