How much does it cost to build a sunroom?

Adding a sunroom to a home can mean extra living space or simply a three-season room that becomes a great deal more hospitable than the average porch or deck. For this discussion we will consider the costs and requirements of adding a 200 square foot (roughly 14'x14') sunroom suitable for year-round usage. This is not a project that can be considered a "DIY" project due to the fact that it connects to the existing structure and requires the use of several types of contractors including concrete pourers, electricians and carpenters.

To build a sunroom, the typical costs include:

• According to Hanley Wood and their "Remodeling" magazine the average sunroom addition in which a slab is poured, post and beam construction is used, and a four-season space is created will cost $72,000. The resale value of this update would hold at $51,840, or a nearly 72% return on investment.

• The above figures place the sunroom addition at $360 per square foot. This pricing structure assumes that carpenters charge an average of $70 per hour, electricians between $65 to $85 per hour, and painters between $20 and $35 per hour.

Cost breakdown

What needs to be included:

• Arrange for any required demolition, excavation, or site preparation - Average costs are going to vary according to the level of work necessary;

• Pour concrete footings and slab/on-grade foundation - Average price of concrete is $75 per cubic yard, with piers and the full slab it would require roughly 30 cubic yards and would cost at least $2500;

• Build post-and-beam framing, with roof trusses and support beam system exposed on interior side, and tie into existing house - lumber prices will vary as will the design used by the carpenters constructing the sunroom. The project should require 2x4 wood framing suitable to accommodate glass doors and windows as well as any interior finishing requirements;

• Install vinyl or aluminum clad casement windows with low-E, laminated or tempered glazing and screens - Average cost of $240 each, with three hours of installation per window, for materials cost of $2400 (this does not include time or materials for construction of knee wall around perimeter of the room);

• 10 large aluminum-clad venting skylights with screens - Average cost of $425 each with three hours of installation per window (this does not include time or materials for construction of roof structure);

• Install and seal quarry tile on floor - Average cost of $6 to $10 per square foot, installed. With professional installation and finishing this would cost roughly $1200;

• Install and wire outdoor ceiling fan - Average cost of $219 to $400 plus four hours of electrical work;

• Finishing and insulation of all non-glass areas - Average cost of 4'x8' panel of drywall is $9.80 and standard insulation will average $1.10 per square foot accordingly (this does not include cost for professional installation and finishing);

• Install bead board ceiling - Average price per bundle (6 boards at 8' lengths) $30. Total cost $240, plus installation time of roughly 12 hours;

• Moldings - Average of $3.00 per foot of installed molding for a total of roughly $750 to complete framing around all doors, windows, and skylights;

• Provide electrical wiring and lighting to code - This is going to depend upon the amount of work required, but electricians average from $65 to $85 per hour. This project might be priced on a per item basis, or the electrician might simply base it on the square footage; and

• Provide carpentry to code - This is going to depend upon the amount of work required, but carpenters average $70 per hour. This project might be priced on a per item basis, or the carpenter might simply base it on the square footage.

Enhancement and improvement costs

• Installation movable shades for glass areas;
• Installation of supplementary heating system;
• Installation of gutters and eaves;
• Include stairs, assuming three steps to grade; and
• Painting or staining.