Estimating Rehab Cost: The Complete Investor’s Guide

How to Estimate Rehab Cost

Before even starting a Fix-and-Flip project, it’s very important to determine the After Repair Value of the house and the Total Rehab Cost, check our free House Rehab Estimator here. Of course, there are other expenses to consider but these two will show you if the house is even worth buying.

Investors use different ways of estimating rehab costs. Here are the three most commonly used methods.

  •  By the square footage: It’s used by highly experienced investors. It’s fast but doesn’t give you enough information, so it’s a rough estimation that gives you a basic idea if a project is worth starting.
  • By the room: Same as the above method, this one works for rehabbers who have gone through a lot of projects and can roughly tell the rehab cost by just looking at it and knowing the number of rooms.
  • Item by Item: This method will give you probably the most accurate estimate. By doing a thorough inspection and following a checklist, you almost eliminate the risk of encountering unpleasant surprises during the rehab process.



The first thing buyers notice and ask about is the condition of the roof.

If you want to sell the property to an FHA or VA buyer, you have to make sure the roof has at least a couple of years of useful life left: 2 years for FHA and 5 years for VA. 

Sometimes, if you are lucky, the roof is newer but this doesn’t mean it hasn’t failed its main function, keeping water out of the house. You still need to thoroughly inspect the roof:

  • Wet or yellow stains on the ceiling are the first signs of a leaking roof. Although yellow spots could be left by previous already fixed leaks or from AC vent condensation. The previous owner just didn’t paint them.
  • If you have access to the attic, climb in it and check the roof sheathing for rot and wet spots.
  • The most common roofs today are covered with asphalt shingles. Look for major discoloration spots, bare spots, missing shingles, or curling shingle edges. 

You can decide whether to replace the roof by checking how old it is:

  • Asphalt shingles last around 15-25 years.
  • Wood shingles around 40 years
  • Metal roofs around 80 years
  • Slate roofs more than 100 years
  • Clay roofs more than 50 years

To get an estimate for the roof replacement, first, calculate the roof size. An easy way to do this is to multiply the outside width of the house by its length and you’ll get the base square footage.

Next, multiply the result by two and you’ll have the roof area in sq. ft.

Since shingles are sold “square” and one square is 100 sq ft, divide the roof area by 100 and you’ll find how many squares you’ll need.

For example, 30 ft x 50 ft = 1500 sq ft. 1500 sq ft x 2 = 3000 sq ft (roof area in sq ft). 3000 sq ft / 100 = 30 squares (roof area in squares.)

What are your choices if you discover a roof leak or two?

Depending on the roof condition and age, you have two choices:

  • Repair it. This includes fixing flashing issues, nail pos, nailing down loose shingles, etc. which cost around $500.
  • Replace it. Don’t fall for the temptation to go for the shingle-over-shingle option to save some money. Some states like Florida, allow it but many roofing contractors refuse to do it because of liabilities.

The roof replacement cost (including materials and old shingles removal) should be in the range of:

  • $180-$350 per square for asphalt shingles
  • $450-$700 per square for wood shingles
  • $350-$900 per square for steel roof
  • $750-$1,000 per square for aluminum roof
  • $1,000-$3,000 per square for slate roof

Roof sheathing. One of the many reasons not to go with the shingle-over-shingle option is that when the roofer tears down the old shingles they will see if some the sheathing needs to be replaced. The price should be around $50 per OSB/plywood sheet.


To assess the condition of the gutters, soffit, and fascia, you just need to visually inspect them. Look for rusty spots, holes, rot, peeling paint, missing or damaged downspouts, or any visible physical damage. Also, if the gutters have a lot of debris collected on the opposite side of the downspout, its slope must be adjusted.

Use our free estimator to find out the average cost of replacing gutters, soffits, and fascia based on the materials and the size of your property.


Inspect wood siding for damage, rot (mostly above the window and door frames), split wood planks, moss growing, etc. Check vinyl siding for visible damages and if you can take a peek behind the siding, see if there is house wrap between the siding and the sheathing. Similarly to the roof, you can decide to replace the siding by considering its age:

  • Wood: around 30 years
  • Aluminum: around 30 years
  • Vinyl: around 40 years
  • Cement composite: If not damaged, more than 40 years
  • Masonry: If not damaged, more than 100 years

Exterior Walls Repair and Maintenance Cost:

  • Pressure wash: $200-350 (depends on the house size) If you are not replacing the siding, this must be done even if you are planing to paint the exterior.
  • Remove the old siding: $50-100 per square (not square foot)
  • Replace sheathing: $40-50 per OSB/plywood sheet
  • Replace house wrap: $300-600 for the whole house
  • Patch siding: $3-6 per square foot. If the area is too big, patching is a lot more expensive than replacing the siding of the whole area.
  • Replace siding (please note that the prices of all types of siding except for Masonry are per square, not square foot):
    • Wood: $400-$700 per square
    • Aluminum: $200-$350 per square
    • Vinyl: $150-$350 per square
    • Cement board: $300-$600 per square
    • Masonry: $15-$25 per square foot

Exterior Painting

  • Paint exterior including trim: $1.50-$3.00 per square foot of interior floor
  • Paint only trim: $0.50-$1.00 per square foot of interior floor

Decks and Porches

Since there are codes associated with building wooden decks and porches, it is recommended to hire a licensed contractor to inspect the deck but if you don’t, there are some elements that you can look for:

  • Is the deck correctly attached to the house
  • Are the supporting posts in good condition: no rot, growing moss, or any insects eating through them.
  • Are the posts attached to the concrete footers or just resting on them
  • Are there concrete footers at all
  • Is the size of the posts adequate to support the deck (at least 4”x4”)

Building a new deck or porch should be around $18-$30 per square foot.

Concrete Driveways, Patios and Walls

You can visually inspect the condition of the concrete structure. Look for big cracks, bowing walls, etc. Repairing or building a new driveway, wall, steps, deck, or other concrete structure will be around $5-$10 per square foot.

Garage Doors

Wood doors: Inspect the condition of the wood. Inspect the condition of the springs: detach the door from the opener and lift it manually. You should be able to do so with little to no effort. The same applies to aluminum doors.

Safety: Press the wall or remote button to close the door and try to stop it by hand. If you are not able to do so, the opener is missing this safety feature or is misconfigured.

Next, look for the presence of the “safety eyes.” (small camera like devices located at the bottom of both sides of the door frame) Put something underneath the door and push the button to close it. If the safety eyes work correctly, the door won’t close and, in most cases, the opener light will start blinking and you will hear clicking noises(an indication that a safety feature is engaged)

Overall condition: Visually inspect the door for damages. Sometimes, you need to replace just one or two sections of the door, not the whole thing.


Replace a garage door:

  • Single door: around $600
  • Double door: around $1,200

Replace a door opener: around $400


It’s a good practice to mow and edge the lawn, trim bushes and trees, and remove any tree that needs to be removed before even starting to work on the house. This for the safety of the workers and the house will start looking better.

  • Lawn: a one-time cut is around $80. Of course, if the expected length of the project is several months, it will be a good idea to hire a company to maintain the landscaping.
  • Trim bushes: around $60
  • Trim: tree: around $200 (depends on how tall the tree is)
  • Remove tree: $100-$1,500 (depends on the size of the tree)
  • Install sod: around $2 per square foot

Build a retaining wall:

  • Concrete blocks: around $50 per sq ft of wall
  • Wood: around: around $40 per sq ft of wall
  • Stone: around: around $50 per sq ft of wall
  • Poured concrete: around $50 per sq ft of wall

Septic System

Inspection: The only thing you can do by yourself is to look for fluid (not rainwater) puddles around the house and in the backyard, look for sewer smells around the house, back yard, and in the bathrooms.

Leave all faucets running and flush the toilets. If some or all of the drains start backing up, it could be an indicator of septic problems.


  • Inspect and clean the septic tank: $300-$500
  • Major septic repairs: Depending on the severity of the problem, the price could start from $1,000 and top $10,000


Inspection: Here some items you should look for:

  • Large cracks on the floor. Can you stick a quarter in the crack?
  • Large cracks on the walls. In block construction look for staircase cracks.
  • Doors don’t close or get stuck
  • Basement (if any) walls are bowing or cracked

If you see some of the above, the best way is to consult with an engineer (around $150 per hour). Depending on the extent of the damage, the price for fixing the problem could reach $10,000 and more.



  • Dumpster: $350-$600 (depends on the size)
  • Demolition: $0.5-$1.00 per square foot
  • Porta-potty: around $200 per month



Well pump:

  • If the pump is constantly running or it turns on without having any faucets open, there probably is a leak somewhere along the supply lines.
  • The best approach is to hire a qualified company to check and service the well system.
  • Get the water tested.

County or City water: If the house water is supplied by the county, you can check for leaks by closing all the water valves in the house and looking at the water meter. If some of the water flow indicators are spinning even slowly, there is a leak somewhere.

Water heater:

  • Check the sticker or plaque attached to the water heater to determine its age. If it’s more than 8 years old, it’s good to be replaced.
  • Look for major rust build-up at the bottom of the heater or the heating elements covers. If this is the tank is leaking so the water heater must be replaced.

Drains: To check the drains, leave all faucets running and flush all toilets (simultaneously if can)

Check for water damage on the ceiling and under sink cabinets.

Plumbing Repairs Cost:

  • Replace the main supply line: $1,500-$3,000 (depends on its length and accessibility)
  • Replace the PRV (pressure release valve): $150-$300
  • Replace water heater: $550-$1,000
  • Replace supply lines: $250-$350 per fixture (faucet, valve)
  • Install shower/tub (fiberglass kit): $550-$1,100
  • Build a tile shower: $25-$40 per sq ft of the tiled surface
  • Replace bathroom sinks: $80-$160 each
  • Replace a kitchen sink: $150-$250
  • Replace bathroom faucets: $80-$110 each
  • Replace a kitchen faucet: $130-$270
  • Replace shower/tub hardware: $90-$350
  • Replace toilets: $160-$300 each
  • Replace the washer water supply box: $150-$250
  • Fix leaks: $50-$500 each


Inspection: Although it’s necessary to have a licensed electrician inspect the electrical system, there are several items you can check by yourself:

  • Get yourself an outlet tester and randomly check several outlets throughout the house. If there is at least one miswired, you can expect more electrical problems.
  • Test all GFCI outlets
  • Check if all of the outlets are three-pronged
  • Check all lights, fans, and appliances


  • Upgrade the electrical service (if you are planning upgrades that will require more power than the existing system can handle or if the existing system doesn’t offer 250V option): $1.200-$2,500
  • Replace the power box: $800-$1,500
  • Rewire the house: $50-$100 per switch, outlet, or fixture
  • Add new circuit: $125-$250 each
  • Add a new outlet: $60-$100 each
  • Upgrade an outlet to GFCI: $30-$50 each
  • Add a new switch: $100-$150 each
  • Install a recessed light: $60-$100 each
  • Install a light fixture: $40+  (depends on the fixture price)
  • Install a fan: $70+ (depends on the fan’s price)
  • Replace an outlet/switch: $5-$10 each

Troubleshooting Electrical Problems DIY GUIDE


This is how to determine what size of furnace you need:

Warmer climates: BTU = (square footage of heated space) x 25

Colder climates:    BTU = (square footage of heated space) x 35

This is how to determine what size of  air conditioner you need:

Tons = (square footage of heated space) / 500

Inspection: Unless you are a professional A/C technician, all you can do (other than check if the system works at all) is to ensure that the handler’s condensation drain line is not clogged, and inspect the air filter inside the house.

The best approach is to call an A/C company to thoroughly inspect the unit. Expect a $150-250 charge if nothing needs to be replaced.


  • Install a forced-air system: $5,000-$8,000
  • Replace a furnace: $1,000-$2,000
  • Replace compressor: $1,2000-$2,000
  • Replace compressor and evaporator coil: $1,800-$3,000
  • Replace a heat pump: $2,000-$3,5000

Troubleshooting HVAC DIY GUIDE


  • Frame walls: $10-$20 per linear foot
  • Frame house or addition: $10-$24 per square foot


If you have access to the attic, you can visually inspect if there is enough insulation. If the insulation is rolled, it should be between R-30 and R-60, and if it is loose-fill, it should be 10 to 20 inches thick. Walls are difficult to inspect unless you rip a piece of drywall off.

Install insulation:

  • Loose-fill: $1-$2 per square foot
  • Rolled: $1-$2 per square foot
  • Rigid board: $1-$2 per square foot
  • Spray foam: $2-$5 per square foot


You can visually inspect the drywall for damages or bad repairs and taping. Check for any bad odors especially pet urine and cigarette smoke. It’s difficult and even impossible to remove these odors even with paint.

If the home was built between 2006-2007 and you can smell rotten eggs, check if the drywall is not defective Chinese drywall.


  • Prepare the drywall for painting: $0-$500 (depends on its condition)
  • Install new drywall: $1-$1.50 per square foot of drywall
  • Apply texture: $0.05-$0.25 per square foot of drywall




  • Should open and close easily, without getting stuck
  • Should latch without forcing them
  • When unlatched and partially open, the door should stay at that position without opening or closing by itself.
  • Look for extensive damages that will be time-consuming and expensive to repair


    • Should open and close easily
    • When open, the window should stay open without assistance
    • When closed, you should be able to latch it without forcing the latch or the window
    • Look for damages (broken or cracked glass, damaged frame, etc.)


  • Carpenter labor: around $35 per hour
  • Install a door:
    • Exterior door: $250-$480
    • Interior door: $70-$140
    • French door: $450-$800
    • Sliding glass door: $450-$850
  • Install a window: $850-$1300
  • Finish trim:
    • Labor: $1-$1.50 per square foot

Materials: $0.75-$1.5 per linear foot

Interior painting

Visually inspect the walls and the ceiling for damages. If there are only small holes, nail, and screws, the painters will fix them as part of the prep work.


  • Same color or light to dark color: $1.50-$2.25 per square foot of interior floor space
  • Dark to light color or new drywall: $2.0-$3.0 per square foot of interior floor space

Cabinets and Countertops

Install kitchen cabinets: $140-$320 per linear foot

Install bathroom vanities: $175-$500 per vanity

Install countertops:

  • Laminate: $18-$25 per linear foot
  • Granite: $35-$50

Tip: Consider using RTA cabinets to save money and get better quality. If you are not an interior designer, let the company design it for you. 



Carpet: look for damages, stains, and pet urine odors. Also if the house is more than 50 years old, take a peek under the carpet to see if there an originally installed hardwood floor that can be refinished.

Wood: look for scratches, water damage, or bad installation that can’t be fixed.

Tiles: Look for chipped, broken, or cracked tiles. There is a little to no chance that you’ll be able to find the same color tiles. In most cases, this means redoing the whole floor.


  • Replace subfloor: $1.35-$1.85 per square foot
  • Install vinyl/linoleum: 
    • Rolled: $12-$18 per square yard (divide the square footage by 9)
    • Squares: $2-$3.50 per square foot
  • Install carpet: $16-$28 per square yard
  • Clean the carpet: around $50 per room
  • Install laminate wood: $2-$7 per square foot
  • Install engineered wood: $2.50-$8.50
  • Install prefinished hardwood: $3.50-$8.50
  • Install site-finished hardwood: $4.50-$8.50
  • Refinish hardwood: $1.5-$2.0
  • Install tile floor: $4-$16



Permit drawings by architect: $40-$70 per hour (depends on the complexity of the drawing. A typical one-story house will be around $1,000)

Permits: $35-$2,000 (depends on the project. A typical rehab will be around $400)

Inspections: $50-$100 each

General contractor:

  • Hire a GC to run the entire project: around 10% of the rehab cost
  • Hire a GC to just pull the permits: around $1,000


Mold needs moisture and food like wood, paper, drywall, insulation, and fabric, basically, all the materials the houses are built with. It becomes dangerous when it grows large and starts releasing its spores.


  • Sniff the air in the house: mold has a very distinctive smell
  • Visually inspect the areas where moisture is likely to occur including the A/C ducts
  • If you suspect that there is a mold problem, it is highly recommended to hire a qualified company to do an Air Quality Test (AQT) because there could be mold growing behind the walls so it’s not visible and you can’t smell it


  • Eliminate the moisture source
  • Remove the mold. Sometimes, you need to replace drywall, wood, or insulation
  • After remediation, perform the AQT to verify the results of the remediation
  • Air Quality Test: $100-$200 (note that you may have to do the AQT more than once)
  • Mold remediation: $500- $10,000 and up depending on the extent of the problem


There are several types of termites:

  • Subterranean termites: They are found all over the country except Alaska and more frequently in states with a warmer climate. They leave dirt trail behind which is one clue that the house probably has this type of termites.
  • Drywood termites: Found mostly in the southern states. They leave small oval fecal droppings as a clue.
  • Dampwood termites: They need moisture to survive so eliminating the source of the moisture and drying or replacing the wet wood will eliminate them.
  • Formosan termites: They are mostly found in states with a warmer climate. These are the most destructive and difficult to detect termite species (some people call the “super termites”)

Inspection: Take a pen or a key and randomly poke into places you expect to find termite damage. If you suspect that there is a problem, call a qualified pest control company to thoroughly inspect the house and give you a quote for treatment.


  • Inspection: In most cases free
  • Treatment:
    • Baiting: $4-$6 per linear foot
    • Chemical treatment: $4-$6 per linear foot
    • Fumigation: $1-$2 per square foot

After the successful treatment, do not forget to get a Termite Letter from the pest control company. It will cost you $40-$100 but you will need it to provide it to the buyer.

Finishing tasks

This includes doorknobs, deadbolts, door stoppers, A/C grates, wall plates, mini-blinds, etc.

Inspection: Walk through the house (or ask a friend to do it) and mark everything that bothers you or would make a bad impression to a potential buyer.

Tasks: $500-$2,000

Appliances: Since in most cases the kitchen sells the house, the approximate prices below are for cheap but presentable stainless steel appliances.

  • Refrigerator: $1,170
  • Range: $650
  • Dishwasher: $500 with $190 installation cost
  • Microwave: $250 with $120 installation cost
  • Washer and dryer: $1,00

House cleaning: $150-$300