Add On to Home

Ideas, costs, tips and plans - the information you need for a successful Home Addition project

March 2015

Homeowners have many important questions about their Home Addition Project. How much will it cost? How long will it take? What problem areas do I need to watch out for? Can I recover my Home Addition investment when I sell? Can I do some of the work myself? What can I do to make sure that the work is done right?

Costs, materials and best practices for the example Home Addition project will help you answer these questions. Use this information to develop a budget, bid requirements, hiring contracts and a project plan.

Home Addition - Project Overview

The approximate costs and value of a typical Home Addition project are summarized below. Use higher estimates for larger metropolitan areas and the lower estimates where home prices are below the national average. Adjust costs for substitutions or refinements in the last section. For size differences of up to 25%, scale total costs in direct proportion to the size of your project. Use the adjusted costs as a basis for setting a material budget and for comparing contractor bids (if you choose to have a professional perform the work).

Project descriptionExtend house foundation. Frame addition structure. Add electrical.Insulate and finish walls. Include surface finishes. Average to above average quality.
Project size250 square foot room addition /expansion
Material and labor cost$23,832 - $27,804
Material cost$14,108 - $16,459
Do-it-yourself assessmentThe typical Home Addition project involves tasks that are best performed by experienced professionals. Good quality Home Addition requires considerable experience, skill and attention to detail. Do it yourself mistakes are noticeable, may be difficulty to remedy and may actually reduce the market value of the project and your home.
First year Return on Investment - ROIReturns vary widely and are affected by the range of home prices in your neighborhood, the overall condition of your home and sensible design choices. A high quality Home Addition project in an appropriate neighborhood can return as much as 77% - 91% of its initial cost.
First year Return on Investment - ROIReturns will be impacted by the range of home prices in your neighborhood, the overall condition of your home and sensible design choices. A high quality Home Addition project can return as much as 67% - 78% of its initial cost
Green ratingHome Addition projects can employ renewable resources and environmentally friendly construction materials. Efficient lighting, HVAC, insulation and appliance choices can significantly reduce the energy footprint of your home.

Home Addition - Project Plan and Details

The following list includes major work tasks commonly performed during Home Addition. Use this list to understand the timing and sequence of different steps in the Home Addition project. Click any Task name for a complete written specifications, FAQs and quality checklist for the task - this essential information will help you control Home Addition project cost and quality.

Do you expect to spend more than $250 on your Home Addition project? If so, it is important create and manage a detailed plan for all project activities.

TaskService ProviderTimeDifficultyBasic Cost Range
Create Working DrawingsArchitect5 to 15 d$1,458 - $2,435 per design
Install SubfloorCarpenter1 to 2 d$6.13 - $10.77 per square foot
Frame Interior WallCarpenter1 to 2 d$2.79 - $4.99 per square foot
Frame CeilingCarpenter1 to 2 d$3.18 - $5.65 per square foot
Install DuctHVAC Contractor1 to 2 dLevel 3 - Complex, Difficult$6.89 - $12.15 per linear foot
Upgrade Electrical Service PanelElectrician1 to 3 dLevel 4 - Pros Only$871 - $1,526
Install Lighting CircuitElectrician1 to 2 dLevel 4 - Pros Only$341 - $581
Remodel Electrical BoxElectrician1 to 3 dLevel 2 - Challenging$506 - $916
Insulate Your HomeInsulation Contractor1 dLevel 2 - Challenging$0.79 - $1.37 per square foot
Install DrywallDrywall Contractor1 to 3 dLevel 2 - Challenging$1.28 - $2.24 per square foot
Texture DrywallDrywall Contractor1 to 2 d$0.96 - $1.67 per square foot
Install Wood WindowFinish Carpenter1 dLevel 2 - Challenging$382 - $685
Install Prehung DoorFinish Carpenter1 dLevel 3 - Complex, Difficult$203 - $358 per door
Install Trim MoldingFinish Carpenter1 to 2 dLevel 2 - Challenging$3.18 - $5.58 per linear foot
Paint Trim MoldingPainting Contractor1 to 3 dLevel 2 - Challenging$1.23 - $2.10 per linear foot
Paint RoomsPainting Contractor1 to 3 dLevel 2 - Challenging$3.83 - $6.53 per square foot
Install Hardwood FloorFlooring Contractor1 to 2 dLevel 2 - Challenging$7.83 - $13.90 per square foot
Install Electrical OutletElectrician1 dLevel 2 - Challenging$100 - $170
Install ThermostatElectrician 1 to 3 dLevel 2 - Challenging$165 - $290
Install Lighting FixtureElectrician1 to 2 dLevel 1 - Basic$121 - $211


Home Addition - Proven Ideas and Project Tips

Review these tips, design suggestions, options and lessons learned before finalizing your Home Addition project plan.

  • To maximize return on the Home Addition project, limit cost to no more than 21% of home's total, post project value
  • For best home resale value, follow a consistent design and decorating theme throughout the home
  • Perform major Home Addition work with permits to help protect value at resale time
  • Match appliances and fixtures to electrical circuit, hot water and gas capacities
  • Understand how your project will change property taxes (assessed value) and home insurance - before the project begins

Home Addition Project Guide

Project Plan: Home Addition

Do you expect to spend more than $250 on your Home Addition project? If so, it is important create and manage a detailed plan for all project activities.

This FREE homewyse project guide helps you organize Home Addition project activities, effectively manage milestones and costs - and get quality work at a fair price.

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