During the past four decades, the National Greenhouse Manufacturers Association’s (NGMA) structural manufacturers have worked with growers from all over the world. Whether it’s at a greenhouse or a trade show, they have found there are some common questions growers ask. So, the NGMA collected answers to the most frequently asked questions. The questions are basic, the answers simple, but the information should be helpful.
What does a greenhouse cost?
Probably one of the most common questions the association receives is regarding costs. Unfortunately, there is no quick answer to the question. A better question is, “What would a greenhouse cost that ﬁts your speciﬁc needs?” Cost is not easily determined, because greenhouses vary due to local codes and zoning, the purpose for the greenhouse, its geographical location and future expansion goals.
What should a grower do ﬁrst before purchasing a greenhouse?
Before purchasing a greenhouse, the first thing to do is to contact the zoning authorities. Because zoning varies from one county to the next, one greenhouse may have a totally different situation than a greenhouse just across the street. Simply put, each location is different and there is no basic answer.
While the United States recognizes 50 state governments, there are more than 87,000 local governments. The possibilities of code and zoning combinations are endless. Zoning codes and building requirements can be any mix. The laws are becoming stricter, and the negative consequences of noncompliance are worse. We cannot stress enough the importance of checking with your local planning authorities before doing anything.
What authorities do I contact before purchasing a greenhouse?
First, check with your zoning authorities for your speciﬁc location’s setbacks, building material requirements and allowed businesses. Second, talk with the planning commission regarding building codes. Ask them what code body they recognize and for which year. Also determine if stamped and licensed drawings by an engineer are required. If applicable, also ask what the wind and snow load requirements are for a greenhouse. Then check with the ﬁre authorities on what they require for greenhouses.
While greenhouses are unique, they often are not treated as such. Find out all their ﬁre codes, speciﬁcally sprinkler system and covering requirements. The tough questions should be answered before designing a greenhouse, not after. While these questions may seem overwhelming to the new grower, there is help available through any of the National Greenhouse Manufacturers Association’s structural members.
What exactly is a non-code house?
The simplest commercial greenhouse is referred to as a cold frame. Cold frames are designed for overwintering crops and for shade. They are considered temporary and do not meet codes. Cold frames are very basic, but can have some signiﬁcant variables. While they are non-code houses, cold frames can still have structural strength as they are built with steel tubing.
How do non-code houses vary?
When growing crop on the ﬂoor, sidewall height is not necessary. However, if you’re growing crops on benches, sidewall height is very important. Height is also an issue if any overhead equipment is to be hung from the structure.
For more information, including details on fire code issues and the differences between retail and production greenhouses, read Purchasing A Greenhouse on the NGMA site.