Chapter 1 -- Getting Started.
This is a big project, especially if you work full time and, depending on how it is scheduled, can drag on for years. We stretched ours over two years and we still haven't completed the
accessories or the air distribution system. Set realistic expectations, give yourself plenty of time, and watch it grow!
Select a Plan - Try to get the biggest greenhouse that will fit your space and pocket book. Each plan should have a BOM and an estimated cost to build.
Before you spend any more money,
use the checklist below:
Check local building codes,
determine if there are any deed restrictions, look-up any set back requirements and easement regulations.
Layout the whole yard and the house.
The greenhouse or conservatory will probably become the dominating structure in your yard.
your time and money. The total cost can vary substantially depending on choices you make early on – single or double pane, treated wood or cypress, salvaged materials or new, build yourself or hire some one. We built the foundation and the main room the first year, wrapped it in plastic, and used a propane heater to keep the plants from freezing. The second summer, we completed it.
Provide the Bill of Material
to your local lumber yard, glass contractor, or general contractor and get an actual estimate. If you're doing the work yourself, you'll need probably 8 long weeks with a helper to do all the work. [For sample BOMS (most of my plans have them) click <more info.> on the Orders or Plans pages].
Locating the Greenhouse
Assuming you live in the Northern Hemisphere, the ideal position for the greenhouse is where it will:
get full sun in the winter when the sun is low in the south and
get shade in the summer when the sun is overhead.
Where the house sits, how tall it is, and where trees are, should
determine the location. The winter is critical and the less shade on the greenhouse the better.
There are many reasons why you may want (or need) to change the design:
Attaching to an existing building; or
Using Different Materials.
Warm Climates: This greenhouse was built in a mild
climate with short winters and an occasional freeze. We opted for no insulation and single pane glass. The raised slab is to prevent flooding due to regular torrential rains. Natural gas is
readily available and relatively cheap and for as little as we need to heat the greenhouse, the low energy cost made the single pane glass very affordable and practical. However, with
the long hot summers, the greenhouse turns into a kiln and we move all the plants out around the pool and walks. I am investigating building a hybrid evaporative cooler / air
conditioner for summer use but I wont be able to trial the design for a year or two (the next century maybe!) See HVAC sketch in the plan packet.
Cold Climates:Double or triple insulated glass, insulation,
and foundation modifications should be considered. Perhaps, the back wall, if on the north side, could be built into a hillside or attached to a shed / house to cut down on the glass and
heat loss on the shaded side of the building. If this option is explored, drainage, aesthetics, and structural integrity must be carefully considered.
2. Local Building Codes
Since this is unoccupied space, some building codes may not
apply. However, it's best to discuss the project with your local planning department (city or county) to determine if a permit is required and determine how far from the property line the
building must sit. The "set back" requirements vary between cities, districts, counties, zones, and side, front or back property lines.
Gas piping and electrical wiring are two of the most dangerous
aspects of the installation and improper installation could result in death or loss of property. An expert is often the safest way to go, although they can make mistakes, too. The
purpose of the permit / building inspection is to help insure safety and good building technique.
A fourth wing could easily be added to the design to provide a
walkway between an existing building and the greenhouse.
Another option would be to cut the structure in half and attach it to a long flat wall.
A third option would be to wrap around /offset from the corner of your house.
An attached "sunroom" would probably count as square
footage and, thus, add more to the "appraised" value to your home than a free standing greenhouse. In our recent appraisal, the conservatory, shed, brick patios, landscaping,
etc. only added $2,000 to $5000 to the value of the home. The pool only added $3000. The single pane glass alone cost $6000 installed. If you're looking at this project as an
investment, don't. My 3D Home Architect by Broderbund quotes two conflicting articles on the cost versus value of a greenhouse. According to the National Association of Realtors
, the resale gain of a green house is 10% of it's cost:
A few years ago, this addition was more popular than it is today. In a cold
climate, a greenhouse may serve as an energy-efficient sun space in winter, but warm-weather months make it very uncomfortable without air
conditioning . . .. * Rate of return will vary depending upon locale and trends.
A Chicago-based magazine, Remodeling Contractor,
estimated the resale gain of a greenhouse at 89% of it's cost. My experience says 10% according to the appraiser. If I ever move, I'll give the purchaser the option to buy it for
replacement cost. If not, I'm disassembling it and taking it with me! They can use the concrete pad for a gazebo. It was too much work and cost to give away to a stranger.
Using Different Materials
Cypress, treated lumber, redwood, cedar, aluminum, or
coated steel would all make adequate materials for the frame/trim work.
Cypress was the most economical because I had an available
source*. However, it was rough cut and had to be run through a joiner. This was heavy work for two semi-fit adults. Un-dried cypress is very heavy and likes to hold water. It shrinks a lot in
it's width as it dries but not much in length. Let it season for a summer or two before installing glass!
is the most readily available but will probably bow and twist as it dries. You may want to let it the frame season for the summer before painting and installing glass.
Redwood and Cedar make excellent framing choices.
Aluminum or steel construction would be expensive but
there are a few companies that do beautiful work with these materials. The resulting greenhouse would probably last a lifetime (or two). A welded structure out of 4" square tubing
could be quite spectacular.