COST ESTIMATING for RESIDENTIAL GREENHOUSES
WSD Rule of Thumb
Most clients spend the amount they would pay for their new auto. Some have spent as little as $2,500.00, others as much as $340,000. The cost of lean-to greenhouse structures may be estimated at $150/SF to $300/SF as modified by factors noted below. Add an additional 20% to 50% to this cost range for free-standing greenhouses depending on the geometric shape, volume enclosed and the factors below.
What Do Most Clients Want for this Money?
They want a rectangular single sloped one story greenhouse approximately 150 to 200 SF. Cost increases with complex shapes, higher eaves, expensive finishes, specialized equipment and environmental climate controls.
You don’t have to squeeze your greenhouse dream to fit a warehouse inventory of prefabricated kits. We design each project to fit your wishes rather than warehouse “on the shelf” precut stock. Our licensed structural engineering and architectural planning assure you of a design that enhances your home, is individual and complies with government codes. The design process holds down expenses and improves results.
Costs per sq. ft. are greater for smaller projects, less for larger projects. Add or deduct to the average range about 20% for very small (<100 SF) or very large projects (>1000).
Most heated greenhouses have insulating glass with a low-e and argon gas filled air space. Cost for this glass is considered average in estimating and is included in the typical cost per square foot estimate. Single glazing, rarely used for heated structures, costs about $5 less per SF.
Special coatings, tints, ceramic frit, heavy glass and non-rectangular shapes add costs ranging from $2 to $30 per SF.
Finish on the Framework and Flashings
Most greenhouses are finished in a standard anodized or painted color which is included in the median cost range of about $200/SF. Special colors add cost and painted fluoropolymer finishes cost considerably more than anodized. The amount of metal and overall size of the project determine the cost of these finishes. A non-standard color painted finish will add about $3,000.00 to the typical 200 SF greenhouse.
Specialized equipment and furnishings for facilitating plant growth include: automatic operable roof vent sash, planting benches, shading, watering system, sidewall venting, grow lighting, evaporative cooling, fans, planting supplies and a headhouse area equipped with a sink, storage space and working surfaces. The basic and most essential greenhouse equipment is included in the estimate averages. Essential start-up equipment chosen by most clients includes basic climate controls (i.e., the operable roof vent sash) and side wall ventilation. Shading and benches are often added later once the structure is operational.
A full five-year glass warranty and two year no-cost service warranty are included on all factory authorized installations. Add 5% for a 10 year glass warranty.
Special Structural Requirements
A greenhouse may impart structural loads on an adjacent supporting structure which may call for some modification. Such structural considerations increase the cost.
Technical AssistancePlease contact us directly for specific assistance in pricing your greenhouse.