Addition Costs 

Typical costs, values and returns on investment for home additions.

Basic Room Addition Level 1
In a style and location appropriate to the existing house, add a single-story 12-by-16-foot room on a crawl space block foundation with vinyl siding and fiberglass shingles over gabled roof. Include drywall interior with proper insulation, carpet flooring, 3 all-vinyl double-hung windows, and a 36” exterior door. Tie into existing HVAC. Add electrical system to code, including 6 recessed ceiling lights.

Basic Room Addition Level 2
In a style and location appropriate to the existing house, add a 12-by-16 foot room on a crawl space brick-veneer foundation with Hardiplank siding and fiberglass shingles over gabled roof. Include drywall interior with batt insulation, prefinished hardwood floor. Include 3 exterior-clad windows, atrium-style exterior door, and two skylights. Add ductless HVAC wall system to service addition separate from rest of house. Add electrical system to code, including 6 recessed ceiling lights and one ceiling fan.

2-Story Addition Level 1
To Basic Room Addition, add a second level. Simple gabled roof tie in perpendicular to existing gabled roof . Use existing second floor window opening as access to new second floor of addition. Costs reflect percentage increase over applicable level of single-story room addition.

2-Story Addition Level 2
To Basic Room Addition, add a second level. Complex roof tie in requiring the relocation of bathroom roof vents, one existing skylight, and 2 windows. Create new, functional opening from existing second floor to new addition. Costs reflect percentage increase over applicable level of single-story room addition.

Kitchen Conversion Level 1
To Basic Room Addition, convert that space into larger, functional kitchen by combining adjoining existing kitchen space. Demo and clear out existing kitchen space. Add 35 linear feet of semi-custom maple cabinets, including a 3-by-5-foot island, solid surface countertops, and standard double-tub stainless-steel sink with standard single-lever faucet. Include removal of a 10’ partition wall to free up more space. Include energy-efficient wall oven, cooktop, ventilation system; built-in microwave, dishwasher, garbage disposal; and custom lighting. Replace flooring with high-end resilient flooring. Finish with painted walls, trim, and ceiling.

Kitchen Conversion Level 2
To Basic Room Addition, convert that space into larger, functional kitchen by combining adjoining existing kitchen space. Demo and clear out existing kitchen space. Add 40 linear feet of cherry cabinets with built-in sliding shelves and other interior accessories. Include granite countertops with ceramic or glass tile backsplash; built-in refrigerator, cooktop, and 36-inch commercial grade range and vent hood; and built-in warming drawer, trash compactor, and combination microwave and convection oven. Install undermount sink with single arm faucet and built-in water filtration system. Add general and task lighting, including low-voltage under-cabinet lights. Include removal of 12’ load-bearing wall, adding header supported by 2 decorative fluted columns. Remove vinyl sheet flooring and install oak hardwood flooring to match other rooms.

Bathroom Conversion Level 1
To Basic Room Addition, add a walk-in closet and 9 by 9 feet bathroom. Add tub with custom 4-by-6-foot shower with single valve and 3 jetted sprays, ceramic tile surround, and glass door. Add toilet, medium-range stone tops in maple vanity cabinet with undermount sinks and polished nickel faucets. Include ceramic tile floors and hardwood trim. Add general and spot lighting and a humidistat-controlled exhaust fan. Standard tie in to existing plumbing under accessible crawl space of existing house.

Bathroom Conversion Level 2
To Basic Room Addition, add a walk-in closet and 10 by 12 feet bathroom. Add tub with custom 4-by-6-foot dual shower with top-of-line fittings and full-body-wash shower wall, tile, glass block divider, glass door, and glass panel. Add toilet, granite stone tops in custom cherry cabinet with twin designer undermount sinks and polished nickel faucets. Add step-in linen/towel storage closet. Include ceramic tile floor, chair and crown molding, and hardwood trim. Add general and spot lighting and a humidistat-controlled exhaust fan w/ heater.

*Source: RemodelingOnline